Project Mercury

Project Mercury
Duration	1959-1963
Goal	Place Americans into orbit for as long as one day
Achievements	First manned flight: May 5, 1961 First orbital flight: February 20, 1962 One+ day flight: May 15-16, 1963
Crew	One man
Launch vehicles	Little Joe, Redstone, Atlas D
Organization	NASA
Related programs	Gemini and Apollo

Project Mercury was the first human spaceflight program of the United States. It ran from 1959 through 1963 with the goal of putting a human in orbit around the Earth. The Mercury-Atlas 6 flight on February 20, 1962, was the first American flight to achieve this goal.^[1]

The program included 20 unmanned launches, followed by two suborbital and four orbital flights with astronaut pilots. Early planning and research were carried out by the National Advisory Committee for Aeronautics (NACA),^[2] but the program was officially conducted by its successor organization, NASA. Mercury laid the groundwork for Project Gemini and the follow-on Apollo moon-landing program.

The project name came from Mercury, a Roman mythological god often seen as a symbol of speed. Mercury is also the name of the innermost planet of the Solar System, which moves faster than any other and hence provides an image of speed, although Project Mercury had no real connection to the planet.

Goals and guidelines

John Glenn during the first American orbital flight in 1962

The goals of the program were to orbit a manned spacecraft around Earth, investigate the pilot's ability to function in space and to recover both pilot and spacecraft safely.^[3]

NASA also established program guidelines: existing technology and off-the-shelf equipment should be used wherever practical, the simplest and most reliable approach to system design would be followed, an existing launch vehicle would be employed to place the spacecraft into orbit, and a progressive and logical test program would be used.

Project requirements for the spacecraft were that it must be fitted with a reliable launch escape system to separate the spacecraft and its astronaut from its launch vehicle in case of impending failure; the pilot must have been given the capability of manually controlling the attitude of the spacecraft; the spacecraft must carry a retro-rocket system capable of reliably providing the necessary impulse to bring the spacecraft out of orbit; a zero-lift body utilizing drag braking to be used for reentry; and that the spacecraft design must satisfy the requirements for a landing on water.^[4]

Contractors

On October 7, 1958, T. Keith Glennan, the first administrator of NASA, approved the Mercury project.^[5][6] On December 17 Glennan announced Project Mercury publicly.^[7]

On December 29, 1958 North American Aviation was awarded a contract to design and build Little Joe launch vehicles to be used for altitude flight testing of the Mercury launch escape system.^[8] In January 1959 McDonnell Aircraft Corporation was chosen to be prime contractor for the Mercury spacecraft, and the contract for 12 spacecraft was awarded in February. In April seven astronauts, known as the Mercury Seven or more formally as Astronaut Group 1, were selected to participate in the Mercury program.

In May 1959 North American Aviation delivered the first two Little Joes, and in June, an Atlas D launch vehicle named Big Joe was delivered, for use in a suborbital heat shield test flight. In July, the planned use of the Jupiter rocket as a suborbital launch vehicle was changed to the Redstone.^[9] In October General Electric delivered to McDonnell the ablative heat shield designated for installation on the first Mercury spacecraft. In December the launch vehicle for Mercury-Redstone 1 was ready to begin static tests installed on a test stand at ABMA.

Design of spacecraft

Aerodynamic test on spacecraft model showing a protective layer formed in front of the heat shield

Spacecraft: 1. retrorockets, 2. heatshield, 3. crew compartment, 4. recovery compart., 5. antenna section, 6. escape tower

In January 1960 NASA awarded Western Electric Company a contract for the Mercury tracking network. The value of the contract was over $33 million.^[10] Also in January, McDonnell delivered the first production-type Mercury spacecraft, less than a year after award of the formal contract. On February 12, Christopher C. Kraft, Jr. was appointed to head the Mercury operations coordination group.^[11] In April, the first spacecraft was delivered to Wallops Island for the beach-abort test. The test was completed successfully on May 9.^[12]

Spacecraft

Interior and control

Because of their small size, it was said that the Mercury spacecraft were worn, not ridden. With 1.7 m³ of habitable volume, the spacecraft was just large enough for the single crew member. Inside were 120 controls: 55 electrical switches, 30 fuses and 35 mechanical levers.^[13] The spacecraft was designed by Max Faget and NASA's Space Task Group.^{[14][15]:26–28}

Despite the astronauts' test pilot experience NASA at first envisioned them as "minor participants" during their flights, causing many conflicts between the astronauts and engineers during the spacecraft's design. Nonetheless, contrary to other reports, the project's leaders always intended for pilots to be able to control their spacecraft, as they valued humans' ability to contribute to missions' success.^[15]:23–25 John Glenn's manual attitude adjustments during the first orbital flight were an example of the value of such control.^[15]:33 The astronauts requested—and received—a larger window and manual reentry controls.^[15]:24–25

Spacecraft and orbital mission

Spacecraft with astronaut. In orbit the astronaut was moving backwards. One orbit took 1½ hour^[16]

An orbital mission. Altitude 156 miles/250 km.^[17]

Mission profile

During the launch phase of the mission, the Mercury spacecraft and astronaut were protected from launch vehicle failures by the Launch Escape System. The LES consisted of a solid fuel, 52,000 lbf (231 kN) thrust rocket with three engine bells mounted on a tower above the spacecraft.^[15]:28 In the event of a launch abort, the LES would fire for one second, pulling the spacecraft and astronaut away from the launch vehicle and a possible explosion. The spacecraft would then descend on its parachute recovery system. After booster engine cutoff (BECO), the LES was no longer needed and was separated from the spacecraft by a solid fuel, 800 lbf (3.6 kN) thrust jettison rocket that fired for 1.5 seconds.

After a successful liftoff, the spacecraft fired three small clustered solid-fuel, 400 lbf (1.8 kN) thrust rockets for 1 second to separate the spacecraft from the launch vehicle. These rockets were called the posigrade rockets^[15]:28 (point D on illustration).

The spacecraft were only equipped with attitude control thrusters; after orbit insertion but before retrofire they could not change their orbit. There were three sets of high and low powered automatic control jets and separate manual jets, one for each axis (roll, pitch, and yaw), and supplied from two separate fuel tanks, one automatic and one manual. The pilot could use any one of the three thruster systems and fuel them from either of the two fuel tanks to provide spacecraft attitude control. The Mercury spacecraft was designed to be completely controllable from the ground in the event that something impaired the pilot's ability to function.

Heat shield and retropack. Small red posigrade rockets can be seen between retrograde rockets

The spacecraft had three solid-fuel, 1000 lbf (4.5 kN) thrust retrorockets that fired for 10 seconds each^[15]:28 (point F on illustration). One was sufficient to return the spacecraft to Earth if the other two failed. The firing sequence (known as ripple firing) required firing the first retro, followed by the second retro five seconds later (while the first was still firing). Five seconds after that, the third retro fired (while the second retro was still firing).

There was a small hinged metal flap at the nose of the spacecraft called the spoiler.^[pic.] If the spacecraft started to reenter nose first (another stable reentry attitude for the spacecraft), airflow over the spoiler would flip the spacecraft around to the proper, heatshield-first reentry attitude, a technique called shuttlecocking. During reentry, the astronaut would experience about 8 g-forces on an orbital mission, and 11–12 gs on a suborbital mission.

Initial designs for the spacecraft suggested the use of either beryllium heat-sink heat shields or an ablative shield. Extensive testing settled the issue – ablative shields proved to be reliable (so much so that the initial shield thickness was safely reduced, allowing a lower total spacecraft weight), and were easier to produce — at that time, beryllium was only produced in sufficient quantities by a single company in the U.S. — and cheaper. The surface of the heat shield had a coating of aluminum with glassfiber in many layers. As the temperature rose to 2,000 °F (1,100 °C) the layers would evaporate and take the heat with it. The spacecraft would become hot but not harmfully so.^[18]

Freedom 7 recovered by helicopter. Notice landing bag beneath spacecraft

After re-entry, a small, drogue parachute was deployed at 21,000 ft (6.4km) for first lowering of speed. The main parachute was deployed at 10,000 ft (3 km), further slowing the spacecraft in preparation for landing. Just before hitting the water, a landing bag inflated from behind the heat shield to reduce the force of impact. Upon landing, additional bags inflated around the nose of the craft to keep the capsule upright in the water, and the parachutes were released. Once the recovery helicopter hooked onto the spacecraft, the astronaut blew the escape hatch to exit the capsule. It was also possible to exit the capsule through the nose cone.^[18]

Production summary

NASA ordered 20 production spacecraft, numbered 1 through 20, from McDonnell Aircraft Company, St. Louis, Missouri. Five of the 20, Nos. 10, 12, 15, 17, and 19, were not flown.^[19] Spacecraft No. 3 and No. 4 were destroyed during unmanned test flights.^[19] Spacecraft No. 11 sank^[19] and was recovered from the bottom of the Atlantic Ocean after 38 years.^[20] Some spacecraft were modified after initial production (refurbished after launch abort, modified for longer missions, etc.) and received a letter designation after their number, examples 2B, 15B. Some spacecraft were modified twice; for example, spacecraft 15 became 15A and then 15B.^[21]

A number of Mercury boilerplate spacecraft (including mockup/prototype/replica spacecraft, made from non-flight materials or lacking production spacecraft systems and/or hardware) were also made by NASA and McDonnell Aircraft.^[22][23] They were designed and used to test spacecraft recovery systems, and escape tower and rocket motors. Formal tests were done on test pad at Langley and at Wallops Island using the Little Joe and Big Joe rockets.^[24]

Launch vehicles

Mercury rockets

Little Joe, used for test of escape system

Redstone, used for suborbital missions

Atlas, used for orbital missions

The Mercury program used three launch vehicles:^[15]:28–30

• Little Joe (height: 55 ft) – for launch escape system tests at altitude. Eight robotic flights were made, two of which carried live monkeys. It was a solid-fuel rocket designed specially for the Mercury program. Together with a Mercury boilerplate it was used to test the escape tower and abort procedures.^[25]
• Redstone (height 83 ft) – 1-stage rocket for suborbital (ballistic) flights. Four robotic flights were made, one of which carried a chimpanzee. After that it was used for the first two manned flights. The Jupiter rocket was originally considered for the suborbital launch vehicle, but were replaced with the Redstone in July 1959 due to budget constraints.

• Atlas D (height 94 ft) – 2-stage rocket for orbital manned flight. Six robotic test flights were made, four suborbital and two orbital one of which carried a chimpanzee. After that it was used for four manned orbital flights. The Atlas D rocket required extra strengthening^[26] in order to handle the increased weight of the Mercury spacecraft beyond that of the nuclear warheads they were designed to carry.

The Titan missile was also considered for use for later Mercury missions;^[27] however, the Mercury program was terminated before these missions were flown. Instead, the Titan was used for the Gemini program which followed Mercury. The Mercury program also used a Scout rocket for a single flight, Mercury-Scout 1, which was intended to launch a small satellite designed to evaluate the worldwide Mercury Tracking Network. Launched on November 1, 1961, however, the rocket was destroyed by the Range Safety Officer after 44 seconds of flight.^[28]

Unmanned flights

The program included 20 robotic launches. Not all of these were intended to reach space and not all were successful in completing their objectives. Four of these flights included non-human primates, starting with the fifth flight (1959) which launched a Rhesus macaque named Sam^[29] (after the Air Force's School of Aerospace Medicine). The Mercury program's complete roster of non-human space-farers is given below:

• Sam, a Rhesus macaque, launched 4 December 1959 on Little Joe 2 to 85 km altitude.
• Miss Sam, a Rhesus macaque, launched 21 January 1960 on Little Joe 1B to 15 km altitude.
• Ham, a chimpanzee, launched 31 January 1961 on Mercury-Redstone 2 for a suborbital flight.
• Enos, a chimpanzee, launched 29 November 1961 on Mercury-Atlas 5 for a 2-orbit flight.

All missions were named after the rocket used and the number of missions reached by that rocket. The Redstone and Atlas rockets were meant for manned flights but they had to be tested in unmanned flights first. Therefore the first manned mission with the Redstone rocket was Mercury-Redstone 3 and the first with Atlas, the Mercury-Atlas 6.

List of unmanned flights

Mission	Rocket	Call Sign	Launch Date	Launch Time	Duration	Remarks
Mercury-Jupiter	Jupiter	N/A	N/A	N/A	N/A	Canceled in July, 1959 – Proposed suborbital launch vehicle for Mercury. Not flown.
Little Joe 1	Little Joe	LJ-1	21 August 1959	N/A	00d 00h 00 m 20s	Test of launch escape system during flight.
Big Joe 1	Atlas 10-D	Big Joe 1	9 September 1959	N/A	00d 00h 13 m	Test of heat shield and Atlas / spacecraft interface
Little Joe 6	Little Joe	LJ-6	4 October 1959	N/A	00d 00h 05 m 10s	Test of spacecraft aerodynamics and integrity
Little Joe 1A	Little Joe	LJ-1A	4 November 1959	N/A	00d 00h 08 m 11s	Test of launch escape system during flight
Little Joe 2	Little Joe	LJ-2	4 December 1959	N/A	00d 00h 11 m 06s	Carried Sam the monkey to 85 kilometres in altitude
Little Joe 1B	Little Joe	LJ-1B	21 January 1960	N/A	00d 00h 08 m 35s	Carried Miss Sam the monkey to 9.3 statute miles (15 kilometres) in altitude
Beach Abort	Launch escape system	Beach Abort	9 May 1960	N/A	00d 00h 01 m 31s	Test of the off-the-pad abort system
Mercury-Atlas 1	Atlas	MA-1	29 July 1960	13:13 UTC	00d 00h 03 m 18s	First flight of Mercury / Atlas
Little Joe 5	Little Joe	LJ-5	8 November 1960	N/A	00d 00h 02 m 22s	First flight of a production Mercury spacecraft
Mercury-Redstone 1	Redstone	MR-1	21 November 1960	N/A	00d 00h 00 m 02s	Launched 4 inches (100 mm); settled back on pad due to electrical malfunction
Mercury-Redstone 1A	Redstone	MR-1A	19 December 1960	N/A	00d 00h 15 m 45s	First flight of Mercury / Redstone
Mercury-Redstone 2	Redstone	MR-2	31 January 1961	16:55 UTC	00d 00h 16 m 39s	Carried Ham the chimpanzee on suborbital flight
Mercury-Atlas 2	Atlas	MA-2	21 February 1961	14:10 UTC	00d 00h 17 m 56s	Unmanned test
Little Joe 5A	Little Joe	LJ-5A	18 March 1961	N/A	00d 00h 23 m 48s	Test of the launch escape system during the most severe conditions of a launch
Mercury-Redstone BD	Redstone	MR-BD	24 March 1961	17:30 UTC	00d 00h 8 m 23s	Redstone development test flight
Mercury-Atlas 3	Atlas	MA-3	25 April 1961	16:15 UTC	00d 00h 07 m 19s	Contained "robot astronaut"
Little Joe 5B	Little Joe	AB-1	28 April 1961	N/A	00d 00h 05 m 25s	Test of the launch escape system during the most severe conditions of a launch
Mercury-Atlas 4	Atlas	MA-4	13 September 1961	14:09 UTC	00d 01h 49 m 20s	Unmanned test, completed one orbit
Mercury-Scout 1	Scout	MS-1	1 November 1961	15:32 UTC	00d 00h 00 m 44s	Test of Mercury tracking network
Mercury-Atlas 5	Atlas	MA-5	29 November 1961	15:08 UTC	00d 03h 20 m 59s	Carried Enos the chimpanzee on a two-orbit flight

Manned flights

Astronauts

L to R: Grissom, Shepard, Carpenter, Schirra, Slayton, Glenn, Cooper, 1962

Manned Mercury mission launches

The first Americans to venture into space were drawn from a group of 110 military pilots^[30] chosen for their flight test experience and because they met certain physical requirements. NASA announced the selection of seven of these – known as the Mercury Seven – as astronauts on 9 April 1959,^[31] though only six of the seven flew Mercury missions, after Slayton was grounded due to a heart condition. In order of flight:

• Alan Bartlett Shepard, Jr., USN (1923–1998); first American in space, May 1961
• Virgil Ivan "Gus" Grissom, USAF (1926–1967); flew 21 July 1961. Died during Apollo 1 pre-launch test
• John Herschel Glenn, Jr., USMC (born 1921); first American to orbit the Earth, 20 February 1962
• Malcolm Scott Carpenter, USN (born 1925), flew 24 May 1962
• Walter Marty "Wally" Schirra, Jr., USN (1923–2007), flew 3 October 1962
• Leroy Gordon "Gordo" Cooper, Jr., USAF (1927–2004), flew 15 May 1963
• Donald Kent "Deke" Slayton, USAF (1924–1993); grounded in 1962, but reinstated in 1972 and flew on the Apollo-Soyuz Test Project in 1975.^[32]

Just like the rockets and spacecraft were tested in details by unmanned flights, the astronauts went through a training program in special facilities and model arrangements. Some tests were made to see their response to weightlessness on one hand and high g forces on the other. Other parts of the training was meant to give them practice in maneuvering the spacecraft and get in and out of its narrow openings wearing a space suit. (See also: Training in Mercury Program gallery).

Flight of the first manned mission, 1961

Piloted Mercury launches

In all, 6 manned missions were made. The most famous flights were the first and the third. In the first on May 5, 1961,^[33] Alan Shepard became the first American in space and the second person ever after Yuri Gagarin of the Soviet Union who flew one month before.^[34] Gagarin also orbited the earth, which John Glenn did as the second ^[35] person after him, in February 1962, at the third Mercury flight.^[36] Three more orbital flights were made, the last in 1963.^[33]

2 suborbital flights were cancelled; they began to look embarrassing after Soviet had made a day long orbital flight in August 1961. Three orbital flights were also cancelled since it was clear that the spacecraft had reached its limits. At the last flight the batteries were exhausted before reentry but, luckily, the spacecraft landed safely.^[37]

Tracking control of manned mission (Mercury-Atlas 8)

Control Center, Florida

The 6 orbits and the tracking stations

Beginning with Alan Shepard's Freedom 7 flight, the astronauts named their own spacecraft, and all added "7" to the name to acknowledge the teamwork of their fellow astronauts.

List of flights

Mission	Callsign	Rocket	Designation	Pilot	Launch Date	Launch Time	Duration	Remarks
Mercury-Redstone 3	Freedom 7	Redstone	MR-3	Shepard	5 May 1961	14:34 UTC	00d 00h 15 m 28s	First American to make a suborbital flight into space
Mercury-Redstone 4	Liberty Bell 7	Redstone	MR-4	Grissom	21 July 1961	12:20 UTC	00d 00h 15 m 37s	Second suborbital flight. Spacecraft sank before recovery when hatch unexpectedly blew off, recovered 1999.
Mercury-Atlas 6	Friendship 7	Atlas	MA-6	Glenn	20 February 1962	14:47 UTC	00d 04h 55 m 23s	First American to orbit the Earth (for a total of 3 orbits). Spacecraft's retropack retained during re-entry due to concerns about heat shield.
Mercury-Atlas 7	Aurora 7	Atlas	MA-7	Carpenter	24 May 1962	12:45 UTC	00d 04h 56 m 15s	3 orbits. Reentered off-target by 402 km. Pilot Carpenter replaced Deke Slayton.
Mercury-Atlas 8	Sigma 7	Atlas	MA-8	Schirra	3 October 1962	12:15 UTC	00d 09h 13 m 11s	Carried out engineering tests; six orbits
Mercury-Atlas 9	Faith 7	Atlas	MA-9	Cooper	15 May 1963	13:04 UTC	01d 10h 19 m 49s	First American in space for over a day. Last American to orbit the Earth solo. 22 orbits.

List of cancelled flights

Mission	Callsign	Rocket	Designation	Pilot	Launch Date	Launch Time	Duration	Remarks
Mercury-Atlas 10	Freedom 7-II	Atlas	MA-10	Shepard	N/A	N/A	N/A	Intended to be a three-day mission in October 1963; canceled 13 June 1963.
Mercury-Atlas 11		Atlas	MA-11	Grissom	N/A	N/A	N/A	Intended to be a one-day mission in 1963; canceled by October 1962.
Mercury-Atlas 12		Atlas	MA-12	Schirra	N/A	N/A	N/A	Intended to be a one-day mission in 1963. Canceled by October 1962.

Tracking network

To track the manned orbit missions a network of radio stations was built around the equator. Two other tracking networks already existed: one for unmanned missions and one for deep space missions, however they were not adequate for manned missions.

Deep space missions require a few big telescopes whereas earth orbit manned missions require many small radiostations at points that the spacecraft will pass over on its way. Unmanned missions need the same kind of radio stations but in smaller number. These differences led NASA to build an independent network for the manned missions.^{[citation needed]}

Program cost

In January 1969, NASA prepared for the US Congress an estimate of the costs for projects Mercury, Gemini, and Apollo (to the first manned Moon landing). This estimate gave the cost of Project Mercury as $392.6 million, broken down as follows:^[38]

• Spacecraft: $135.3 million
• Launch vehicles: $82.9 million
• Operations: $49.3 million
• Tracking operations and equipment: $71.9 million
• Facilities: $53.2 million

Legacy

Insignias

Mercury program monument at LC-14

Flight patches that purport to be patches from various Mercury missions are available to the public. In reality, these patches were designed by private entrepreneurs several years after the Mercury program. When mission patches were created by crews in the Gemini program, this caused a public demand for Mercury flight patches, which was filled by these entrepreneurs. The only patches the Mercury astronauts wore, however, were the NASA logo and a name tag. Each manned Mercury spacecraft was decorated with a flight insignia featuring the spacecraft name (Freedom 7, etc.).

Films

An American film about the Mercury project is The Right Stuff from 1983 adapted from Tom Wolfe's 1979 book by the same name. It also deals with the test pilots who were involved in high-speed aeronautical research that preceded the project.^[39]

Stamps

Project Mercury issue of 1962

In 1962, the US Post Office honored the Mercury-Atlas 6 flight with the Project Mercury commemorative stamp, the first U.S. postal issue to depict a manned spacecraft. The stamp first went on sale in Cape Canaveral, Florida on February 20, 1962, the same day as the Project Mercury launch putting the first U.S. astronaut into orbit. On May 4th, 2011, the US Postal Service released a stamp commemorating the 50th anniversary of the May 5th, 1961 flight of Freedom 7 (which carried Alan Shepard into space).^[40]

Awards

On February 25, 2011, the Institute of Electrical and Electronic Engineers, the world's largest technical professional society, awarded Boeing Company (successor to McDonnell Douglas) a Milestone Award for important inventions which debuted on the Mercury spacecraft. The IEEE bestows this honor on projects that were accomplished at least 25 years in the past. Boeing received the award in recognition of Project Mercury's pioneering "navigation and control instruments, autopilot, rate stabilization and control, and fly-by-wire systems."^[41]

See also

Spaceflight portal

• Man In Space Soonest
• Mercury 13
• Mercury-Redstone 1A
• Mercury-Atlas 1
• Mercury-Atlas 2
• Mercury-Atlas 3
• Mercury-Atlas 4
• Mercury-Atlas 10
• Navy Mark IV – spacesuit
• Splashdown

References

1. ^ "Mercury-Atlas 6 (23)". NASA. http://www.nasa.gov/mission_pages/mercury/missions/friendship7.html. 
2. ^ "Major Events Leading to Project Mercury". NASA. http://history.nasa.gov/SP-4001/p1a.htm. 
3. ^ "Project Mercury". NASA Public Affairs Office. http://www-pao.ksc.nasa.gov/history/mercury/mercury-goals.htm. 
4. ^ "Mercury Goals and Guidelines". NASA Public Affairs Office. http://www-pao.ksc.nasa.gov/history/mercury/mercury-overview.htm. 
5. ^ Prepared by James M. Grimwood. "Research and Development Phase of Project Mercury". NASA MSC. http://history.nasa.gov/SP-4001/p2a.htm. 
6. ^ Cheryl L. Mansfield. "In Their Footsteps: The Mercury 7". NASA. http://www.nasa.gov/centers/kennedy/about/history/mercury7.html. 
7. ^ "Project Mercury". U.S. Centennial of Flight Commission. http://www.centennialofflight.gov/essay/SPACEFLIGHT/Mercury/SP17.htm. 
8. ^ "Little Joe Launch Vehicle". Boeing. http://www.boeing.com/history/bna/little_joe.html. 
9. ^ "Mercury-Jupiter 2 (MJ-2)". Encyclopedia Astronautica. http://www.astronautix.com/flights/merr2mj2.htm. 
10. ^ "Chronology – Quarter 1 1960". Encyclopedia Astronautica. http://www.astronautix.com/chrono/1960.htm. 
11. ^ "Christopher C Kraft, Jr American Manager. Born 1924.". Encyclopedia Astronautica. http://www.astronautix.com/astros/kraft.htm. 
12. ^ "PART II (B), Research and Development Phase of Project Mercury, January 1960 through May 5, 1961". NASA. http://history.nasa.gov/SP-4001/p2b.htm. 
13. ^ "Project Mercury". U.S Centennial of flight commission. http://www.centennialofflight.gov/essay/SPACEFLIGHT/Mercury/SP17.htm. 
14. ^ "Biographical Data, Dr. Maxime A. Faget". NASA. http://history.nasa.gov/Apollo204/faget.html. 
15. ^ ^{a b c d e f g h} Logsdon, John M. with Roger D. Launius (editors) Exploring the Unknown: Selected Documents in the History of the U.S. Civil Space Program / Volume VII Human Spaceflight: Projects Mercury, Gemini, and Apollo The NASA History Series, 2008.
16. ^ "Space log Mercury 6". NASA. http://mercury6.spacelog.org/original/162/. Retrieved 2011-10-05. 
17. ^ "Atlas Mercury manual, page 4". NASA. http://www.scribd.com/doc/49295067/Mercury-Atlas-Mission-3. Retrieved 2011-10-02. 
18. ^ ^{a b} "How Project Mercury Worked". How Stuff Works. http://science.howstuffworks.com/project-mercury2.htm. Retrieved 2011-10-04. 
19. ^ ^{a b c} "Appendix 6 – Location of Mercury Spacecraft, and Exhibit Schedule". NASA. http://history.nasa.gov/SP-4001/app6.htm. 
20. ^ "Liberty Bell 7 capsule raised from ocean floor". CNN. http://www.cnn.com/TECH/space/9907/20/grissom.capsule.01/. 
21. ^ "Mercury MA-10". Encyclopedia Astronautica. http://www.astronautix.com/flights/meryma10.htm. 
22. ^ "Boilerplate Mercury Capsule". NASA. http://grin.hq.nasa.gov/ABSTRACTS/GPN-2000-003008.html. 
23. ^ "Mercury". Encyclopedia Astronautica. http://www.astronautix.com/project/mercury.htm. 
24. ^ NASA Mercury History Sections #44 and #47
25. ^ "Mercury Boilerplate Tests". Astronautix.com. http://www.astronautix.com/project/mercury.htm. Retrieved 2010-12-10. 
26. ^ "MA-2: Trussed Atlas Qualifies the Capsule". NASA. http://history.nasa.gov/SP-4201/ch10-4.htm. 
27. ^ "More Than a Spacecraft". NASA. http://history.nasa.gov/SP-4203/ch3-2.htm. 
28. ^ "Mercury Scout 1". NASA. http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=MERCS1. 
29. ^ "Sam the Monkey After His Ride in the Little Joe 2 Spacecraft". NASA. http://grin.hq.nasa.gov/ABSTRACTS/GPN-2002-000042.html. 
30. ^ "Alan B. Shepard, Jr.". NASA. http://history.nasa.gov/40thmerc7/shepard.htm. 
31. ^ "The 40th Anniversary of the Mercury Seven". NASA. http://history.nasa.gov/40thmerc7/intro.htm. 
32. ^ "APOLLO-SOYUZ". NASA. http://history.nasa.gov/apollo/apsoyhist.html. 
33. ^ ^{a b} "Mercury Manned Flights Summary". NASA. http://www.nasa.gov/mission_pages/mercury/missions/manned_flights.html. Retrieved 2011-10-09. 
34. ^ "NASA history, Gagarin". NASA. http://www.nasa.gov/topics/history/features/gagarin/gagarin.html. Retrieved 2011-10-09. 
35. ^ Astronautix, Vostok 2: the cosmonaut Titov came between them
36. ^ "NASA, John Glenn". NASA. http://www.nasa.gov/centers/glenn/about/bios/mercury_mission.html. Retrieved 2011-10-09. 
37. ^ "Mercury". Encyclopedia Astronautica. http://www.astronautix.com/project/mercury.htm. Retrieved 2011-10-09. 
38. ^ Wilford, John Noble (July 1969). We Reach the Moon. New York: Bantam Books. p. 67. 
39. ^ "The Right Stuff". IMdB. http://www.imdb.com/title/tt0086197/. Retrieved 2011-10-04. 
40. ^ "Astronaut Alan Shepard Immortalized on Forever Stamp". US Postal Service. http://www.usps.com/communications/newsroom/2011/pr11_044.htm. Retrieved May 5th, 2011. 
41. ^ Boeing Press Release, February 25, 2011

Further reading

• Chris Kraft, Flight: My Life in Mission Control (March 2001). Factual, written by one of the pivotal figures in America's space programme, whose involvement ran from the early days of NACA through the formation of NASA, Mercury, Gemini, Apollo, ASTP, Skylab and the early days of Shuttle operations. Hardcover, 371 pages, ISBN 0-525-94571-7 or paperback (2002) ISBN 0-452-28304-3.
• Gene Kranz, Failure is Not an Option. Factual, from the standpoint of a chief flight controller during the Mercury, Gemini, and Apollo space programs. ISBN 0-7432-0079-9
• Tom Wolfe, The Right Stuff. (Wolfe interviewed many of those involved).
• Schirra, Grissom, Glenn, Slayton, Shepherd, Carpenter, Cooper, We Seven. (ISBN B00005X54G); Simon & Schuster – 1962. Factual; a collection of articles written by the seven Mercury astronauts describing events from their points of view.
• Francis French and Colin Burgess, Into That Silent Sea:Trailblazers of the Space Era 1961–1965. ISBN 978-0-8032-1146-9. History of the Mercury program with many unique first-hand interviews with the participants.
• James M. Grimwood, This New Ocean: A History of Project Mercury
• James M. Grimwood, Project Mercury – A Chronology
• Mae Mills Link, Space Medicine In Project Mercury
• Results of the first US manned orbital space flight – Feb 20, 1962 (Friendship 7) NASA report – (PDF format)
• Results of the second u.s. manned orbital space flight, May 24, 1962 (Aurora 7) NASA report – (PDF format)
• This New Ocean: A History of Project Mercury – NASA report (PDF format)
• Chronology of Project Mercury – NASA report (PDF format)

External links

• The Mercury Project (Kennedy Space Center)
• Project Mercury A Chronology (Prepared by James M. Grimwood)
• Space Medicine In Project Mercury By Mae Mills Link
• Project Mercury Drawings and Technical Diagrams
• Project Mercury Simulator for Mac and PC
• The Mercury Redstone Project (PDF) December 1964
• Project Mercury familiarization manual (PDF) November 1961
• Various PDFs of historical Mercury documents including familiarization manuals.
• NASA History Series Publications (many of which are on-line)
• U.S. Spaceflight History- Mercury Program