A Pivotal Moment

This image from NASA EarthKAM shows pivot irrigation near the city of As Sulayyil Sulayel, Saudi Arabia. The edge of the Rub al-Khali or Empty Quarter is visible in the southeast.

In Saudi Arabia, center-pivot, swing-arm irrigated agriculture complexes such as the one imaged at Jabal Tuwayq (20.5N, 45.0 E) extract deep fossil water reserves to achieve food crop production self sufficiency in this desert environment. The significance of the Saudi expanded irrigated agriculture is that the depletion of this finite water resource is a short term solution to a long term need that will still exist when the water has been extracted.

Acquired by NASA Terra spacecraft on in 2011, this image shows the Wadi As-Sirhan Basin in northwest Saudi Arabia, which has been steadily developing agricultural fields using center pivot irrigation by tapping into fossil ground water.

Rover team members Kim Lichtenberg and Joseph Carsten watch motions of a test rover at NASA Jet Propulsion Laboratory, Pasadena, Calif., as the rover carries out commands for driving forward with an arc toward the right.

In this view from behind a test rover at NASA Jet Propulsion Laboratory, Pasadena, Calif., the rear wheels of the rover are turned toward the left, and the left-front wheel is turned toward the the right.

In the Al Jowf Province in northwestern Saudi Arabia, mining of fossil ground water has created an enormous agricultural enterprise, where tens of thousands of date palms and olive trees thrive in a hyper-arid environment. In a short 30-year period, the area has grown from 22 center-pivot irrigated fields to thousands. The Landsat TM image (Figure 1) was acquired March 30, 1989; the ASTER image on February 17, 2020. The images cover an area of 33.2 by 49 km, and are located at 30.1 degrees north, 38.3 degrees east. https://photojournal.jpl.nasa.gov/catalog/PIA23955

ISS010-E-05266 (28 October 2004) --- The Al Khufrah Oasis is featured in this image photographed by an Expedition 10 crewmember on the International Space Station (ISS). Green circles in the desert frequently indicate tracts of agriculture supported by center-pivot irrigation. The Al Khufrah Oasis in southeastern Libya (near the Egyptian border) is one of Libya’s largest agricultural projects, and is an easy-to-recognize landmark for orbiting crewmembers aboard the Station. The center-pivot irrigation system pumps water under pressure into a gantry or tubular arm from a central source. Anchored by a central pivot, the gantry slowly rotates over the area to be irrigated, thereby producing the circular patterns. Although the field diameters vary, these fields are approximately 0.6 mile (1 kilometer) in diameter. Darker colors indicate fields where such crops as wheat and alfalfa are grown. Lighter colors can indicate a variety of agricultural processes: fields that have been harvested recently; fields that are lying fallow; fields that have just been planted; or fields that have been taken out of production.

jsc2024e055754 (July 25, 2024) -- Dionne Hernandez-Lugo of the Gateway Program speaks about the pivotal role Gateway will play in the Artemis missions during the "Exploring the Moon: The Artemis Generation" panel at San Diego Comic-Con 2024. Photo Credit: NASA

jsc2024e055771 (July 26, 2024) -- Dr. Jon Olansen engages the audience at the Theater in the Woods during "The Historic Artemis II Mission" forum held at EAA AirVenture Oshkosh 2024. As the Gateway Program Manager, Olansen highlights Gateway's pivotal role in supporting the Artemis era of lunar exploration. Photo Credit: NASA/Andrew Carlsen

jsc2024e055753 (July 25, 2024) -- Dionne Hernandez-Lugo of the Gateway Program speaks about the pivotal role Gateway will play in the Artemis missions during the "Exploring the Moon: The Artemis Generation" panel at San Diego Comic-Con 2024. Photo Credit: NASA

This close-up view of the intensively cultivated Nile River flood plain near Cairo presents a sharp color contrast to the virtually non-vegetated, sandy desert, located to the west of the vegetated area. Some rectangular cultivated field patterns, as well as circular center pivot irrigation patterns, can be observed northwest of the Nile River flood plain. The world famous Giza Pyramids are located near the center of this photography (see highly reflective sand surfaces).

iss057e114766 (12/9/2018) --- European Space Agency (ESA) astronaut Alex Gerst is photographed with the Crystallization of RAS in Space (CASIS PCG 17) investigation. CASIS PCG 17grows crystals of KRAS proteins, which have a pivotal role in cell growth and death. Mutations in KRAS proteins are responsible for a third of all cancers and identifying the structure of these proteins is critical to developing therapeutics and treatments. Protein crystals grow larger and more perfectly in microgravity, allowing for detailed laboratory analysis of their structure back on Earth.

The rotating service structure on Launch Pad 39A has moved for the first time in more than a year due to maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15.

NASA demonstrates a key capability necessary for flight of the SLS (Space Launch System) rocket during the hot fire on Nov. 29, 2023. Crews gimbal, or pivot, the RS-25 engine around a central point during the almost 11-minute (650 seconds) hot fire on the Fred Haise Test Stand at NASA’s Stennis Space Center.

The rotating service structure on Launch Pad 39A is being moved for the first time in more than a year due to maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15.

The rotating service structure on Launch Pad 39A is being moved for the first time in more than a year due to maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15.

iss057e114765 (12/9/2018) --- European Space Agency (ESA) astronaut Alex Gerst is photographed with the Crystallization of RAS in Space (CASIS PCG 17) investigation. CASIS PCG 17grows crystals of KRAS proteins, which have a pivotal role in cell growth and death. Mutations in KRAS proteins are responsible for a third of all cancers and identifying the structure of these proteins is critical to developing therapeutics and treatments. Protein crystals grow larger and more perfectly in microgravity, allowing for detailed laboratory analysis of their structure back on Earth.

Engineers Ayrton Jordan (left) and Anthony Milana (right) at the NASA White Sands Test Facility (WSTF) in Las Cruces, N.M. install a metallic liner into the multipurpose pressure vessel scanner that could one day become part of a composite overwrapped pressure vessel. A slotted ball joint at the base of the rotary stage allows the tank to pivot resulting in helical scans that are more reliable when measuring interior and exterior 3D surface profiles. Photo Credit: (NASA/Reed P. Elliott)

STS035-73-082 (2-10 Dec 1990) --- This agricultural and ranching area, Rio Sao Francisco, Brazil (13.0S, 43.5W) has been under study for several years. See scene STS-31-92-045 for comparison. This area has many small single family subsistence farms, large square and rectangular commercial farms and pastures for livestock grazing. Over the several years of observation, the number and size of farms has increased and center-pivot, swing-arm irrigation systems have been installed.

NASA image acquired: March 29, 2011 This is the first image of Mercury taken from orbit with MESSENGER’s Narrow Angle Camera (NAC). MESSENGER’s camera system, the Mercury Dual Imaging System (MDIS), has two cameras: the Narrow Angle Camera and the Wide Angle Camera (WAC). Comparison of this image with MESSENGER’s first WAC image of the same region shows the substantial difference between the fields of view of the two cameras. At 1.5°, the field of view of the NAC is seven times smaller than the 10.5° field of view of the WAC. This image was taken using MDIS’s pivot. MDIS is mounted on a pivoting platform and is the only instrument in MESSENGER’s payload capable of movement independent of the spacecraft. The other instruments are fixed in place, and most point down the spacecraft’s boresight at all times, relying solely on the guidance and control system for pointing. The 90° range of motion of the pivot gives MDIS a much-needed extra degree of freedom, allowing MDIS to image the planet’s surface at times when spacecraft geometry would normally prevent it from doing so. The pivot also gives MDIS additional imaging opportunities by allowing it to view more of the surface than that at which the boresight-aligned instruments are pointed at any given time. On March 17, 2011 (March 18, 2011, UTC), MESSENGER became the first spacecraft ever to orbit the planet Mercury. The mission is currently in the commissioning phase, during which spacecraft and instrument performance are verified through a series of specially designed checkout activities. In the course of the one-year primary mission, the spacecraft's seven scientific instruments and radio science investigation will unravel the history and evolution of the Solar System's innermost planet. Visit the Why Mercury? section of this website to learn more about the science questions that the MESSENGER mission has set out to answer. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a></b> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. <b>Follow us on <a href="http://twitter.com/NASA_GoddardPix" rel="nofollow">Twitter</a></b> <b>Join us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a></b>

STS062-151-220 (4-18 March 1994) --- Great numbers of circular, center-pivot irrigation plots appear in this west-looking view of the northern Saudi Arabia (center to lower left). So many plots now exist that the face of Saudi Arabia as seen from low earth orbit has changed. Until a few years ago, there were only a few scattered center-pivots. Now the entire swath of country between the shifting sands of the Ad Dahna Sand Sea (light colors center and right) and the almost soilless Nejd Plateau (left) has been darkened by thousands of these agricultural fields. The Nejd Plateau is a mass of dark rocks, some volcanic, in NW Saudi Arabia. Water from this higher country flows east towards the agricultural region where it is pumped up from underground aquifers. The weep of the Ad Dahna Sand Sea is one of the major features of Saudi Arabia (center and right) as seen from the orbiter. The dunes follow the trend of regional winds (northwesterly in the center of the view) which circulate around the Nejd plateau. The north end of the Red Sea can be seen top left with the Sinai Peninsula and Mediterranean are just visible center top. Iraq is under cloud top right.

KENNEDY SPACE CENTER, FLA. -- The rotating service structure on Launch Pad 39A is being moved for the first time in more than a year due to maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15. Photo credit: NASA/George Shelton

STS054-152-189 (13-19 Jan. 1993) --- This near-vertical color photograph shows the very diverse landscape that is part of the great Sahara Desert of north Africa. Specifically, the vast expanse of sand dunes, located in the extreme southwestern corner of Libya, is known as the Murzuk Sand Sea. Close inspection of this photograph shows the agricultural village of Murzuk as evidenced by the numerous center pivot irrigation patterns at the edge of the Murzuk Sand Sea. The very rugged, dissected terrain to the west of this sand sea is the eastern tip of the Tassili N'ajjer Mountains and the Tadrart Plateau that are in neighboring Algeria. Several smaller areas of sand dunes are interspersed between the major areas of rock outcrops. The photograph was taken with a Linhof camera.

KENNEDY SPACE CENTER, FLA. -- The rotating service structure on Launch Pad 39A has been fully opened for the first time in more than a year due to maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15. Photo credit: NASA/George Shelton

41C-31-1002 (6-13 April 1984) --- Though previous photographs of this area have been taken prior to 41-C, that mission?s photography represents the best ever of ground water irrigation in Near East deserts. The system here is located in northeast Saudi Arabia, in the vicinity of Al Hufuf. Designed for use in the American west, the center pivot irrigation method pumps water from the ground and broadcasts it in a half-mile diameter circle from a mobile sprinkler system. This frame was one of the visuals used by the 41-C astronauts at their post-flight press conference.

Workers on Launch Pad 39A get ready to begin the movement of the rotating service structure above them. The RSS has not been rotated for more than a year during the maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15.

KENNEDY SPACE CENTER, FLA. -- The rotating service structure on Launch Pad 39A is being moved for the first time in more than a year due to maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15. Photo credit: NASA/George Shelton

In the middle of the Arabian desert the city Green Oasis Wadi Al Dawasir is being developed as a new urban center for the Wadi Al Dawasir region of Saudi Arabia, as shown in this image from NASA Terra spacecraft. Huge solar fields supply the entire city and the surrounding region with energy. Hundreds of circular agricultural fields are fed by center pivot irrigation apparatus, drawing water from subterranean aquifers. The image was acquired March 30, 2013, covers an area of 30 x 45 km, and is located at 20.2 degrees north, 44.8 degrees east. http://photojournal.jpl.nasa.gov/catalog/PIA20077

The rotating service structure on Launch Pad 39A has been fully opened for the first time in more than a year due to maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15. Photo credit: NASA/George Shelton

The STS-74 crew patch depicts the orbiter Atlantis docked to the Russian Space Station Mir. The central focus is on the Russian-built docking module, drawn with shading to accentuate its pivotal importance to both STS-74 and the NASA-Mir Program. The rainbow across the horizon represents the Earth's atmosphere, the thin membrane protecting all nations, while the three flags across the bottom show those nations participating in STS-74: Russia, Canada, and the United States. The sunrise is symbolic of the dawn of a new era in NASA space flight , that of International Space Station construction.

NACA High-Speed Flight Station test pilot Stan Butchart flying the Iron Cross, the mechanical reaction control simulator. High-pressure nitrogen gas expanded selectively, by the pilot, through the small reaction control thrusters maneuvered the Iron Cross through the three axes. The exhaust plume can be seen from the aft thruster. The tanks containing the gas can be seen on the cart at the base of the pivot point of the Iron Cross. NACA technicians built the iron-frame simulator, which matched the inertia ratios of the Bell X-1B airplane, installing six jet nozzles to control the movement about the three axes of pitch, roll, and yaw.

The Nubian Sandstone Aquifer System is the world's largest fossil water aquifer system. It covers an estimated area of 2.6 million square kilometers, including parts of Sudan, Chad, Libya, and most of Egypt. In the southwestern part of Egypt, the East Oweinat development project uses central pivot irrigation to mine the fossil water for extensive agricultural development. Crops include wheat and potatoes; they are transported via the airport on the eastern side. The image was acquired October 12, 2015, covers an area of 33.3 by 47.2 km, and is located near 22.6 degrees north, 28.5 degrees east. https://photojournal.jpl.nasa.gov/catalog/PIA24616

KENNEDY SPACE CENTER, FLA. -- Workers on Launch Pad 39A get ready to begin the movement of the rotating service structure above them. The RSS has not been rotated for more than a year during the maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- The rotating service structure on Launch Pad 39A has moved for the first time in more than a year due to maintenance and upgrades on the pad. Some of the work included sandblasting the structure to remove rust and repainting. In addition, the RSS was jacked up and a new upper-bearing race assembly installed where the RSS pivots against the fixed service structure and a half-inch steel plate added. Pad 39A is being made ready for its first launch in four years, the upcoming STS-117 on March 15. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, Fla. -- Workers watch the rollback of the Rotating Service Structure (left) from around Space Shuttle Discovery on Launch Pad 39B. Poised above the orange external tank is the Gaseous Oxygen Vent Arm with the “beanie cap,” a vent hood. The RSS provides protected access to the orbiter for changeout and servicing of payloads. It is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad’s flame trench. Space Shuttle Discovery is scheduled to launch March 8 at 6:42 a.m. EST on the eighth construction flight to the International Space Station. It carries the Multi-Purpose Logistics Module Leonardo, the primary delivery system used to resupply and return Station cargo requiring a pressurized environment. Leonardo will deliver up to 10 tons of laboratory racks filled with equipment, experiments and supplies for outfitting the newly installed U.S. Laboratory Destiny

CAPE CANAVERAL, Fla. – With a full moon silhouetted in the night sky, the rotating service structure is ready to be rolled from around space shuttle Endeavour into park position on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The rollback is in preparation for Endeavour's liftoff on the STS-126 mission with a crew of seven. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The STS-126 mission will be the 124th space shuttle flight and the 27th flight to the International Space Station. The mission will feature four spacewalks and work that will prepare the space station to house six crew members for long- duration missions. Liftoff is scheduled for 7:55 p.m. EST Nov. 14. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, Fla. -- Less than 24 hours before launch of STS-102, photographers capture the rollback of the Rotating Service Structure from around Space Shuttle Discovery on Launch Pad 39B. Poised above the external tank is the Gaseous Oxygen Vent Arm with the “beanie cap,” a vent hood. The RSS provides protected access to the orbiter for changeout and servicing of payloads. It is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad’s flame trench. Space Shuttle Discovery is scheduled to launch March 8 at 6:42 a.m. EST on the eighth construction flight to the International Space Station. It carries the Multi-Purpose Logistics Module Leonardo, the primary delivery system used to resupply and return Station cargo requiring a pressurized environment. Leonardo will deliver up to 10 tons of laboratory racks filled with equipment, experiments and supplies for outfitting the newly installed U.S. Laboratory Destiny

KENNEDY SPACE CENTER, FLA. -- The mobile launcher platform with space shuttle Endeavour on top comes to rest on Launch Pad 39A. Prior to launch on the STS-123 mission, Endeavour will undergo three weeks of processing at the pad. At left is the rotating service structure, or RSS, which will pivot and close around the shuttle. The RSS provides protected access to the orbiter for crew entry and servicing of payloads at the pad. The journey from the Vehicle Assembly Building began at 11:24 p.m. on Feb. 17, approximately 30 minutes before it's scheduled start time due to favorable weather conditions. The shuttle arrived at the launch pad at 4:45 a.m. Monday and was hard down at 6:22 a.m. On the mission, Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is targeted for March 11. Photo credit: NASA/Amanda Diller

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the rotating service structure has been moved into place around space shuttle Endeavour. The RSS provides protected access to the shuttle for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The RSS rotates through 120 degrees (one-third of a circle) on a radius of 160 feet. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. Endeavour is targeted to launch June 13 on its STS-127 mission to the International Space Station. Photo credit: NASA/Tim Jacobs

S73-20622 (March 1973) --- Scientist-astronaut Joseph P. Kerwin, science pilot of the first manned Skylab mission, demonstrates the Body Mass Measurement Experiment (M172) during Skylab training at the Johnson Space Center. Dr. Kerwin is in the work and experiments area of the crew quarters of the Skylab Orbital Workshop (OWS) trainer at JSC. The M172 experiment will demonstrate body mass measurement in a null gravity environment, validate theoretical behavior of this method, and support those medical experiments for which body mass measurements are required. The data to be collected in support of M172 are: preflight calibration of the body mass measurement device and measurements of known masses up to 100 kilograms (220 pounds) three times during each Skylab mission. The device, a spring/flexure pivot-mounted chair, will also be used for daily determination of the crewmen?s weight, which will be manually logged and voice recorded for subsequent telemetered transmission. Photo credit: NASA

STS087-703-089 (19 November &#0150; 5 December 1997) --- Featured in this view is center pivot irrigation in central Saudi Arabia. Abundant petroleum has provided the energy source for deep-well pumps that tap groundwater stored in bedrock many thousands of years ago when the climate was much wetter. The fields are carved out of ancient alluvial fan deposits, also formed when rainfall was much greater; the fields are pushed right to the edge of the Nafud al Mazhur (sand sea), representative of the present climate. The mining of petroleum and groundwater has enabled Saudi Arabia to become an exporter of wheat and other commodities, in addition to the oil for which it is famous. This picture is one of the 70mm Earth observation visuals used by the crew at its post flight presentation events.

STS040-151-126 (5-14 June 1991) --- Croplands of the San Luis Valley stand out exceptionally clearly from low Earth orbit. The Rio Grande flows through the valley. Circular center pivot irrigation patterns have almost completely replaced the earlier rectangular grid pattern. Pinto beans are the specialty of the area. The Great Sand Dunes National Monument appears in fine detail near the center of the picture. The sands of these dunes have been blown from the valley floor by westerly winds in the course of the last few tens of thousands of years, now banked up against the foot of the Sangre de Christo Mountains (snowcapped peaks reach over 14000 feet). The town of Alamosa lies on the Rio Grande. The San Juan Mountains appear at the bottom left.

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the orbiter access arm and White Room are extended toward space shuttle Endeavour after rollback of the rotating service structure. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The STS-126 mission will be the 124th space shuttle flight and the 27th flight to the International Space Station. The mission will feature four spacewalks and work that will prepare the space station to house six crew members for long- duration missions. Liftoff is scheduled for 7:55 p.m. EST Nov. 14. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, Fla. -- Workers watch the rollback of the Rotating Service Structure (left) from around Space Shuttle Discovery on Launch Pad 39B. Poised above the orange external tank is the Gaseous Oxygen Vent Arm with the “beanie cap,” a vent hood. The RSS provides protected access to the orbiter for changeout and servicing of payloads. It is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad’s flame trench. Space Shuttle Discovery is scheduled to launch March 8 at 6:42 a.m. EST on the eighth construction flight to the International Space Station. It carries the Multi-Purpose Logistics Module Leonardo, the primary delivery system used to resupply and return Station cargo requiring a pressurized environment. Leonardo will deliver up to 10 tons of laboratory racks filled with equipment, experiments and supplies for outfitting the newly installed U.S. Laboratory Destiny

CAPE CANAVERAL, Fla. – Viewed from the side of Launch Pad 39A at NASA's Kennedy Space Center in Florida, the rotating service structure has been moved into place around space shuttle Endeavour. The RSS provides protected access to the shuttle for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The RSS rotates through 120 degrees (one-third of a circle) on a radius of 160 feet. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. Endeavour is targeted to launch June 13 on its STS-127 mission to the International Space Station. Photo credit: NASA/Tim Jacobs

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the orbiter access arm and White Room are extended toward space shuttle Endeavour after rollback of the rotating service structure. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The STS-126 mission will be the 124th space shuttle flight and the 27th flight to the International Space Station. The mission will feature four spacewalks and work that will prepare the space station to house six crew members for long- duration missions. Liftoff is scheduled for 7:55 p.m. EST Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers keep watch as the rotating service structure, or RSS, is moved to enclose space shuttle Endeavour. The RSS provides protected access to the shuttle for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The RSS rotates through 120 degrees (one-third of a circle) on a radius of 160 feet. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. Endeavour is targeted to launch June 13 on its STS-127 mission to the International Space Station. Photo credit: NASA/Tim Jacobs

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the orbiter access arm and White Room are extended toward space shuttle Endeavour after rollback of the rotating service structure. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The STS-126 mission will be the 124th space shuttle flight and the 27th flight to the International Space Station. The mission will feature four spacewalks and work that will prepare the space station to house six crew members for long- duration missions. Liftoff is scheduled for 7:55 p.m. EST Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, space shuttle Endeavour is revealed after the rotating service structure begins to roll away. The rollback is in preparation for Endeavour's liftoff on the STS-126 mission with a crew of seven. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The STS-126 mission will be the 124th space shuttle flight and the 27th flight to the International Space Station. The mission will feature four spacewalks and work that will prepare the space station to house six crew members for long- duration missions. Liftoff is scheduled for 7:55 p.m. EST Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers begin closing the rotating service structure, or RSS, around space shuttle Endeavour. The RSS provides protected access to the shuttle for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The RSS rotates through 120 degrees (one-third of a circle) on a radius of 160 feet. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. Endeavour is targeted to launch June 13 on its STS-127 mission to the International Space Station. Photo credit: NASA/Tim Jacobs

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers talk to the driver of the rotating service structure, or RSS, before it is moved around space shuttle Endeavour. The RSS provides protected access to the shuttle for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The RSS rotates through 120 degrees (one-third of a circle) on a radius of 160 feet. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. Endeavour is targeted to launch June 13 on its STS-127 mission to the International Space Station. Photo credit: NASA/Tim Jacobs

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker prepares the rail for the closing of the rotating service structure around space shuttle Endeavour. The RSS provides protected access to the shuttle for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The RSS rotates through 120 degrees (one-third of a circle) on a radius of 160 feet. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. Endeavour is targeted to launch June 13 on its STS-127 mission to the International Space Station. Photo credit: NASA/Tim Jacobs

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to drive the truck that moves the rotating service structure, or RSS. The RSS will be moved around space shuttle Endeavour. The RSS provides protected access to the shuttle for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The RSS rotates through 120 degrees (one-third of a circle) on a radius of 160 feet. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. Endeavour is targeted to launch June 13 on its STS-127 mission to the International Space Station. Photo credit: NASA/Tim Jacobs

STS083-747-033 (4-8 April 1997) --- Center Pivot Irrigation, in Saudi Arabia. This irrigation project in Saudi Arabia is typical of many isolated irrigation projects scattered throughout the arid and hyper-arid regions of the Earth. Fossil water is mined from depths as great as 3,000 feet, pumped to the surface, and distributed via large center pivot irrigation feeds. The circles of green irrigated vegetation may comprise a variety of agricultural commodities from alfalfa to wheat. Diameters of the normally circular fields range from a few hundred meters to as much as 2 miles. The projects often trace out a narrow, sinuous, and seemingly random path. Actually, engineers generally seek ancient river channels now buried by the sand seas. The fossil waters mined in these projects accumulated during periods of wetter climate in the Pleistocene glacial epochs, between 10,000 to 2 million years ago, and are not being replenished under current climatic conditions. The projects, therefore, will have limited production as the reservoirs are drained. Water, of course, is the key to agriculture in Saudi Arabia. The Kingdom has implemented a multifaceted program to provide the vast supplies of water necessary to achieve the spectacular growth of the agricultural sector. A network of dams has been built to trap and utilize precious seasonal floods. Vast underground water reservoirs have been tapped through deep wells. Desalination plants have been built to produce fresh water from the sea for urban and industrial use, thereby freeing other sources for agriculture. Facilities have also been put into place to treat urban and industrial run-off for agricultural irrigation. These efforts collectively have helped transform vast tracts of the desert into fertile farmland. Land under cultivation has grown from under 400,000 acres in 1976 to more than 8 million acres in 1993.

ISS029-E-037471 (3 Nov. 2011) --- Egypt?Israel borderlands, northern Sinai Peninsula and northern Negev Desert are featured in this image photographed by an Expedition 29 crew member on the International Space Station. A clearly visible line that marks approximately 50 kilometers of the international border between Egypt and Israel?10-60 kilometers from the Mediterranean Sea to the northwest (not shown)?crosses the center of this photograph from left to right. The reason for the color difference is likely the slightly higher level of grazing by the animal herds of Bedouin herdsmen on the Egyptian side of the border. A major highway also follows the border, making the demarcation more prominent in this recent image taken from the space station. A patch of the Gaza Strip appears under scattered cloud at far right. In the arid to semiarid climate of the region illustrated in the image the natural grass vegetation is sparse at best. Irrigated commercial agriculture in Israel nearest the Mediterranean coast appears as a series of large angular patterns and circular center pivot fields, with darker greens indicating growing crops (right). Smaller plot sizes appear on the Egyptian side of the border at upper right. The image shows how the active sand dunes, which dominate most of the landscape in this view, mark the southern limit of the agriculture.

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the rotating service structure has rolled away to uncover space shuttle Endeavour. First motion was at 8:23 a.m. and rollback was complete at 8:55 a.m. Above the orange external tank is seen the "beanie cap" at the end of the gaseous oxygen vent arm, extending from the fixed service structure. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the space shuttle vehicle. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- Rollback of the rotating service structure, or RSS, begins on Launch Pad 39A, revealing Space Shuttle Atlantis, bathed in lights. Rollback is one of the milestones in preparation for the launch of mission STS-117 on June 8 and started at 10:56 p.m. EDT. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 118th shuttle flight and the 21st U.S. flight to the International Space Station and will deliver and install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After rollback of the rotating service structure (RSS) on Launch Pad 39B, Space Shuttle Discovery stands bathed in lights from the RSS and fixed service structure. The rollback was in preparation for launch July 1 on mission STS-121. Extending toward the cockpit of the shuttle is the orbiter access arm with the White Room extended. The White Room provides access into the orbiter for the astronauts. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett

STS074-S-001 (July 1995) --- Designed by crew members, this STS-74 crew patch depicts the space shuttle Atlantis docked to Russia's Mir Space Station. The central focus is on the Russian-built Docking Module (DM), drawn with shading to accentuate its pivotal importance to both mission STS-74 and the NASA - Mir Program. The rainbow across the horizon represents Earth's atmosphere, the thin membrane protecting all nations, while the three flags across the bottom show those nations participating in STS-74 - Russia, Canada and the United States. The sunrise is symbolic of the dawn of a new era in NASA space flight - that of space station construction. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the rotating service structure is rolling on its axis to uncover space shuttle Endeavour. First motion was at 8:23 a.m. and rollback was complete at 8:55 a.m. Above the orange external tank is seen the "beanie cap" at the end of the gaseous oxygen vent arm, extending from the fixed service structure. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the space shuttle vehicle. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians in the control booth get ready to roll the rotating service structure, or RSS, above them away from space shuttle Endeavour. First motion was at 10:39 a.m. EDT. The rollback is in preparation for Endeavour's liftoff June 13 on the STS-127 mission with a crew of seven. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The launch will be Endeavour's 23rd flight. The shuttle will carry the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, on STS-127. The mission is the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the space station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians in the control booth roll the rotating service structure, or RSS, away from space shuttle Endeavour. First motion was at 10:39 a.m. EDT. The rollback is in preparation for Endeavour's liftoff June 13 on the STS-127 mission with a crew of seven. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The launch will be Endeavour's 23rd flight. The shuttle will carry the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, on STS-127. The mission is the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the space station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. -- After rollback of the rotating service structure, or RSS, on Launch Pad 39A, Space Shuttle Atlantis stands bathed in lights. Rollback is one of the milestones in preparation for the launch of mission STS-117 on June 8. Rollback started at 10:56 p.m. and was complete at 11:34 p.m EDT. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 118th shuttle flight and the 21st U.S. flight to the International Space Station and will deliver and install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – Lighted against the black of night, space shuttle Endeavour is revealed after rollback of the rotating service structure. The rollback is in preparation for liftoff on the STS-126 mission with a crew of seven. Above Endeavour's external tank is the vent hood, known as the "beanie cap," at the end of the gaseous oxygen vent arm, extending from the fixed service structure. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the space shuttle vehicle. Below is the orbiter access arm with the White Room at the end, flush against the shuttle. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The STS-126 mission will be the 124th space shuttle flight and the 27th flight to the International Space Station. The mission will feature four spacewalks and work that will prepare the space station to house six crew members for long- duration missions. Liftoff is scheduled for 7:55 p.m. EST Nov. 14. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - A fish-eye camera lens captures the movement of the rotating service structure (RSS) at left as it moves away from Space Shuttle Discovery in preparation for the July 1 launch from Launch Pad 39B. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The setting sun backlights space shuttle Discovery on Launch Pad 39A at NASA's Kennedy Space Center just before rollback of the rotating service structure in preparation for launch on the STS-124 mission. The structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. The STS-124 mission is the second of three flights launching components to complete the Japan Aerospace Exploration Agency's Kibo laboratory. The shuttle crew will install Kibo's large Japanese Pressurized Module and its remote manipulator system, or RMS. The 14-day flight includes three spacewalks. Launch is scheduled for 5:02 p.m. May 31. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. -- On top of Launch Pad 39A at NASA's Kennedy Space Center, space shuttle Endeavour waits for liftoff on the STS-123 mission. The rotating service structure was rolled back starting at 8:23 a.m. and complete at 8:55 a.m. At far right is the 300,000-gallon water tank that provides the water for sound suppression during liftoff. Signs on the gate across the pad illustrate the primary payloads on the mission: the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Liftoff is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In preparation for the July 1 launch of Space Shuttle Discovery on mission STS-121, the Launch Pad 39B rotating service structure (RSS) enclosing the shuttle rolls away. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett

ISS005-E-9984 (17 August 2002) --- This digital still photograph, taken from the International Space Station (ISS) during its fifth staffing, depicts both agriculture and the petroleum industry, which compete for land use near Denver City, Texas. The photo was recently released by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. The area is southwest of Lubbock near the New Mexico border. According to analysts studying the station imagery, the economy of this region is almost completely dependent on its underground resources of petroleum and water. Both resources result in distinctive land use patterns visible from space. Historically this area has produced vast quantities of oil and gas since development began in the 1930s. A fine, light-colored grid of roads and pipelines connect well sites over this portion of the Wasson Oil Field, one of the state&#0146;s most productive. Since the 1940s, agricultural land use has shifted from grazing to irrigated cultivation of cotton, sorghum, wheat, hay, and corn. The water supply is drawn from wells tapping the vast Ogallala Aquifer. Note the large, circular center-pivot irrigation systems in the lower corners of the image. The largest is nearly a mile in diameter.

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, space shuttle Endeavour is revealed after the rollback of the rotating service structure, or RSS. In the foreground is the flame trench, which the mobile launcher platform straddles. On top of the external fuel tank is the oxygen vent hood, called the "beanie cap," which is designed to vent gaseous oxygen vapors away from the shuttle. The rollback is preparation for Endeavour's liftoff June 13 on the STS-127 mission with a crew of seven. First motion was at 10:39 a.m. EDT and completed at 11:18 a.m. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The launch will be Endeavour's 23rd flight. The shuttle will carry the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, on STS-127. The mission is the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the space station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. – Visible after rollback of the rotating service structure and looming like giants against the sky are the solid rocket boosters, external tank and space shuttle Endeavour, poised for launch on Launch Pad 39A at NASA's Kennedy Space Center in Florida. Near the top of Endeavour is the White Room, at the end of the orbiter access arm. The White Room provides entry into the shuttle for the astronauts. The rollback is preparation for Endeavour's liftoff June 13 on the STS-127 mission with a crew of seven. First motion was at 10:39 a.m. EDT and completed at 11:18 a.m. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The launch will be Endeavour's 23rd flight. The shuttle will carry the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, on STS-127. The mission is the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the space station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. -- With the rotating service structure rolled away on Launch Pad 39A at NASA's Kennedy Space Center, space shuttle Endeavour is in full view. First motion was at 8:23 a.m. and rollback was complete at 8:55 a.m. Behind the shuttle with its large, orange external tank is the blue Atlantic Ocean. Extending toward Endeavour from the left is the orbiter access arm with the White Room at the end, flush against the shuttle. The crew gains access into the orbiter through the White Room. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

ISS026-E-025373 (10 Feb. 2011) --- Agricultural fields near Perdizes, Minas Gerais, Brazil are featured in this image photographed by an Expedition 26 crew member on the International Space Station. This detailed photograph illustrates diverse agricultural landscape patterns in the western part of the Brazilian State of Minas Gerais. Perhaps most widely known for its mineral wealth, Minas Gerais is also a large agricultural producer in Brazil. The fields in the image are located to the southwest of the city of Perdizes, which means “partridges” in Portuguese. A mix of regularly-gridded polygonal fields, and circular center-pivot fields, marks the human land use of the region. Small tributary streams (and their adjacent floodplains) of the Araguari River extend like fingers throughout the agricultural landscape. The visual diversity of field forms is matched by the variety of crops produced here: sunflowers, wheat, potatoes, coffee, rice, soybeans, and corn are among the agricultural products of the region. While the Northern Hemisphere is still in the grip of winter, crops are growing in the Southern Hemisphere as indicated by the many green fields in the image. Fallow fields—fields not in active agricultural use—display the violet, reddish to light tan soils common to this part of Brazil. The darker soils are often rich in iron and aluminum oxides, and are typical of highly weathered soil material that forms in hot, humid climates.

KENNEDY SPACE CENTER, FLA. -- With the rotating service structure rolled away on Launch Pad 39A at NASA's Kennedy Space Center, space shuttle Endeavour is in full view. First motion was at 8:23 a.m. and rollback was complete at 8:55 a.m. Extending toward Endeavour from the left is the orbiter access arm with the White Room at the end, flush against the shuttle. The crew gains access into the orbiter through the White Room. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- From across the marsh next to Launch Pad 39A at NASA's Kennedy Space Center, space shuttle Endeavour is in full view after rollback of the rotating service structure. First motion was at 8:23 a.m. and rollback was complete at 8:55 a.m. At far right is the 300,000-gallon water tank that provides the water for sound suppression during liftoff. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the oxygen vent hood, called the "beanie cap," is positioned above the external fuel tank of space shuttle Endeavour following the rollback of the rotating service structure, or RSS, at left. The beanie cap is designed to vent gaseous oxygen vapors away from the shuttle. The rollback is preparation for Endeavour's liftoff June 13 on the STS-127 mission with a crew of seven. First motion was at 10:39 a.m. EDT and completed at 11:18 a.m. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The launch will be Endeavour's 23rd flight. The shuttle will carry the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, on STS-127. The mission is the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the space station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. – After rollback of the rotating service structure on Launch Pad 39A at NASA's Kennedy Space Center in Florida, space shuttle Endeavour, with its external fuel tank and solid rocket boosters, are poised for launch. The rollback is preparation for Endeavour's liftoff June 13 on the STS-127 mission with a crew of seven. First motion was at 10:39 a.m. EDT and completed at 11:18 a.m. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The launch will be Endeavour's 23rd flight. The shuttle will carry the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, on STS-127. The mission is the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the space station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, workers check one of the two trucks that move the rotating service structure (RSS). In preparation for the July 1 launch of Space Shuttle Discovery on mission STS-121, the RSS is being rolled away from the shuttle. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett

Center pivot irrigation systems create red circles of healthy vegetation in this image of croplands near Garden City, Kansas. This image was acquired by Landsat 7’s Enhanced Thematic Mapper plus (ETM+) sensor on September 25, 2000. This is a false-color composite image made using near infrared, red, and green wavelengths. The image has also been sharpened using the sensor’s panchromatic band. Credit: NASA/GSFC/Landsat <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a></b> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. <b>Follow us on <a href="http://twitter.com/NASA_GoddardPix" rel="nofollow">Twitter</a></b> <b>Join us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a></b>

CAPE CANAVERAL, Fla. – The open rotating service structure, or RSS (left), on Launch Pad 39A at NASA's Kennedy Space Center in Florida reveals space shuttle Endeavour poised for launch. The RSS was rotated to its open position in preparation for Endeavour's liftoff June 13 on the STS-127 mission with a crew of seven. First motion was at 10:39 a.m. EDT and completed at 11:18 a.m. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The launch will be Endeavour's 23rd flight. The shuttle will carry the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, on STS-127. The mission is the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the space station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Jim Grossmann

STS-56 Earth observation of the northeastern Nile Delta was photographed from the Earth-orbiting Discovery, Orbiter Vehicle (OV) 103. The branch of the Nile featured in the frame is Daimietta. The Suez Canal marks the boundary of the Nile Delta agriculture and the Sinai Desert to the right. Lake Masada, the dark waterlogged area to the west (left) of Port Said is becoming more saline as the Aswan Dam has reduced sediment downstream. This sediment reduction, according to NASA scientists studying the STS-56 photography, has resulted in increased coastal erosion and the intrusion of a salt-water lens to the ground water, particularly in the northeastern portions of the delta. Center pivot irrigation fields are located along either side of the Ramses Canal, which connects the Daimietta Nile with Great Bitter Lake. This canal has been re-dug three or four times in the past 3,000 years. Historians note that the canal's most famous use was as the departure point of the fleet of Pharaoh Necho. The fleet circumnavigated Africa clockwise from the head of the Red Sea to the Mediterranean coast of the Nile (probably the Rosetta Nile) in a three-year voyage circa 660 BC.

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the rotating service structure is rolling on its axis to uncover space shuttle Endeavour. First motion was at 8:23 a.m. and rollback was complete at 8:55 a.m. The structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

S72-53094 (For release February 1973) --- This is the emblem for the third manned Skylab mission. It will be a mission of up to 56 days. Skylab is an experimental space station consisting of a 100-ton laboratory complex in which medical, scientific and technological experiments will be performed in Earth orbit. The members of the crew will be astronaut Gerald P. Carr, commander; scientist-astronaut Edward G. Gibson, science pilot; and astronaut William R. Pogue, pilot. The symbols in the patch refer to the three major areas of investigation proposed in the mission. The tree represents man's natural environment and relates directly to the Skylab mission objectives of advancing the study of Earth resources. The hydrogen atom, as the basic building block of the universe, represents man's exploration of the physical world, his application of knowledge, and his development of technology. Since the sun is composed primarily of hydrogen, it is appropriate that the symbol refers to the solar physics mission objectives. The human silhouette represents mankind and the human capacity to direct technology with a wisdom tempered by regard for his natural environment. It also directly relates to the Skylab medical studies of man himself. The rainbow, adopted from the Biblical story of the flood, symbolizes the promise that is offered man. It embraces man and extends to the tree and the hydrogen atom emphasizing man's pivotal role in the conciliation of technology with nature. Photo credit: NASA

KENNEDY SPACE CENTER, FLA. - Viewed from an upper level of the fixed service structure on Launch Pad 39B, Space Shuttle Discovery looms over the pad and surrounding area after rollback of the rotating service structure (RSS). The rollback was in preparation for launch July 1 on mission STS-121. Extending toward the cockpit of the shuttle is the orbiter access arm with the White Room extended. The White Room provides access into the orbiter for the astronauts. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - After rollback of the rotating service structure (RSS) on Launch Pad 39B, Space Shuttle Discovery stands bathed in lights from the RSS and fixed service structure. The rollback was in preparation for launch July 1 on mission STS-121. Extending toward the cockpit of the shuttle is the orbiter access arm with the White Room extended. The White Room provides access into the orbiter for the astronauts. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, space shuttle Endeavour is revealed after the rollback of the rotating service structure, or RSS. On the left of Endeavour is the White Room, at the end of the orbiter access arm. The White Room provides entry into the shuttle for the astronauts. The rollback is preparation for Endeavour's liftoff June 13 on the STS-127 mission with a crew of seven. First motion was at 10:39 a.m. EDT and completed at 11:18 a.m. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The launch will be Endeavour's 23rd flight. The shuttle will carry the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, on STS-127. The mission is the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the space station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. – Under a full moon on Launch Pad 39A at NASA's Kennedy Space Center in Florida, space shuttle Discovery is revealed after the rotating service structure has been rolled back. The rollback is in preparation for Discovery's liftoff on the STS-119 mission with a crew of seven. The rotating structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The mission is the 28th to the International Space Station and the 125th space shuttle flight. Discovery will deliver the final pair of power-generating solar array wings and the S6 truss segment. Installation of S6 will signal the station's readiness to house a six-member crew for conducting increased science. Liftoff of Discovery is scheduled for 9:20 p.m. EDT on March 11. Photo courtesy of NASA/Bill Ingalls

KENNEDY SPACE CENTER, FLA. -- Following sunrise on a cloudy Florida day, Space Shuttle Atlantis awaits launch atop a mobile launch platform at Launch Pad 39A. Rollback of the pad's rotating service structure, or RSS, is one of the milestones in preparation for the launch of mission STS-117 on June 8. Rollback started at 10:56 p.m. EDT June 7 and was complete at 11:34 p.m. The RSS, the massive structure to the left of the shuttle, provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 118th shuttle flight and the 21st U.S. flight to the International Space Station and will deliver and install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. -- Flags wave near Launch Pad 39A where space shuttle Endeavour waits for liftoff. The rotating service structure was rolled back starting at 8:23 a.m. and complete at 8:55 a.m. Above the orange external tank is seen the "beanie cap" at the end of the gaseous oxygen vent arm, extending from the fixed service structure. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the space shuttle vehicle. Below is the orbiter access arm with the White Room at the end, flush against the shuttle. The crew gains access into the orbiter through the White Room. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, rollback of the rotating service structure reveals space shuttle Endeavour atop the mobile launcher platform. First motion was at 8:23 a.m. and rollback was complete at 8:55 a.m. Above the orange external tank is seen the "beanie cap" at the end of the gaseous oxygen vent arm, extending from the fixed service structure. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the space shuttle vehicle. Below is the orbiter access arm with the White Room at the end, flush against the shuttle. The crew gains access into the orbiter through the White Room. On either side of the main engines and below the wings are the tail service masts, which provide several umbilical connections to the orbiter, including a liquid-oxygen line through one and a liquid-hydrogen line through another. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the rotating service structure has rolled away to uncover space shuttle Endeavour, resting on the mobile launcher platform. First motion was at 8:23 a.m. and rollback was complete at 8:55 a.m. Above the orange external tank is seen the "beanie cap" at the end of the gaseous oxygen vent arm, extending from the fixed service structure. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the space shuttle vehicle. Below is the orbiter access arm with the White Room at the end, flush against the shuttle. The crew gains access into the orbiter through the White Room. On either side of the main engines and below the wings are the tail service masts, which provide several umbilical connections to the orbiter, including a liquid-oxygen line through one and a liquid-hydrogen line through another. The rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Launch is scheduled for 2:28 a.m. EDT March 11. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center, the rotating service structure begins rolling on its axis to uncover space shuttle Discovery in preparation for launch on the STS-124 mission. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks (one is seen at bottom left) that move along circular twin rails installed flush with the pad surface. First motion was at 8:33 p.m. and rollback was complete at 9:07 p.m. The structure provides protected access to the shuttle for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots on a vertical axis on the west side of the pad's flame trench. After the RSS is rolled back, the orbiter is ready for fuel cell activation and external tank cryogenic propellant loading operations. The pad is cleared to the perimeter gate for operations to fill the external tank with about 500,000 gallons of cryogenic propellants used by the shuttle’s main engines. This is done at the pad approximately eight hours before the scheduled launch. The STS-124 mission is the second of three flights launching components to complete the Japan Aerospace Exploration Agency's Kibo laboratory. The shuttle crew will install Kibo's large Japanese Pressurized Module and its remote manipulator system, or RMS. The 14-day flight includes three spacewalks. Launch is scheduled for 5:02 p.m. May 31. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. - After rollback of the rotating service structure (RSS) on Launch Pad 39B, Space Shuttle Discovery stands bathed in spotlights. Beneath the shuttle is the mobile launcher platform, which spans the flame trench below. The flame deflector system includes an inverted, V-shaped steel structure that receives and deflects the flames from the orbiter main engines on one side; the opposite side deflects the flames from the solid rocket boosters. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The sun rises on a cloudy Florida day to reveal Space Shuttle Atlantis awaiting launch atop a mobile launch platform at Launch Pad 39A. Rollback of the pad's rotating service structure, or RSS, is one of the milestones in preparation for the launch of mission STS-117 on June 8. Rollback started at 10:56 p.m. EDT June 7 and was complete at 11:34 p.m. The RSS, the massive structure to the left of the shuttle, provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 118th shuttle flight and the 21st U.S. flight to the International Space Station and will deliver and install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. -- Cameras are prepared to record the launch of Space Shuttle Atlantis from Launch Pad 39A following sunrise on a cloudy Florida day. Rollback of the pad's rotating service structure, or RSS, is one of the milestones in preparation for the launch of mission STS-117 on June 8. Rollback started at 10:56 p.m. EDT June 7 and was complete at 11:34 p.m. The RSS, the massive structure to the left of the shuttle, provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 118th shuttle flight and the 21st U.S. flight to the International Space Station and will deliver and install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. -- Space Shuttle Atlantis, mounted on a mobile launch platform, finally rests on the hard stand of Launch Pad 39A, straddling the flame trench. This is the second rollout for the shuttle. The flame trench transecting the pad's mound at ground level is 490 feet long, 58 feet wide and 40 feet high. It is made of concrete and refractory brick. Pad structures are insulated from the intense heat of launch by the flame deflector system, which protects the flame trench floor and the pad surface along the top of the flame trench. On the left of the shuttle are the fixed service structure and rotating service structure in open position. When closed, the rotating structure provides protected access to the orbiter for changeout and servicing of payloads at the pad. It is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The white area in the center is the Payload Changeout Room, an enclosed, environmentally controlled portion of the rotating service structure that supports payload delivery at the launch pad and subsequent vertical installation in the orbiter payload bay. First motion out of the Vehicle Assembly Building was at 5:02 a.m. EDT. In late February, while Atlantis was on the launch pad, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation, as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The shuttle was returned to the VAB for repairs. The launch of Space Shuttle Atlantis on mission STS-117 is now targeted for June 8. A flight readiness review will be held on May 30 and 31. Photo credit: NASA/Troy Cryder

KENNEDY SPACE CENTER, FLA. - In preparation for the July 1 launch of Space Shuttle Discovery on mission STS-121, the Launch Pad 39B rotating service structure (RSS) enclosing the shuttle rolls away. Above the golden external tank is the vent hood (known as the "beanie cap") at the end of the gaseous oxygen vent arm. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the space shuttle vehicle. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett

ISS038-E-023651 (26 Dec. 2013) --- Lake Sharpe near Lower Brule, South Dakota is featured in this image photographed by an Expedition 38 crew member on the International Space Station. The Missouri River rises in the Rocky Mountains of western Montana, and flows generally to the southeast for approximately 3,767 kilometers (2,341 miles) to its confluence with the Mississippi River north of St. Louis, Missouri -- making it the longest river in North America. The river does not follow a straight southeasterly course along this distance, but includes may meander bends such as illustrated in this photograph. This particular bend is occupied by Lake Sharpe, an approximately 130-kilometer (80 miles) long reservoir formed behind the Big Bend Dam on the Missouri River. The lake surface is frozen and covered with snow, presenting a uniform white appearance in the image. As meander bends develop, they tend to assume a distinctive U-shape when viewed from above. Over time, the river channel can continue to cut into the ends of the "U", eventually bringing them so close together that the river then cuts across the gap to achieve a shorter flow path, essentially short-circuiting or cutting off the meander bend. When this happens and the meander ceases to be part of the active river channel, it may become an oxbow lake. The distance across the narrow neck of land (lower right) associated with this meander near Lower Brule, South Dakota is approximately one kilometer (0.62 miles); however, as the river flow is controlled by the Big Bend Dam downstream, the natural process of meander cutoff has been significantly slowed. The snow cover also highlights circular agricultural fields on the small peninsula within the meander bend. This type of field indicates center-pivot irrigation, where water is distributed from a central point radially outwards using sprinklers to cover the field area. Crops grown here include corn and soybeans according to data from the US Department of Agriculture's CropScape database.

KENNEDY SPACE CENTER, FLA. - Against a dimming sky after sunset, lights on the structures on Launch Pad 39B cast a warm glow on Space Shuttle Discovery. The rotating service structure at left has been rolled back in preparation for launch July 1 on mission STS-121. Extending toward the cockpit of the shuttle is the orbiter access arm with the White Room extended. The White Room provides access into the orbiter for the astronauts. Above the golden external tank is the vent hood (known as the "beanie cap") at the end of the gaseous oxygen vent arm. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the space shuttle vehicle. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. The hinge column rests on the pad surface and is braced to the fixed service structure. Support for the outer end of the bridge is provided by two eight-wheel, motor-driven trucks that move along circular twin rails installed flush with the pad surface. The track crosses the flame trench on a permanent bridge. The RSS is 102 feet long, 50 feet wide and 130 feet high. The structure has orbiter access platforms at five levels to provide access to the payload bay while the orbiter is being serviced in the RSS. Each platform has independent extendable planks that can be arranged to conform to a payload's configuration. This mission is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. Photo credit: NASA/Kim Shiflett