Project Gemini

• 1. Origins And Objectives

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  In 1961, NASA officials faced a stark reality. The Soviet Union had already sent humans into orbit. Project Mercury had achieved the first American spaceflight, but it was limited to single astronauts and short durations. President John F. Kennedy announced his goal of landing men on the Moon by the end of the decade in May 1961. This ambitious target required capabilities that no existing spacecraft possessed. Jim Chamberlin, head of engineering at the Space Task Group, began work on a bridge program between Mercury and Apollo in February 1961. He presented two initial versions of a two-man spacecraft called Mercury Mark II at a NASA retreat at Wallops Island in March 1961. Scale models were shown in July 1961 at the McDonnell Aircraft Corporation's offices in St. Louis. After Apollo was chartered to land men on the Moon, NASA approved the two-man / two-vehicle program rechristened Project Gemini on the 7th of December 1961. McDonnell Aircraft was contracted to build it on the 22nd of December 1961. The program was publicly announced on the 3rd of January 1962. Its major objectives included demonstrating endurance of humans and equipment for extended periods up to two weeks. It aimed to effect rendezvous and docking with another vehicle. The program also sought to demonstrate Extra-Vehicular Activity or space-walks outside the protection of the spacecraft. Finally, it intended to perfect techniques of atmospheric reentry and touchdown at a pre-selected location on land.

• 2. Spacecraft Engineering Design

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  The Gemini capsule measured approximately 18 feet long and 9 feet wide with a launch weight varying from 5,000 to 7,000 pounds. Unlike Mercury, the retrorockets, electrical power, propulsion systems, oxygen, and water were located in a detachable Adapter Module behind the Reentry Module which would burn up on reentry. A major design improvement in Gemini was to locate all internal spacecraft systems in modular components. These could be independently tested and replaced when necessary without removing other already tested components. Many components in the capsule itself were accessible through their respective small access doors. Gemini used completely solid-state electronics and its modular design made it easy to repair. The emergency launch escape system did not use an escape tower powered by a solid-fuel rocket but instead used aircraft-style ejection seats. Maxime Faget, the designer of the Mercury LES, was less-than-enthusiastic about this setup. He feared the ejection seats might seriously injure astronauts and noted they would only be usable for about 40 seconds after liftoff. The main proponent of using ejection seats was Chamberlin who had never liked the Mercury escape tower. He reviewed several films of Atlas and Titan II ICBM failures to estimate fireball sizes. At higher altitudes where ejection seats could not be used, astronauts returned to Earth inside the spacecraft. The Gemini ejection system was never tested with the cabin pressurized with pure oxygen as it was prior to launch. In January 1967, the fatal Apollo 1 fire demonstrated that pressurizing a spacecraft with pure oxygen created an extremely dangerous fire hazard.

• 3. Astronaut Selection And Training

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  Deke Slayton served as director of flight crew operations with primary responsibility for assigning crews for the Gemini program. Each flight had a primary crew and backup crew rotating to primary status three flights later. Slayton intended first choice of mission commands to go to four remaining active astronauts from the Mercury Seven: Alan Shepard, Grissom, Cooper, and Schirra. John Glenn retired from NASA in January 1964 while Scott Carpenter remained on leave due to an arm injury sustained in a motorbike accident. During training on the Gemini Project, Shepard developed Menière's disease which effectively grounded him until corrective surgery allowed his return with Apollo 14. Sixteen astronauts flew on 10 crewed missions across three groups known as Group 1, Group 2, and Group 3. In late 1963, Slayton selected Shepard and Stafford for Gemini 3 along with McDivitt and White for Gemini 4. Delays in Agena Target Vehicle production caused the first rearrangement of crew rotation. The second rearrangement occurred when Shepard developed Ménière's disease leading to Grissom commanding Gemini 3 instead. The third rearrangement happened when Slayton felt Elliot See was not up to physical demands of EVA on Gemini 8. He reassigned See to be prime commander of Gemini 9 and put Scott as pilot of Gemini 8. Charles Bassett became pilot of Gemini 9 before both died in a trainer jet crash into a McDonnell building holding their capsule.

• 4. Historic Mission Highlights

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  Ten Gemini crews and 16 individual astronauts flew low Earth orbit missions during 1965 and 1966. All were launched by Titan II launch vehicles from Launch Complex 19 at Cape Kennedy Air Force Station in Florida. Gemini 3 marked the first crewed mission carrying Grissom and Young while changing its orbit using thrusters. On the 3rd of June 1965, Ed White became the first American to make an extravehicular activity or spacewalk during Gemini 4. His space walk lasted 22 minutes. Gemini 5 ran from the 21st of August 29, 1965 demonstrating eight-day endurance necessary for lunar missions with first use of fuel cells. Gemini 7 set a 14-day endurance record running the 4th of December 18, 1965. Gemini 6A accomplished the first space rendezvous with its sister craft Gemini 7 in December 1965 station-keeping for over five hours. The crew played Jingle Bells on harmonica and bells as part of a jocular Santa Claus sighting. Gemini 8 achieved first docking with uncrewed Agena target vehicle but suffered near-fatal tumbling due to thruster malfunction before Armstrong effected emergency landing. Gemini 10 established radiation was not a problem while Collins met another spacecraft in orbit during his second successful EVA. Edwin Buzz Aldrin proved useful work could be done outside spacecraft without life-threatening exhaustion during Gemini 12 setting an EVA record of 5 hours and 30 minutes.

• 5. Tragedies And Personnel Losses

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  Three astronauts died in air crashes during training including both members of prime crew for Gemini 9. Elliot See and Charles Bassett were killed when their trainer jet crashed into a McDonnell building holding their capsule in St. Louis. This tragic event forced immediate reshuffling of all remaining assignments. The backup crew of Stafford and Cernan moved up to become new prime crew of Gemini 9A. Lovell and Aldrin shifted from being backup crew of Gemini 10 to become backup crew of Gemini 9. This cleared way through rotation allowing them to become prime crew of Gemini 12. Alongside deaths of Grissom, White, and Roger Chaffee in Apollo 1 fire this final arrangement helped determine makeup of first seven Apollo crews. These losses shaped who would eventually walk on the Moon decades later. Gus Grissom wrote posthumously in 1968 that realization of Mercury's end prompted him to focus efforts on upcoming Gemini program before his own death. The program demonstrated resilience despite these personal tragedies affecting every subsequent mission assignment.

• 6. Military Extensions And Cancellations

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  The United States Air Force planned to use Gemini for Manned Orbital Laboratory or MOL program which was later canceled. A range of applications considered included military flights space station logistics delivery and lunar flights. Some proposals used off-the-shelf spacecraft while others featured modifications carrying more personnel visiting Moon performing other objectives. Blue Gemini project intended crude ground observation practicing rendezvous with suspicious satellites. USAF disliked Navy recovery so they intended eventual airfoil landing on three skids carried over from original design. At first some within NASA welcomed sharing cost with USAF but later agreed NASA better operated alone. Blue Gemini canceled in 1963 by Secretary of Defense Robert McNamara deciding NASA flights could conduct necessary experiments. MOL canceled by Secretary of Defense Melvin Laird in 1969 when uncrewed spy satellites performed same functions much more cost-effectively. In August 1969 Lukas Bingham proposed Big Gemini shuttle up to 12 astronauts to planned space stations. Only AAP project funded was Skylab using existing hardware eliminating need for Big Gemini. McDonnell sought derivative flying cislunar mission achieving crewed lunar landing earlier less costly than Apollo but these rejected by NASA administration.

• 7. Legacy And Cultural Impact

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  From 1962 to 1967, Gemini cost $1.3 billion in 1967 dollars totaling approximately $797 million for spacecraft plus $409 million for launch vehicles. The program left Apollo free to pursue prime mission without developing techniques themselves. It demonstrated superiority over Soviet Union with long duration flight rendezvous and extravehicular capability. Two capsules featured in plot of 1967 James Bond film You Only Live Twice codenamed Jupiter instead of Gemini. Modified one-man capsule sent astronaut played by James Caan to Moon in 1968 film Countdown. Missions 4, 8, and 12 appeared in first episode HBO series From Earth to Moon covering aspects relating Neil Armstrong touched upon in 2018 film First Man. Many episodes television show I Dream Jeannie featured launch pad footage various missions. Gemini layer 7 telecom standard named after missions its non-standard port number 1965 references first mission date. Current locations include National Air and Space Museum Washington D.C., Johnson Space Center Houston Texas, Steven F Udvar-Hazy Center Chantilly Virginia. Fifteen Titan IIs ordered in 1962 but last three canceled the 30th of July 1964 never built though serial numbers assigned prospectively.