S63-21624 (November 1963) --- Main instrument panel for the Mercury spacecraft. Photo credit: NASA

S61-01928 (5 May 1961) --- Mercury-Redstone 3 (MR-3), the United States' first manned spaceflight, is launched from Cape Canaveral on a suborbital mission. Astronaut Alan B. Shepard Jr. was the pilot of the Mercury spacecraft, designated "Freedom 7". The spacecraft attained a maximum speed of 5,180 miles per hour (mph), reached an altitude of 116 1/2 statute miles, and landed 302 statute miles downrange from Cape Canaveral, Florida. Photo credit: NASA or National Aeronautics and Space Administration

S63-18867 (October 1963) --- Mercury spacecraft with measurements and cutaway view. Photo credit: NASA

S61-02821 (21 July 1961) --- Attempted recovery of Mercury spacecraft at end of the Mercury-Redstone 4 (MR-4) mission. View shows the Marine helicopter dropping a recovery line to the capsule. In the upper left corner of the view, the recovery ship and another helicopter can be seen. Photo credit: NASA

S67-19582 (1961) --- View of the reconstructed Mercury-Atlas 1 (MA-1) spacecraft. The capsule exploded one minute after launch and the debris was reassembled for study. Photo credit: NASA

In this undated photograph, Dr. von Braun is shown during a visit to McDonnell Aircraft to inspect Mercury spacecraft manufacturing.

S61-03257 (1961) --- View of Mercury spacecraft instrument control panels. Photo credit: NASA

S61-02820 (21 July 1961) --- Attempted recovery of Mercury spacecraft at end of the Mercury-Redstone 4 (MR-4) mission. View shows the Marine helicopter pulled almost to the waters surface by the weight of the capsule, which filled with water. It eventually had to abandon its recovery attempts. Behind the Marine helicopter, a Navy helicopter prepares to assist. Photo credit: NASA

S62-00371 (20 Feb. 1962) --- Mercury astronaut John H. Glenn Jr., pilot of the Mercury-Atlas 6 (MA-6) spaceflight, enters the Mercury "Friendship 7" spacecraft during the MA-6 prelaunch preparations at Cape Canaveral, Florida. Glenn became the first American to orbit Earth. Photo credit: NASA

S61-02921 (21 July 1961) --- Attempted recovery of Mercury spacecraft at end of the Mercury-Redstone 4 (MR-4) mission. View shows the top of the capsule before it sinks beneath the waves. Photo credit: NASA

S64-14854 (20 Feb. 1962) --- Astronaut John H. Glenn Jr. and technicians inspect a decal ready for application to the side of his Mercury spacecraft prior to launch on Feb. 20, 1962. The decal reads "Friendship 7". Photo credit: NASA

G61-00030 (4 Nov. 1959) --- Launch of Little Joe-2 from Wallops Island carrying Mercury spacecraft test article. The suborbital test flight of the Mercury capsule was to test the escape system. Vehicle functioned perfectly, but escape rocket ignited several seconds too late. Photo credit: NASA

S64-14861 (1962) --- Department of Defense (DOD) recovery personnel and spacecraft technicians from NASA and McDonnell Aircraft Corp., inspect astronaut John Glenn's Mercury spacecraft, Friendship 7, following its return to Cape Canaveral after recovery in the Atlantic Ocean. Photo credit: NASA

A close-up of the Mercury Laser Altimeter MLA profile of Mercury acquired during NASA MESSENGER spacecraft first Mercury flyby on January 14, 2008.

S61-02826 (21 July 1961) --- A U.S. Marine Corps helicopter attempts an unsuccessful recovery of the Mercury-Redstone 4 "Liberty Bell 7" spacecraft. The spacecraft hatch opened prematurely, and astronaut Virgil I. Grissom, pilot, escaped into the water. The helicopter hooked onto the spacecraft but could not retrieve it. Grissom was recovered by another helicopter and flown to the recovery ship, USS Randolph. The Mercury spacecraft sank to the bottom of the ocean. Photo credit: NASA

S61-02824 (21 July 1961) --- A U.S. Marine Corps helicopter attempts an unsuccessful recovery of the Mercury-Redstone 4 "Liberty Bell 7" spacecraft. The spacecraft hatch opened prematurely, and astronaut Virgil I. Grissom, pilot, escaped into the water. The helicopter hooked onto the spacecraft but could not retrieve it. Grissom was recovered by another helicopter and flown to the recovery ship, USS Randolph. The Mercury spacecraft sank to the bottom of the ocean. Photo credit: NASA

S61-02817 (21 July 1961) --- Attempted recovery of Mercury spacecraft at end of the Mercury-Redstone 4 (MR-4) mission. View shows the Marine helicopter pulled almost to the waters surface by the weight of the capsule, which filled with water. Behind the Marine helicopter, a Navy helicopter prepares to assist. Photo credit: NASA

S63-03960 (1 Feb. 1963) --- Astronaut L. Gordon Cooper Jr., prime pilot for the Mercury-Atlas 9 (MA-9) mission, checks over the instrument panel from Mercury spacecraft #20 with Robert Graham, McDonnell Aircraft Corp. spacecraft engineer. It contains the instruments necessary to monitor spacecraft systems and sequencing, the controls required to initiate primary sequences manually, and flight control displays. Photo credit: NASA

S62-00955 (February 1962) --- This is a view of John H. Glenn Jr. ingressing the Mercury-Atlas 6 spacecraft. Photo credit: NASA

Artist impression of NASA MErcury Surface, Space ENvironment, GEochemistry, and Ranging MESSENGER spacecraft in orbit at Mercury.

On January 14, 2008, NASA MESSENGER spacecraft Mercury Laser Altimeter MLA became the first instrument to measure the distance between a spacecraft and the surface of Mercury.

NASA Mariner 10 spacecraft was coaxed into a third and final encounter with Mercury in March of 1975. This is one of the highest resolution images of Mercury acquired by the spacecraft.

S62-00957 (20 Feb. 1962) --- Project Mercury astronaut John H. Glenn Jr., enters the Friendship 7 spacecraft during the last part of the countdown on Feb. 20, 1962. At 9:47 a.m. (EST), the Atlas launch vehicle lifted the spacecraft into orbit for a three-orbit mission lasting four hours, 55 minutes and 23 seconds. Glenn and his spacecraft were recovered by the destroyer Noa just 21 minutes after landing in the Atlantic near Grand Turk Island, to successfully complete the nation's first manned orbital flight. Photo credit: NASA

S88-31376 (5 May 1961) --- Astronaut Alan B. Shepard Jr., pilot of the Mercury-Redstone 3 (MR-3) suborbital spaceflight, is retrieved by a helicopter from the USS Lake Champlain during recovery operations in the western Atlantic Ocean. Shepard and the Mercury spacecraft designated the ?Freedom 7? (floating in water below) were flown to the deck of the recovery ship within 11 minutes of splashdown. MR-3 was the United States? first manned space mission. The spacecraft attained a maximum speed of 5,180 miles per hour, reached an altitude of 116 1/2 statute miles, and landed 302 statute miles downrange from Cape Canaveral, Florida. The suborbital mission lasted 15 minutes and 22 seconds. Photo credit: NASA or National Aeronautics and Space Administration

On January 14, 2008, NASA MESSENGER spacecraft passed 200 kilometers 124 miles above the surface of Mercury and snapped the first pictures of a side of Mercury not previously seen, with a view looking toward Mercury south pole.

After passing Mercury the first time and making a trip around the Sun, NASA Mariner 10 again flew by Mercury on Sept. 21, 1974. This encounter brought the spacecraft in front of Mercury in the southern hemisphere.

After passing Mercury the first time and making a trip around the Sun, NASA Mariner 10 again flew by Mercury on Sept. 21, 1974. This encounter brought the spacecraft in front of Mercury in the southern hemisphere.

As NASA MESSENGER spacecraft sped by Mercury on January 14, 2008, the Narrow Angle Camera NAC of the Mercury Dual Imaging System MDIS captured this shot looking toward Mercury north pole.

S62-00941 (20 Feb. 1962) --- The Mercury-Atlas 6 (MA-6) "Friendship 7" spacecraft is retrieved from the Atlantic Ocean following astronaut John H. Glenn Jr.'s three-orbit space mission. In this view, the capsule is still in the water, with retrieval cable connected to it. Photo credit: NASA

This spectacular color mosaic shows the eastern limb of Mercury as seen by NASA MESSENGER as the spacecraft departed the planet following the mission first Mercury flyby in January 2008.

With just two days until NASA MESSENGER spacecraft closest pass by Mercury, the Mercury Dual Imaging System MDIS is acquiring sets of images twice a day.

S63-03975 (1963) --- Astronaut L. Gordon Cooper Jr., prime pilot for the Mercury-Atlas 9 (MA-9) mission, is pictured prior to entering the Mercury spacecraft for a series of simulated flight tests. During these tests NASA doctors, engineers and technicians monitor Cooper's performance. Photo credit: NASA

This scene was imaged by NASA MESSENGER spacecraft Narrow Angle Camera NAC on the Mercury Dual Imaging System MDIS during the spacecraft flyby of Mercury on January 14, 2008.

NASA Mariner 10 spacecraft was coaxed into a third and final encounter with Mercury in March of 1975. This is one of the highest resolution images of Mercury acquired by the spacecraft. The prominent scarp snaking up the image was named Discovery Rupes.

As NASA MESSENGER spacecraft drew closer to Mercury for its historic first flyby, the spacecraft Narrow Angle Camera NAC on the Mercury Dual Imaging System MDIS acquired an image mosaic of the sunlit portion of the planet.

S71-24944 (16 May 1963) --- The Mercury-Atlas 9 "Faith 7" spacecraft, with astronaut L. Gordon Cooper Jr. aboard, splashes down in the Pacific Ocean to conclude a 22-orbit mission lasting 34 hours and 20.5 minutes. The capsule's parachute is fully deployed in this view. A rescue helicopter hovers overhead. Photo credit: NASA

With just one day until NASA MESSENGER spacecraft historic flyby of Mercury, MESSENGER has Mercury clearly in its sights. The Narrow Angle Camera, part of the Mercury Dual Imaging System MDIS, took this image on January 12, 2008.

NASA MESSENGER spacecraft Narrow Angle Camera NAC on the Mercury Dual Imaging System MDIS acquired this view of Mercury surface illuminated obliquely from the right by the Sun.

An artist rendering of the MESSENGER spacecraft is shown passing near the crater Hokusai and its extensive system of rays. Both the monochrome and enhanced color views of Mercury were obtained during MESSENGER second Mercury flyby.

As NASA MESSENGER neared Mercury on January 14, 2008, the spacecraft Wide Angle Camera on the Mercury Dual Imaging System MDIS took this image of the planet full crescent.

A cratered area near Mercury South Pole was photographed by NASA Mariner 10 during its second flyby of the planet of Sept. 21, 1974 the spacecraft made its first encounter with Mercury on March 19, 1974.

After NASA MESSENGER spacecraft completed its successful flyby of Mercury, the Narrow Angle Camera NAC, part of the Mercury Dual Imaging System MDIS, took these images of the receding planet. This is a frame from an animation.

As NASA MESSENGER approached Mercury on January 14, 2008, the spacecraft Narrow-Angle Camera on the Mercury Dual Imaging System MDIS instrument captured this view of the planet rugged, cratered landscape illuminated obliquely by the Sun.

As NASA MESSENGER spacecraft approached Mercury on Jnuary 14, 2008, the Narrow Angle Camera NAC of the Mercury Dual Imaging System MDIS snapped this image of the crater Matisse.

This high-resolution NAC image shows a view of Mercury dawn terminator, the division between the sunlit dayside and dark nightside of the planet, as seen as the MESSENGER spacecraft departed the planet during the mission second Mercury flyby.

On January 13, 2008, beginning 30 hours before NASA MESSENGER spacecraft closest approach to Mercury, the Wide Angle Camera, part of the Mercury Dual Imaging System MDIS, began snapping images as it approached the planet.

During NASA MESSENGER spacecraft flyby of Mercury on January 14, 2008, part of the planned sequence of observations included taking images of the same portion of Mercury surface from five different viewing angles.

After NASA MESSENGER spacecraft completed its successful flyby of Mercury, the Narrow Angle Camera NAC, part of the Mercury Dual Imaging System MDIS, took these images of the receding planet.

This photograph of Mercury was taken by NASA Mariner 10 spacecraft shows smooth plains areas on Mercury that are thought to be volcanic in origin with lava flows filling in heavily cratered areas.

Calcium was detected in the near-Mercury exosphere by NASA MESSENGER spacecraft and has also been observed telescopically from Earth.

Watchers of the Wall. This image from NASA MESSENGER spacecraft features the sharp rim of an unnamed complex crater on Mercury.

This frame from an animation shows a conceptual sketch of Mercury magnetosphere at the time of NASA MESSENGER spacecraft flyby.

NASA MESSENGER spacecraft continued to speed toward Mercury, preparing for its closest approach to the planet on Monday, January 14, 2008.

This is one of the earliest images of Mercury returned by NASA's MESSENGER spacecraft. It was taken in January 2008. http://photojournal.jpl.nasa.gov/catalog/PIA19269

This image, from NASA Mariner 10 spacecraft which launched in 1974, is of the southern hemisphere of Mercury.

This image, from NASA Mariner 10 spacecraft which launched in 1974, is of the northern half of Mercury Shakespeare Quadrangle. http://photojournal.jpl.nasa.gov/catalog/PIA00066

Mercury northern region is dominated by expansive smooth plains, created by huge amounts of volcanic material flooding across Mercury surface in the past, as seen by NASA MESSENGER spacecraft. The volcanic lava flows buried craters, leaving only traces of their rims visible. Such craters are called ghost craters, and there are many visible in this image, including a large one near the center. Wrinkle ridges cross this scene and small troughs are visible regionally within ghost craters, formed as a result of the lava cooling. The northern plains are often described as smooth since their surface has fewer impact craters and thus has been less battered by such events. This indicates that these volcanic plains are younger than Mercury's rougher surfaces. Instrument: Mercury Dual Imaging System (MDIS) Center Latitude: 60.31° N Center Longitude: 36.87° E Scale: The large ghost crater at the center of the image is approximately 103 kilometers (64 miles) in diameter http://photojournal.jpl.nasa.gov/catalog/PIA19415

As NASA MESSENGER spacecraft approached Mercury for its first flyby, the Narrow Angle Camera, part of the Mercury Dual Imaging System MDIS instrument acquired the nine images shown here taken from January 9 to 13, 2008.

NASA Mercury-bound MESSENGER spacecraft captured several stunning images of Earth during a gravity assist swingby of its home planet on Aug. 2, 2005.

NASA Mariner 10 took this picture of the densely cratered surface of Mercury when the spacecraft was 18,200 kilometers 8085 miles from the planet on March 29, 1974.

NASA Mercury-bound MESSENGER spacecraft captured several stunning images of Earth during a gravity assist swingby of its home planet on Aug. 2, 2005.

During its flyby of Mercury, NASA MESSENGER spacecraft acquired high-resolution images of the planet surface. This image was obtained on January 14, 2008.

On January 14, 2008, NASA MESSENGER became the first spacecraft to see the side of Mercury shown in this image -- the historic first look at the previously unseen side.

On January 14, 2008, NASA MESSENGER flew by Mercury and snapped images of a large portion of the surface that had not been previously seen by spacecraft including numerous craters.

Shortly following NASA MESSENGER spacecraft closest approach to Mercury on January 14, 2008, the spacecraft Narrow Angle Camera NAC instrument acquired this image as part of a mosaic that covers much of the sunlit portion of the hemisphere.

This image, from NASA Mariner 10 spacecraft which launched in 1974, is of the H-7 Beethoven Quadrangle, and lies in Mercury Equatorial Mercator. NASA Mariner 10 spacecraft imaged the region during its initial flyby of the planet.

NASA MESSENGER Earth flyby on Aug. 2, 2005, not only adjusted the spacecraft path to Mercury - the gravity assist maneuver allowed the spacecraft team to test several MESSENGER science instruments by observing its home planet.

During the first year of NASA MESSENGER orbital mission, the spacecraft GRS instrument measured the elemental composition of Mercury surface materials. mong the most important discoveries from the GRS was the observation of higher abundances of the moderately volatile elements potassium, sodium, and chlorine than expected from previous scientific models and theories. Particularly high concentrations of these elements were observed at high northern latitudes, as illustrated in this potassium abundance map, which provides a view of the surface centered at 60° N latitude and 120° E longitude. This map was the first elemental map ever made of Mercury's surface and is to-date the only map to report absolute elemental concentrations, in comparison to element ratios. Prior to MESSENGER's arrival at Mercury, scientists expected that the planet would be depleted in moderately volatile elements, as is the case for our Moon. The unexpectedly high abundances observed with the GRS have forced a reevaluation of our understanding of the formation and evolution of Mercury. In addition, the K map provided the first evidence for distinct geochemical terranes on Mercury, as the high-potassium region was later found to also be distinct in its low Mg/Si, Ca/Si, S/Si, and high Na/Si and Cl/Si abundances. Instrument: Gamma-Ray Spectrometer (GRS) http://photojournal.jpl.nasa.gov/catalog/PIA19414

As the MESSENGER spacecraft approached Mercury, the UVVS field of view was scanned across the planet's exospheric "tail," which is produced by the solar wind pushing Mercury's exosphere (the planet's extremely thin atmosphere) outward. This figure, recently published in Science magazine, shows a map of the distribution of sodium atoms as they stream away from the planet (see PIA10396); red and yellow colors represent a higher abundance of sodium than darker shades of blue and purple, as shown in the colored scale bar, which gives the brightness intensity in units of kiloRayleighs. The escaping atoms eventually form a comet-like tail that extends in the direction opposite that of the Sun for many planetary radii. The small squares outlined in black correspond to individual measurements that were used to create the full map. These measurements are the highest-spatial-resolution observations ever made of Mercury's tail. In less than six weeks, on October 6, 2008, similar measurements will be made during MESSENGER's second flyby of Mercury. Comparing the measurements from the two flybys will provide an unprecedented look at how Mercury's dynamic exosphere and tail vary with time. Date Acquired: January 14, 2008. http://photojournal.jpl.nasa.gov/catalog/PIA11076

In this perspective view, NASA MESSENGER spacecraft looked northwest over the Caloris Basin, a depression about 1500 km in diameter formed several billion years ago by the impact of a large projectile into the surface of Mercury. The mountain range at the edge of the basin can be seen as an arc in the background. In the foreground, we see a set of tectonic troughs, known as Pantheon Fossae, radiating from the center of the basin outward toward the edge of the basin interior. A 41-km-diameter impact crater, Apollodorus, is superposed just slightly off from the center of Pantheon Fossae. White and red are high topography, and greens and blues are low topography, with a total height differences of roughly 4 km. The MESSENGER spacecraft was launched in 2004 and ended it's orbital operations yesterday, April 30, 2015, by impacting Mercury's surface. Background image texture is provided by the Mercury Dual Imaging System (MDIS) instrument while color corresponds to surface elevation data obtained from the Mercury Laser Altimeter (MLA) experiment, with both draped over a digital elevation model derived from MLA altimetric data. Instrument: Mercury Dual Imaging System (MDIS) and Mercury Laser Altimeter (MLA) Approximate Center Latitude: 33.7° N Approximate Center Longitude: 158.7° E Scale: Apollodorus crater is approximately 41 km (25 miles) in diameter http://photojournal.jpl.nasa.gov/catalog/PIA19450

The MASCS instrument onboard NASA MESSENGER spacecraft was designed to study both the exosphere and surface of Mercury. To learn more about the minerals and surface processes on Mercury, the Visual and Infrared Spectrometer (VIRS) portion of MASCS has been diligently collecting single tracks of spectral surface measurements since MESSENGER entered orbit. The track coverage is now extensive enough that the spectral properties of both broad terrains and small, distinct features such as pyroclastic vents and fresh craters can be studied. To accentuate the geological context of the spectral measurements, the MASCS data have been overlain on the MDIS monochrome mosaic. Click on the image to explore the colorful diversity of surface materials in more detail! Instrument: Mercury Atmosphere and Surface Composition Spectrometer (MASCS) Map Projection: Orthographic VIRS Color Composite Wavelengths: 575 nm as red, 415 nm/750 nm as green, 310 nm/390 nm as blue Center Latitude (All Globes): 0° Center Longitude (Top Left Globe): 270° E Center Longitude (Top Right Globe): 0° E Center Longitude (Bottom Left Globe): 90° E Center Longitude (Bottom Right Globe): 180° E http://photojournal.jpl.nasa.gov/catalog/PIA19419

One of NASA Mariner 10 two TV cameras took this picture of a densely cratered region of Mercury on Sept. 21, 1974, 80 minutes prior to the spacecraft second close encounter with the planet.

During its flyby of Mercury, on January 14, 2008 NASA MESSENGER spacecraft acquired the first high-resolution spectra of the planet surface in ultraviolet, visible, and near-infrared light.

This is a montage of planetary images taken by spacecraft managed by NASA’s Jet Propulsion Laboratory in Pasadena, CA. Included are from top to bottom images of Mercury, Venus, Earth and Moon, Mars, Jupiter, Saturn, Uranus and Neptune.

This image, from NASA Mariner 10 spacecraft which launched in 1974, is of the Michelangelo Quadrangle, which lies in Mercury southern polar region. The Mercurian surface is heavily marred by numerous impact craters.

As comets C/2012 S1 ISON and the well-known short-period comet 2P/Encke both approached their closest distances to the Sun in November, 2013, they also passed close to the MESSENGER spacecraft orbiting the innermost planet Mercury.

The image shows part of a large, fresh crater with secondary crater chains located near Mercury equator on the side of the planet newly imaged on January 14, 2008 by NASA MESSENGER spacecraft.

Peaking into the Shadows. This image from NASA MESSENGER spacecraft features Laxness, a crater on Mercury northern plains named for Halldör Laxness, a twentieth-century Icelandic writer.

This visible-infrared image shows an incoming view of Mercury, about 80 minutes before NASA MESSENGER spacecraft closest pass of the planet on January 14, 2008, from a distance of about 27,000 kilometers 17,000 miles.

This image, from NASA Mariner 10 spacecraft which launched in 1974, shows intercrater plains and heavily cratered terrain typical of much of Mercury outside the area affected by the formation of the Caloris basin.

This computer photomosaic is of the Caloris Basin, the largest basin on Mercury. NASA Mariner 10 spacecraft imaged the region during its initial flyby of the planet after its launch in 1974.

This mosaic was assembled using NAC images acquired as the MESSENGER spacecraft approached the planet during the mission second Mercury flyby The Rembrandt impact basin is seen at the center of the mosaic.

On January 9, 2008, NASA MESSENGER spacecraft snapped one of its first images of Mercury at a distance of about 2.7 million kilometers 1.7 million miles from the planet.

Hemingway crater is seen in this color view of Mercury surface as seen by NASA MESSENGER spacecraft. Hemingway is the 130-km 81-mile diameter crater with a relatively brown floor and small patch of dark blue in its center.

This is a montage of planetary images taken by spacecraft managed by NASA’s Jet Propulsion Laboratory in Pasadena, CA. Included are from top to bottom images of Mercury, Venus, Earth and Moon, Mars, Jupiter, Saturn, Uranus and Neptune.

As NASA MESSENGER spacecraft team continued to study the high-resolution images taken during the Mercury flyby encounter on January 14, 2008, scarps cliffs that extend for long distances were discovered.

It difficult to get a sense of scale when viewing Saturn rings, but the Cassini Division seen here between the bright B ring and dimmer A ring is almost as wide as the planet Mercury as seen by NASA Cassini spacecraft.

This is an updated montage of planetary images taken by spacecraft managed by NASA’s Jet Propulsion Laboratory in Pasadena, CA. Included are from top to bottom images of Mercury, Venus, Earth and Moon, Mars, Jupiter, Saturn, Uranus and Neptune.

This image, from NASA Mariner 10 spacecraft which launched in 1974, is of the Borealis area H-1, located in Mercury northern hemisphere. The north pole is visible at the top of the image.

This false-color image of Mercury captured by NASA MESSENGER spacecraft shows the great Caloris impact basin, visible here as a large, circular, orange feature in the center of the picture.

The cliff-like feature crossing this image from NASA MESSENGER spacecraft from top to bottom is one of Mercury famed lobate scarps, and is called Pourquoi-Pas Rupes.

This image mosaic from NASA MESSENGER spacecraft shows an unnamed ridge in the northern volcanic plains of Mercury. Wrinkle ridges like this are interpreted to be tectonic in origin and are usually only found in volcanic plains. Six individual MDIS images are part of this mosaic. Instruments: Mercury Dual Imaging System (MDIS) Latitude: 79° Longitude: 118° E Scale: The ridge is approximately 140 kilometers (87 miles) long http://photojournal.jpl.nasa.gov/catalog/PIA19413

S61-03248 (21 July 1961) --- Mercury-Redstone 4 (MR-4) launch of Virgil I. Grissom on July 21, 1961, from Cape Canaveral, Florida. Photo credit: NASA

Astronaut L. Gordon Cooper, Jr., one of the original seven astronauts for Mercury Project selected by NASA on April 27, 1959. The MA-9 mission, boosted by the Mercury-Atlas launch vehicle, was the last flight of the Mercury Project. The Faith 7 spacecraft orbited the Earth 22 times in 1-1/2 days.

KENNEDY SPACE CENTER, FLA. -- CHAMBER TEST - Project Mercury astronaut Virgil I. 'Gus' Grissom, assisted by McDonnell technicians, leaves Mercury spacecraft, dubbed Liberty Bell 7, following simulated flight.

62-MA6-55 (1962) --- Astronaut John H. Glenn Jr., pilot of the Mercury Atlas 6 (MA-6) spaceflight, poses for a photo with the Mercury "Friendship 7" spacecraft during preflight activities. Photo credit: NASA

S62-00303 (20 Feb. 1962) --- A camera onboard the "Friendship 7" Mercury spacecraft photographs astronaut John H. Glenn Jr. during the Mercury-Atlas 6 spaceflight. Photo credit: NASA

S62-00302 (20 Feb. 1962) --- A camera onboard the "Friendship 7" Mercury spacecraft photographs astronaut John H. Glenn Jr. during his Mercury-Atlas 6 spaceflight. Photo credit: NASA

S61-03256 (13 Sept. 1961) --- Recovery of Mercury spacecraft at end of the Mercury-Atlas 4 (MA-4) mission. Notice the extended antenna on top of the capsule. Photo credit: NASA

KENNEDY SPACE CENTER, FLA. - Shipped in an air-conditioned transportation van from NASA’s Goddard Space Flight Center in Greenbelt, Md., NASA’s MESSENGER spacecraft, the first Mercury orbiter, arrives at the Astrotech Space Operations processing facilities near KSC. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be offloaded and taken into a high bay clean room. After the spacecraft is removed from its shipping container, employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.