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Project Gemini

By Wikipedia,
the free encyclopedia,

http://en.wikipedia.org/wiki/Gemini_program

Project Gemini was the second human spaceflight program of the National Aeronautics and Space Administration. It operated between Projects Mercury and Apollo, with 10 manned flights occurring in 1965 and 1966. Its objective was to develop techniques for advanced space travel, notably those necessary for Project Apollo, whose objective was to land humans on the Moon. Gemini missions included the first American extravehicular activity, and new orbital maneuvers including rendezvous and docking.

Program objectives

The Gemini Program was conceived after it became evident to NASA officials that an intermediate step was required between the projects Mercury and Apollo. The major objectives assigned to Gemini were:

  • To subject two crewmembers and supporting equipment to long-duration flights, a requirement for projected later trips to the Moon or deeper space.
  • To effect rendezvous and docking with other orbiting vehicles, and to maneuver the docked vehicles in space, using the propulsion system of the target vehicle for such maneuvers.
  • To perfect methods of reentry and landing the spacecraft at a pre-selected land-landing point.
  • To gain additional information concerning the effects of weightlessness on crew members and to record the physiological reactions of crew members during long-duration flights.
  • To accomplish EVA, (Extra Vehicular Activity) or space-walks outside the protection of the space craft.

After 10 successful flights, the Gemini program clearly placed the United States in the lead over the Soviet Union in manned spaceflight. The flight of Gemini VIII concluded with the successful emergency recovery of the tumbling orbiting spacecraft piloted by Neil Armstrong and David Scott.

Specifications

Gemini was originally seen as a simple extrapolation of the Mercury program, and thus early on was called Mercury Mark II. The actual program had little in common with Mercury and was superior to even Apollo in some ways. This was mainly a result of its late start date, which allowed it to benefit from much that had been learned during the early stages of the Apollo project (which, despite its later launch dates, was actually begun before Gemini).

Its primary difference from Mercury was that the earlier spacecraft had all systems other than the reentry rockets situated within the capsule, to which access of nearly all was through the astronaut's hatchway, while Gemini had many power, propulsion, and life support systems in a detachable module like a huge bowl; many components in the capsule itself were reachable each through its own small access door. The original intention was for Gemini to land on solid ground instead of at sea, using a paraglider rather than a parachute, and for the crew to be seated upright controlling the forward motion of the craft before its landing. To facilitate this, the parachute cord did not attach just to the nose of the craft; there was an additional attachment point for balance near the heat shield. This cord was covered by a strip of metal between the doors. Early short-duration missions had their electrical power supplied by batteries; later endurance missions had the first fuel cells in manned spacecraft.

The "Gemini" designation comes from the fact that each spacecraft held two people, as "gemini" in Latin means "twins". Gemini is also the name of the third constellation of the Zodiac and its twin stars, Castor and Pollux.

Unlike Mercury, which could only change its orientation in space, the Gemini spacecraft could alter its orbit. It could also dock with the Agena Target Vehicle, which had its own large rocket engine and was used to perform large orbital changes. Gemini was the first American manned spacecraft to include an onboard computer, the Gemini Guidance Computer, to facilitate management and control of mission maneuvers. It was also unlike other NASA craft in that it used ejection seats, in-flight radar and an artificial horizon - devices borrowed from the aviation industry. Using ejection seats to push astronauts to safety was first employed by the Soviet Union in the Vostok craft manned by cosmonaut Yuri Gagarin.

The Gemini program cost $5.4 billion.

Team

Gemini was designed by a Canadian, Jim Chamberlin, formerly the chief aerodynamicist on the Avro Arrow fighter interceptor program with Avro Canada. Chamberlin joined NASA along with 25 senior Avro engineers after cancellation of the Arrow program, and became head of the U.S. Space Task Group’s engineering division in charge of Gemini. The main contractor was McDonnell, which had lost out on main contracts for the Apollo Project. McDonnell sought to extend the program by proposing a Gemini craft which could be used to fly a cislunar mission and even achieve a manned lunar landing earlier and at less cost than Apollo, but these proposals were rejected.

In addition, astronaut Gus Grissom was heavily involved in the development and design of the Gemini Spacecraft. He writes in his posthumous 1968 book Gemini! that the realization of Project Mercury's end and the unlikelihood of his having another flight in that program prompted him to focus all of his efforts on the upcoming Gemini Program.

The Gemini program was managed by the Manned Spacecraft Center, Houston, Texas, under direction of the Office of Manned Space Flight, NASA Headquarters, Washington, D.C, Dr. George E. Mueller, Associate Administrator of NASA for Manned Space Flight, served as acting director of the Gemini program. William C. Schneider, Deputy Director of Manned Space Flight for Mission Operations, served as Mission Director on all Gemini flights beginning with Gemini VI.

Gemini applications

Military


Replica of a Gemini spacecraft at the Neil Armstrong Air and Space Museum
Replica of a Gemini spacecraft at the Neil Armstrong Air and Space Museum

A cutaway of the Project Gemini spacecraft
A cutaway of the Project Gemini spacecraft

The United States Air Force had an interest in the system, and decided to use its own modification of the spacecraft as the crew vehicle for the Manned Orbital Laboratory. To this end, one of the unmanned Gemini spacecraft was refurbished and flown again atop a mockup of the MOL, sent into space by a Titan III-M. This was the first time a spacecraft went into space twice.

The USAF also had the notion of adapting the Gemini spacecraft for military applications, such as crude observation of the ground (no specialized reconnaissance camera could be carried) and practicing making rendezvous with suspicious satellites. This project was called Blue Gemini. The US Air Force did not like the fact that Gemini would have to be recovered by the US Navy, so they intended for Blue Gemini eventually to use the paraglider and land on three skids, something from the original design of Gemini.

At first some within NASA welcomed sharing of the cost with the USAF, but it was later agreed that NASA was better off operating Project Gemini by itself. MOL was cancelled in 1968 and Blue Gemini too was cancelled without any use by military astronauts.

Other proposals

Other Gemini derivatives were proposed, including Big Gemini, Gemini LOR, Gemini Lunar Lander, Gemini-Centaur, Gemini Ferry, Gemini Transport, Gemini - Saturn I, Gemini - Saturn IB, Gemini - Saturn V, Gemini Pecan, Extended Mission Gemini, Gemini - Double Transtage, Gemini Satellite Inspector, Gemini Lunar Surface Rescue Spacecraft, Gemini Observatory, Gemini Para glider, Rescue Gemini, Winged Gemini, Gemini LORV and Gemini Lunar Surface Survival Shelter.

Current

In 2005, NASA Administrator Michael Griffin announced that the new Orion spacecraft, an Apollo-derived spacecraft, would use the Gemini/Agena chasedown and docking technique when NASA starts sending crews back out to the Moon by 2020. The Orion, which will replace the Space Shuttle (which currently lands on a conventional runway similar to the early Gemini and Blue Gemini paraglider/skids technique), was originally designed to land on solid ground using deployable airbags or a Soyuz-style retrorocket system, but it is currently envisioned to be recovered in the ocean.

In addition, NASA may opt to replace the proposed launch escape system with the so-called Max Launch Abort System (MLAS) which would work in the same fashion as the Mercury and Apollo escape towers, but incorporate the rockets into the launch shroud itself, eliminating the tower altogether and allowing the Orion spacecraft to resemble the towerless Gemini-Titan launch system.


Liftoff of Gemini 6A from Pad 19 with astronauts Walter Schirra and Thomas Stafford aboard (15Dec65)
Liftoff of Gemini 6A from Pad 19 with astronauts Walter Schirra and Thomas Stafford aboard (15Dec65)

Astronauts

The following astronauts flew on the 10 manned Gemini missions:

From Astronaut Group 1
Astronaut Service Mission
Leroy Gordon Cooper, Jr. USAF Gemini V
Virgil Ivan "Gus" Grissom USAF Gemini III
Walter Marty Schirra, Jr. USN Gemini VI-A
From Astronaut Group 2
Astronaut Service Mission
Neil Alden Armstrong Civilian Gemini VIII
Frank Frederick Borman II USAF Gemini VII
Charles "Pete" Conrad, Jr. USN Gemini V, Gemini XI
James Arthur Lovell, Jr. USN Gemini VII, Gemini XII
James Alton McDivitt USAF Gemini IV
Thomas Patten Stafford USAF Gemini VI-A, Gemini IX-A
Edward Higgins White II USAF Gemini IV
John Watts Young USN Gemini III, Gemini X
From Astronaut Group 3
Astronaut Service Mission
Edwin Eugene "Buzz" Aldrin USAF Gemini XII
Eugene Andrew Cernan USN Gemini IX-A
Michael Collins USAF Gemini X
Richard Francis Gordon, Jr. USN Gemini XI
David Randolph Scott USAF Gemini VIII

Crew selection

Deke Slayton as head of the Astronaut Office had the main role in the choice of crews for the Gemini program. This selection process, with the prospect of more ambitious missions that would follow with Apollo, became even more political than in the Mercury Program. With Gemini it became a procedure that each flight had a primary crew and backup crew and that the backup crew would rotate to primary crew status three flights later. Slayton also intended for first choice of mission commands to be given to the four remaining active astronauts of the Mercury Seven, Alan Shepard, Gus Grissom, Gordon Cooper and Wally Schirra. John Glenn had retired from NASA in January 1964 and Scott Carpenter, who was blamed by some in NASA management for the problematic reentry of Aurora 7, was on leave to participate in the Navy's SEALAB project and was grounded from flight in July 1964. Slayton himself continued to be grounded due to a heart problem.

In late 1963, Slayton selected Alan Shepard and Thomas Stafford for Gemini 3, James McDivitt and Ed White for Gemini 4, and Wally Schirra and John Young for Gemini 5 (the first Agena rendezvous mission). Gemini 3 was backed up by Gus Grissom and Frank Borman, who were also slated for Gemini 6, the first long-duration mission. Finally Pete Conrad and James Lovell were assigned as the backup for Gemini 4.

Delays in the production of the Agena Target Vehicle caused the first rearrangement of the crew rotation. The Schirra and Young mission was bumped to Gemini 6 and they now were the backup crew for Shepard and Stafford. Grissom and Borman now had their long-duration mission assigned to Gemini 5.

The second rearrangement occurred when Alan Shepard developed Meniere's disease, an inner ear problem. Gus Grissom was moved to command Gemini 3. Slayton felt that Young was a better personality match with Grissom and switched Stafford and Young. Finally Slayton tapped Gordon Cooper to command the long-duration Gemini 5. Again for reasons of compatibility he moved Pete Conrad from being the backup commander of Gemini 4 to be the pilot of Gemini 5, and Frank Borman to the backup command of Gemini 4. Finally he assigned Neil Armstrong and Elliot See to be the backup crew for Gemini 5.

The third rearrangement of crew assignment occurred when Deke Slayton felt that Elliot See wasn't up to the physical demands of EVA on Gemini 8. He reassigned Elliot See to be the prime commander of Gemini 9 and put Dave Scott as pilot of Gemini 8 and Charles Bassett as the pilot of Gemini 9.

The fourth and final rearrangement of the Gemini crew assignment occurred after the deaths of Elliot See and Charles Bassett in a plane crash in St. Louis. The backup crew of Tom Stafford and Eugene Cernan was moved up to become the new prime crew of Gemini 9. James Lovell and Edwin "Buzz" Aldrin were moved from being the backup crew of Gemini 10 to be the backup crew of Gemini 9. This cleared the way through the crew rotation for Lovell and Aldrin to become the prime crew of Gemini 12. Along with the deaths of Grissom, White, and Chaffee in the fire of Apollo 1, this rearrangement is what finally determined the makeup of the early Apollo crews. These events were decisive in determining who would be in position to first walk on the Moon.

In his autobiography Deke! Slayton relates that he would probably have replaced Aldrin with Eugene Cernan, the backup pilot for Gemini 12, if the second flight of the AMU had flown on Gemini 12.

Missions

There were 12 Gemini flights, including two unmanned flight tests. All were launched by Titan II rockets.

Unmanned

Manned


Gemini-Titan launches and serial numbers

The Gemini-Titan launch vehicles, like the Mercury-Atlas vehicles before them, were ordered by NASA through the U. S. Air Force and were in reality missiles. The Gemini-Titan II rockets were assigned U.S. Air Force serial numbers, which were painted in four places on each Titan II (on opposite sides on each of the first and second stages). U.S. Air Force crews maintained Launch Complex 19 and prepared and launched all of the Gemini-Titan II launch vehicles.


Gemini 6A launch. USAF serial number location on Titan II.
Gemini 6A launch. USAF serial number location on Titan II.

The USAF serial numbers assigned to the Gemini-Titan launch vehicles are given in the tables above. Fifteen Titan IIs were ordered in 1962 so the serial is "62-12XXX", but only "12XXX" is painted on the Titan II. The order for the last three of the fifteen launch vehicles was cancelled on 30 July 1964, and they were never built. Serial numbers were, however, assigned to them prospectively: 12568 - GLV-13; 12569 - GLV-14; and 12570 - GLV-15.

All Gemini Launches from GT-1 through GT-12.

Current location of hardware

Spacecraft

Gemini 1 - Destroyed

Gemini 2 - U.S. Air Force Space Museum, Cape Canaveral Air Force Station, Fla.

Gemini III - Grissom Memorial, Spring Mill State Park, Mitchell, Ind.

Gemini IV - National Air and Space Museum, Washington D.C.

Gemini V - Johnson Space Center, NASA, Houston, Texas

Gemini VI - Oklahoma History Center, Oklahoma City, Okla.

Gemini VII - Stephen F. Udvar-Hazy Center, Chantilly, Va.

Gemini VIII - Armstrong Air and Space Museum, Wapakoneta, Ohio

Gemini IX - Kennedy Space Center, NASA, Cape Canaveral, Fla.

Gemini X - Kansas Cosmosphere and Space Center, Hutchinson, Kan.

Gemini XI - California Museum of Science and Industry, Los Angeles, Calif.

Gemini XII - Adler Planetarium, Chicago, Ill.

Trainers

Gemini 3A - St. Louis Science Center, St. Louis, Mo.

Gemini MOL-B -US Air Force Museum, Wright-Patterson Air Force Base, Dayton, Ohio

Gemini Trainer - US Space & Rocket Center, Huntsville, Ala.

Gemini Trainer - Goddard Space Flight Center (Visitor Center), NASA, Greenbelt, Md.

Gemini Trainer - Louisville Science Center, Louisville, Ken.

6165 - National Air and Space Museum, Washington D.C. (not on display)

El Kabong - Kalamazoo Air Museum, Kalamazoo, Mich.

Gemini Trainer- Kalamazoo Air Museum, Kalamazoo, Mich.

TTV-2National Museum of Scotland, Edinburgh, Scotland

Trainer - Pate Museum of Transportation, Fort Worth, Texas

MSC 313 - Private residence, San Jose, Calif.

Rogallo Test Vehicle - Space Harbor, White Sands, N. M.

TTV-1 - Stephen F. Udvar-Hazy Center, Chantilly, Va.

unnamed - U.S. Air Force Space Museum, Cape Canaveral Air Force Station, Fla.

unnamed - U.S. Air Force Space Museum, Cape Canaveral Air Force Station, Fla.

Trainer - U.S. Astronaut Hall of Fame, Titusville, Fla.

MSC-307 - USS Hornet Museum, Alameda, Calif.

See also

External links

Archival Materials:

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Published - July 2009














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