
KENNEDY SPACE CENTER, FLA. -- Space Shuttle Columbia soars into the cloud-washed sky above Cape Canaveral Lighthouse. After six scrubs from the original Sept. 25 launch date, liftoff occurred Oct. 20 at 9:53 a.m. EDT. The crew of seven comprises Commander Ken Bowersox, Pilot Kent Rominger, Mission Specialists Kathy Thornton (Payload Commander), Catherine Coleman and Michael Lopez-Alegria, plus Payload Specialists Fred Leslie and Albert Sacco. The 72nd Shuttle mission, STS-73 marks the second flight of the U.S. Microgravity Laboratory. Research is being conducted in five areas: fluid physics, materials science, biotechnology, combustion science, and commercial space processing. The lighthouse, undergoing refurbishment and upgrade, is shown with a network of nylon lines ready for canvas panels to be attached. The canvas shroud will protect the surrounding area during sand-blasting of the lead-based paint.

Earth observations taken from shuttle Columbia during STS-73 mission. Views were taken using an electronic still camera.

KENNEDY SPACE CENTER, FLA. -- STS-73: Columbia

Astronaut Catherine G. Coleman, mission specialist for STS-73, works in the glovebox on the portside of the science module aboard the Space Shuttle Columbia in earth-orbit.

Albert Sacco Jr., payload specialist for STS-73, works in the glovebox on the portside of the science module aboard the Space Shuttle Columbia in earth orbit.
Onboard photo of space shuttle Columbia (STS-73) cargo bay payload - the United States Microgravity Laboratory-2 (USML-2) with an earthview.

A unique view of the Space Shuttle Columbia (STS-73) moments after bursting into Earth's atmosphere on its way toward space. Onboard the orbiter is the United States Microgravity Laboratory 2 (USML-2), a Marshall managed payload, where Columbia's seven member crew will perform experiments while in orbit.

Astronaut Kathryn C. Thornton, payload commander for STS-73, works at the drop physics module (DPM) on the portside of the science module aboard the Space Shuttle Columbia in Earth orbit.

S95-09157 (27 Apr. 1995) --- Payload specialist Fred W. Leslie has just translated from the top of a Shuttle mockup-trainer using a Sky-genie device during emergency egress training with his six STS-73 crew mates. He is assisted here by Scott Gill, a member of the STS-73 training staff. The seven will fly aboard the Space Shuttle Columbia later this year to support the United States Microgravity Laboratory (USML-2) mission.

S95-09153 (27 Apr. 1995) --- Astronaut Kenneth D. Bowersox has just translated from the top of a Shuttle mockup-trainer using a Sky-genie device during emergency egress training with his six STS-73 crew mates. He is assisted here by Scott Gill, a member of the STS-73 training staff. The seven will fly aboard the Space Shuttle Columbia later this year to support the United States Microgravity Laboratory (USML-2) mission.

Onboard Space Shuttle Columbia (STS-73) Payload Specialist Albert Sacco loads autoclaves using a power screwdriver into the Zeolite Crystal Growth (ZCG) experiment in the middeck for the United States Microgravity Laboratory 2 (USML-2) Spacelab mission.

Onboard photo of space shuttle Columbia (STS-73) crewmembers Fred Leslie (foreground) and Catherine Coleman aboard the United States Microgravity Laboratory (USML) conducting experiments in a microgravitational environment available in the Orbiter's cargo bay while in low earth orbit.

Onboard Space Shuttle Columbia (STS-73) Mission Specialists Catherine Cady Coleman works at the glovebox facility in support of the Protein Crystal Growth Glovebox (PCG-GBX) experiment in the United States Microgravity Laboratory 2 (USML-2) Spacelab science module.

Onboard Space Shuttle Columbia (STS-73) Payload Commander Kathryn Thornton and Commander Ken Bowersox discuss the Drop Physics Module (DPM) experiment in the United States Microgravity Laboratory 2 (USML-2) spacelab science module.

Onboard Space Shuttle Columbia (STS-73) Payload Commander Kathryn Thornton works with the Drop Physics Module (DPM) in the United States Microgravity Laboratory 2 (USML-2) Spacelab Science Module cleaning the experiment chamber of the DPM.

After completion of another United States Microgravity Laboratory (USML-2) mission, Space Shuttle Columbia (STS-73) and her seven member crew return to Earth on a clear November morning. Pictured is Columbia with her landing parachute deployed on final touchdown. Results from the mission's USML-2 will be sent to Marshall Space Flight Center who managed the mission.

A Great Blue Heron seems oblivious to the tremendous spectacle of light and sound generated by a Shuttle liftoff, as the Space Shuttle Columbia (STS-73) soars skyward from Launch Pad 39B. Columbia's seven member crew's mission included continuing experimentation in the Marshall managed payloads including the United States Microgravity Laboratory 2 (USML-2) and the keel-mounted accelerometer that characterizes the very low frequency acceleration environment of the orbiter payload bay during space flight, known as the Orbital Acceleration Research Experiment (OARE).

KENNEDY SPACE CENTER, FLA. - Astronaut Catherine “Cady” Coleman is interviewed in the NASA News Center at NASA Kennedy Space Center by a television reporter during launch activities for Return to Flight mission STS-114. Coleman has flown on two Shuttle missions, STS-73 and STS-93. More than a thousand media representatives from 36 states, the District of Columbia and 32 countries converged on the News Center for the historic launch.

STS073-E-5053 (26 Oct. 1995) --- Astronaut Kent V. Rominger, STS-73 pilot, floats through a tunnel connecting the space shuttle Columbia's cabin and its science module. Rominger is one of seven crewmembers in the midst of a 16-day multi-faceted mission aboard Columbia. For the next week and a half, the crew will continue working in shifts around the clock on a diverse assortment of United States Microgravity Laboratory (USML-2) experiments located in the science module. Fields of study include fluid physics, materials science, biotechnology, combustion science and commercial space processing technologies. The frame was exposed with an Electronic Still Camera (ESC).

STS073-232-013 (20 October - 5 November 1995) --- Astronaut Michael E. Lopez-Alegria, STS-73 mission specialist, checks notes related to the Commercial Generic Bioprocessing Apparatus (CGBA) aboard the Earth-orbiting Space Shuttle Columbia. CGBA supported over one hundred individual experiments on small quantities of samples ranging from molecules to small organisms. Lopez-Alegria joined four other NASA astronauts and two guest researchers for 16-days of United States Microgravity Laboratory 2 (USML-2) research aboard the Space Shuttle Columbia.

STS073-105-011 (20 October-5 November 1995) --- Astronaut Catherine G. Coleman, STS-73 mission specialist, settles in for a session of work at the glovebox on the starboard side of the United States Microgravity Laboratory (USML-2) module. Coleman was joined by four other NASA astronauts and two guest researchers for almost 16 days of research aboard the Space Shuttle Columbia in Earth-orbit.

STS073-E-5003 (23 Oct. 1995) --- Astronaut Kathryn C. Thornton, STS-73 payload commander, works at the Drop Physics Module (DPM) on the portside of the science module aboard the Space Shuttle Columbia in Earth orbit. Payload specialist Albert Sacco Jr. conducts an experiment at the Glovebox. This frame was exposed with the color Electronic Still Camera (ESC) assigned to the 16-day United States Microgravity Laboratory (USML-2) mission.

STS073-351-009 (20 October - 5 November 1995) --- Astronaut Kent V. Rominger, STS-73 pilot, retrieves a protein sample on the middeck of the Earth-orbiting Space Shuttle Columbia. Rominger, along with four other NASA astronauts and two guest researchers, spent 16 full days in space in support of the United States Microgravity Laboratory (USML-2) mission.

STS073-E-5000 (23 Oct. 1995) --- Astronaut Catherine G. Coleman, STS-73 mission specialist, works in the Glovebox on the portside of the science module aboard the space shuttle Columbia in Earth orbit. This Electronic Still Camera (ESC) frame was the first downlinked from the spacecraft during the scheduled 16-day United States Microgravity Laboratory (USML-2) mission.

S95-09132 (27 Apr. 1995) --- As he watches one his STS-73 crew mates rappel from the top of a ?troubled Shuttle,? astronaut Kenneth D. Bowersox, mission commander, prepares to participate in an emergency egress training session in the Johnson Space Center?s (JSC) Systems Integration Facility. Five astronauts and two payload specialists from the private sector will fly aboard the Space Shuttle Columbia later this year to support the United States Microgravity Laboratory (USML-2) mission.

STS073-356-029 (20 October - 5 November 1995) --- Astronaut Catherine G. Coleman, STS-73 mission specialist, checks out an Astroculture sample on the middeck of the Earth-orbiting Space Shuttle Columbia. Coleman was joined by four other NASA astronauts and two guest researchers for 16 full days of in-space research in support of the United States Microgravity Laboratory (USML-2) mission.

STS073-363-032 (20 October - 5 November 1995) --- Astronaut Kenneth D. Bowersox, STS-73 mission commander, studies the movement of fluids in microgravity at the Geophysical Fluid Flow Cell (GFFC) workstation in the science module of the Earth-orbiting Space Shuttle Columbia. Bowersox was joined by four other NASA astronauts and two guest researchers for almost 16-days of Earth-orbit research in support of the U.S. Microgravity Laboratory (USML-2) mission.

STS073-143-026 (20 October-5 November 1995) --- Astronaut Kathryn C. Thornton, STS-73 payload commander for the United States Microgravity Laboratory (USML-2), explores the inner workings of the Drop Physics Module (DPM). Thornton was joined by four other NASA astronauts and two guest researchers for almost 16 days of research aboard the Space Shuttle Columbia in Earth-orbit.

S95-09163 (27 Apr. 1995) --- Payload specialist Albert Sacco Jr. rappels from the top of a Shuttle mockup-trainer using a Sky-genie device during emergency egress training with his six STS-73 crew mates. The seven will fly aboard the Space Shuttle Columbia later this year to support the United States Microgravity Laboratory (USML-2) mission.

STS073-230-014 (20 October - 5 November 1995) --- Astronaut Kenneth D. Bowersox, STS-73 mission commander, uses a camcorder to record United States Microgravity Laboratory 2 (USML-2) activities onboard the Space Shuttle Columbia. Nearby, astronaut Kathryn C. Thornton, payload commander, prepares to open a supply chest to support one of many science experiments conducted by the seven-member crew during the 16-day USML-2 flight.

STS073-355-003 (20 October - 5 November 1995) --- Doing her version of "Look, Ma, no hands" is astronaut Catherine G. Coleman. The STS-73 mission specialist works out on the bicycle ergometer on the flight deck of the Earth-orbiting Space Shuttle Columbia. Coleman was one of five NASA astronauts who were joined by two guest researchers for 16 days of in-space research in support of the United States Microgravity Laboratory (USML-2) mission.

STS073-E-5024 (23 Oct. 1995)--- Albert Sacco Jr., STS-73 payload specialist, works in the Glovebox on the portside of the science module aboard the space shuttle Columbia in Earth orbit. This frame was exposed with the color Electronic Still Camera (ESC) assigned to the scheduled 16-day United States Microgravity Laboratory (USML-2) mission.

STS073-351-024 (20 October - 5 November 1995) --- Astronaut Kenneth D. Bowersox, STS-73 mission commander, retrieves a crow bar from a tool set onboard the science module in the cargo bay of the Earth-orbiting Space Shuttle Columbia. Various tools were available for a variety of in-flight maintenance tasks for the crew to carry out during the 16-day United States Microgravity Laboratory (USML-2) mission.

STS073-335-009 (20 October-5 November 1995) --- Astronaut Michael E. Lopez-Alegria, STS-73 mission specialist, changes the film in a 35mm camera on the flight deck of the Earth-orbiting Space Shuttle Columbia. Alegria joined four other NASA astronauts and two guest researchers for almost 16-days of Earth-orbit research in support of the U.S. Microgravity Laboratory (USML-2) mission.

STS073-352-008 (20 October - 5 November 1995) --- On the middeck of the Earth-orbiting Space Shuttle Columbia, astronaut Kent V. Rominger, STS-73 pilot, retrieves gear necessary for sampling of the air. In addition to his pilot duties and the performance of tasks in support of the U.S. Microgravity Laboratory (USML-2) mission, Rominger and other crew members pitched in with housekeeping chores as part of their 16-days of Earth-orbit activity.

STS073-E-5081 (30 Oct. 1995) --- The port of the Queen Mary ocean liner is near bottom right center in this Electronic Still Camera (ESC) view. The scene covers from Redondo Beach on the left to Seal Beach on the right; from San Pedro at bottom to the Torrance-Gardena area at top.

STS073-E-5099 (30 Oct. 1995) --- The entire coast of Massachusetts can be seen, from Martha's Vineyard and Buzzard's Bay in the foreground past the Boston metropolitan region. The frame was exposed with the Electronic Still Camera (ESC).

STS073-E-5082 (30 Oct. 1995) --- The United States Naval Air Station at San Diego is near left center in this Electronic Still Camera (ESC) view. Also seen are the nearby United States Naval Reservation and the Coronado Amphibious Base. The United States - Mexico border is just out of view at bottom right edge of the frame.

STS073-E-5098 (30 Oct. 1995) --- Long Island, New York stretches across the scene. The New York City metropolitan complex is at the left; Central Park can be seen as a dark rectangle between the Hudson and East Rivers. Sandy beaches of the Long Island barrier islands mark the boundary between Atlantic Ocean and quiet lagoons and marshes. The frame was exposed with the Electronic Still Camera (ESC).

STS073-E-5091 (30 Oct. 1995) --- The Mississippi River meanders through its floodplain between the northeastern corner of Arkansas and the northwestern corner of Tennessee. Blytheville, Arkansas and the former Eaker Air Force Base can be seen near the top of the image. The frame was exposed with the Electronic Still Camera (ESC).

STS073-E-5096 (30 Oct. 1995) --- Central Chesapeake Bay. The lower Potomac River and Patuxent River join the Bay, whose eastern side is muddy from sediment eroded from the shoreline. The image is centered on the Patuxent River Naval Air Station. The frame was exposed with the Electronic Still Camera (ESC).

STS073-E-5071 (30 Oct. 1995) --- The Dallas-Ft. Worth metroplex is featured in this vertical view provided by an Electronic Still Camera (ESC) aboard the Earth-orbiting space shuttle Columbia. The area covers a range from Lake Benbrook on the left to Rockwall County (the state's smallest of 254 counties) on the right; and from a point just above Waxahachie on the south to Carrollton, north.

STS073-229-014 (20 October - 5 November 1995) --- Astronauts Kathryn C. Thornton, STS-73 payload commander, and Kenneth D. Bowersox, mission commander, observe a liquid drop's activity at the Drop Physics Module (DPM) in the science module aboard the Earth-orbiting Space Shuttle Columbia. The drop is partially visible at the center of the left edge of the frame. The two were joined by three other NASA astronauts and two guest researchers for almost 16-days of in-orbit research in support of the U.S. Microgravity Laboratory (USML-2) mission.

S92-46167 (16-20 Aug. 1992) --- Michael E. Lopez-Alegria, one of 19 astronaut candidates announced in March, fashions a shelter from wood and parachute material. He was taking in a four-day wilderness survival training course at Fairchild Air Force Base in Washington. Lopez-Alegria and his class mates had reported to the Johnson Space Center (JSC) in Houston, Texas, for initial training and evaluation earlier this month. EDITOR?S NOTE: Lopez-Alegria has been named fly aboard the Space Shuttle Columbia for the STS-73 mission, scheduled for 1995

STS073-233-032 (20 October - 5 November 1995) --- Astronaut Michael E. Lopez-Alegria (left), STS-73 mission specialist, assists payload specialist Fred W. Leslie in an in-flight maintenance task involving the Fiber Support Droplet Combustion (FSDC) experiment. This new Glovebox investigation tests a technique for studying combustion in the weightless environment of space. The two joined five other crew members onboard the Space Shuttle Columbia for 16 days of in-space research in support of the United States Microgravity Laboratory (USML-2) mission.

STS073-131-014 (20 October-5 November 1995) --- Astronaut Kent V. Rominger, STS-73 pilot, uses a camcorder to record progress in the Hand-Held Diffusion Test Cell (HHDTC) experiment. This test dealt with crystal growth by liquid-to-liquid diffusion. Four HHDTC units containing four test cells each produced protein crystals by diffusing one liquid to another. Rominger joined four other NASA astronauts and two guest researchers for 16 days of in-space United States Microgravity Laboratory 2 (USML-2) research aboard the Space Shuttle Columbia.

STS073-E-5041 (26 Oct. 1995) --- Fred W. Leslie, STS-73 payload specialist, working out of NASA's Marshall Space Flight Center (MSFC), in Alabama, grabs a support bar on a science workstation rack after floating from the space shuttle Columbia's cabin into the science module. Leslie is one of seven crewmembers in the midst of a 16-day multi-faceted mission aboard Columbia. For the next week and a half, Leslie and the rest of the crew will continue working in shifts around the clock on a diverse assortment of United States Microgravity Laboratory (USML-2) experiments located in the science module. Fields of study include fluid physics, materials science, biotechnology, combustion science and commercial space processing technologies. The frame was exposed with an Electronic Still Camera (ESC).

These five astronauts and two United States Microgravity Laboratory (USML) payload specialists pause from a rigid training schedule for the STS-73 crew portrait. On the front row, left to right, are Albert Sacco Jr., payload specialist; Kent V. Rominger, pilot; and Michael E. Lopez-Alegria, mission specialist. On the back row are, left to right, Catherine G. Coleman, mission specialist; Kenneth D. Bowersox, commander; Fred W. Leslie, payload specialist; and Kathryn C. Thornton, payload commander. The STS-073 crew launched aboard the Space Shuttle Columbia on October 20, 1995 at 9:53:00.069 am (EDT). The mission served as the second flight of the Microgravity Laboratory (USML-2).

CAPE CANAVERAL, Fla. -- This is a version of space shuttle Challenger's orbiter tribute, or OV-099, which hangs in Firing Room 4 of the Launch Control Center at NASA's Kennedy Space Center in Florida. Challenger's accomplishments include the first night launch and first African-American in space, Guion Bluford, on STS-8, the first in-flight capture, repair and redeployment of an orbiting satellite during STS-41C, the first American woman in space, Sally Ride, on STS-7, and the first American woman to walk in space, Kathryn Sullivan, during STS-41G. Challenger is credited with blazing a trail for NASA's other orbiters with the first night landing at Edwards Air Force Base in California on STS-8 and the first landing at Kennedy on STS-41B. The spacewalker in the tribute represents Challenger’s role in the first spacewalk during STS-6 and the first untethered spacewalk on STS-41B. Crew-designed patches for each of Challenger’s missions lead from Earth toward a remembrance of the STS-51L crew, which was lost 73 seconds after liftoff on Jan. 28, 1986. Five orbiter tributes are on display in the firing room, representing Atlantis, Challenger, Columbia, Endeavour and Discovery. Graphic design credit: NASA/Lynda Brammer. NASA publication number: SP-2010-08-162-KSC

CAPE CANAVERAL, Fla. -- This is a printable version of space shuttle Challenger's orbiter tribute, or OV-099, which hangs in Firing Room 4 of the Launch Control Center at NASA's Kennedy Space Center in Florida. Challenger's accomplishments include the first night launch and first African-American in space, Guion Bluford, on STS-8, the first in-flight capture, repair and redeployment of an orbiting satellite during STS-41C, the first American woman in space, Sally Ride, on STS-7, and the first American woman to walk in space, Kathryn Sullivan, during STS-41G. Challenger is credited with blazing a trail for NASA's other orbiters with the first night landing at Edwards Air Force Base in California on STS-8 and the first landing at Kennedy on STS-41B. The spacewalker in the tribute represents Challenger’s role in the first spacewalk during STS-6 and the first untethered spacewalk on STS-41B. Crew-designed patches for each of Challenger’s missions lead from Earth toward a remembrance of the STS-51L crew, which was lost 73 seconds after liftoff on Jan. 28, 1986. Five orbiter tributes are on display in the firing room, representing Atlantis, Challenger, Columbia, Endeavour and Discovery. Graphic design credit: NASA/Lynda Brammer. NASA publication number: SP-2010-08-162-KSC

CAPE CANAVERAL, Fla. -- This orbiter tribute of space shuttle Challenger, or OV-099, hangs in Firing Room 4 of the Launch Control Center at NASA's Kennedy Space Center in Florida. Challenger's accomplishments include the first night launch and first African-American in space, Guion Bluford, on STS-8, the first in-flight capture, repair and redeployment of an orbiting satellite during STS-41C, the first American woman in space, Sally Ride, on STS-7, and the first American woman to walk in space, Kathryn Sullivan, during STS-41G. Challenger is credited with blazing a trail for NASA's other orbiters with the first night landing at Edwards Air Force Base in California on STS-8 and the first landing at Kennedy on STS-41B. The spacewalker in the tribute represents Challenger’s role in the first spacewalk during STS-6 and the first untethered spacewalk on STS-41B. Crew-designed patches for each of Challenger’s missions lead from Earth toward a remembrance of the STS-51L crew, which was lost 73 seconds after liftoff on Jan. 28, 1986. Five orbiter tributes are on display in the firing room, representing Atlantis, Challenger, Columbia, Endeavour and Discovery. Graphic design credit: NASA/Lynda Brammer

The crew patch of STS-73, the second flight of the United States Microgravity Laboratory (USML-2), depicts the Space Shuttle Columbia in the vastness of space. In the foreground are the classic regular polyhedrons that were investigated by Plato and later Euclid. The Pythagoreans were also fascinated by the symmetrical three-dimensional objects whose sides are the same regular polygon. The tetrahedron, the cube, the octahedron, and the icosahedron were each associated with the Natural Elements of that time: fire (on this mission represented as combustion science); Earth (crystallography), air and water (fluid physics). An additional icon shown as the infinity symbol was added to further convey the discipline of fluid mechanics. The shape of the emblem represents a fifth polyhedron, a dodecahedron, which the Pythagoreans thought corresponded to a fifth element that represented the cosmos.

KENNEDY SPACE CENTER, FLA. -- A new Enhanced Main Events Controller (E-MEC) for Shuttle Endeavour sits on a table in a Quality trailer in the Launch Pad 39B area. The original E-MEC in Endeavour became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. The E-MECs are located in the orbiter's aft compartment and both are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants must be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 39A, workers move the replacement Enhanced Main Events Controller (E-MEC) into Shuttle Endeavour's aft compartment in the payload bay. The original E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Workers in a Quality trailer in the Launch Pad 39B Area unwrap a new Enhanced Main Events Controller (E-MEC) to be installed in Shuttle Endeavour. The original E-MEC in Endeavour became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. The E-MECs are located in the orbiter's aft compartment and both are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants must be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Technicians remove a faulty Enhanced Main Events Controller (E-MEC) from Shuttle Endeavour at Launch Pad 39A. The E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Workers in a Quality trailer in the Launch Pad 39B Area unwrap a new Enhanced Main Events Controller (E-MEC) to be installed in Shuttle Endeavour. The original E-MEC in Endeavour became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. The E-MECs are located in the orbiter's aft compartment and both are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants must be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Workers carry away the faulty Enhanced Main Events Controller (E-MEC) from Shuttle Endeavour at Launch Pad 39A. The E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- A new Enhanced Main Events Controller (E-MEC) for Shuttle Endeavour sits on a table in a Quality trailer in the Launch Pad 39B area. The original E-MEC in Endeavour became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. The E-MECs are located in the orbiter's aft compartment and both are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants must be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Workers carry the replacement Enhanced Main Events Controller (E-MEC) to Shuttle Endeavour at Launch Pad 39A for installation in the aft compartment of the payload bay. The original E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Technicians work in the aft compartment of Shuttle Endeavour's payload bay, where a new Enhanced Main Events Controller (E-MEC) will be installed. The original E-MEC in Endeavour became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants had to be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Technicians remove a faulty Enhanced Main Events Controller (E-MEC) from Shuttle Endeavour at Launch Pad 39A. The E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Workers carry away the faulty Enhanced Main Events Controller (E-MEC) from Shuttle Endeavour at Launch Pad 39A. The E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Workers carry the replacement Enhanced Main Events Controller (E-MEC) to Shuttle Endeavour at Launch Pad 39A for installation in the aft compartment of the payload bay. The original E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- Technicians work in the aft compartment of Shuttle Endeavour's payload bay, where a new Enhanced Main Events Controller (E-MEC) will be installed. The original E-MEC in Endeavour became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. Before workers can begin E-MEC replacement efforts at the launch pad, cryogenic reactants had to be offloaded from the orbiter and Space Shuttle ordnance disconnected. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 39A, workers move the replacement Enhanced Main Events Controller (E-MEC) into Shuttle Endeavour's aft compartment in the payload bay. The original E-MEC became suspect during the Jan. 31 launch countdown and mission STS-99 was delayed when NASA managers decided to replace it. Each Shuttle carries two enhanced master events controllers (E-MECs), which provide relays for onboard flight computers to send signals to arm and fire pyrotechnics that separate the solid rockets and external tank during assent. Both E-MECs are needed for the Shuttle to be cleared for flight. Currently Endeavour and Columbia are the only two orbiters with the E-MECs. Built by Rockwell's Satellite Space Electronics Division, Anaheim, Calif., each unit weighs 65 pounds and is approximately 20 inches long, 13 inches wide and 8 inches tall. Previously, three Shuttle flights have been scrubbed or delayed due to faulty MECs: STS-73, STS-49 and STS-41-D. The next scheduled date for launch of STS-99 is Feb. 11 at 12:30 p.m. EST

STS073-708-089 (26 October 1995) --- As evidenced by this 70mm photograph from the Earth-orbiting Space Shuttle Columbia, international borders have become easier to see from space in recent decades. This, according to NASA scientists studying the STS-73 photo collection, is particularly true in arid and semi-arid environments. The scientists go on to cite this example of the razor-sharp vegetation boundary between southern Israel and Gaza and the Sinai. The nomadic grazing practices to the south (the lighter areas of the Sinai and Gaza, top left) have removed most of the vegetation from the desert surface. On the north side of the border, Israel uses advanced irrigation techniques in Israel, mainly "trickle irrigation" by which small amounts of water are delivered directly to plant roots. These water-saving techniques have allowed precious supplies from the Jordan River to be used on farms throughout the country. Numerous fields of dark green can be seen in this detailed view. Scientists say this redistribution of the Jordan River waters has increased the Israeli vegetation cover to densities that approach those that may have been common throughout the Mid-East in wetter early Biblical times. A small portion of the Mediterranean Sea appears top right.

STS073-S-001 (May 1995) --- The crew patch of STS-73, the second flight of the United States Microgravity Laboratory (USML-2), depicts the space shuttle Columbia in the vastness of space. In the foreground are the classic regular polyhedrons that were investigated by Plato and later Euclid. The Pythagoreans were also fascinated by the symmetrical three-dimensional objects whose sides are the same regular polygon. The tetrahedron, the cube, the octahedron, and the icosahedron were each associated with the "Natural Elements" of that time: fire (on this mission represented as combustion science); Earth (crystallography), air and water (fluid physics). An additional icon shown as the infinity symbol was added to further convey the discipline of fluid mechanics. The shape of the emblem represents a fifth polyhedron, a dodecahedron, which the Pythagoreans thought corresponded to a fifth element that represented the cosmos. 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