Space The Gemini Program: From Mercury to Apollo

Even before Major John Glenn performed his first US manned flight in orbit, as part of the Mercury program, NASA, on December 7, 1961, announced a plan to extend the existing manned space flight program through the development of a two-man spacecraft. That program officially was designated 'Gemini', after the constellation Gemini, the Twins and third of the zodiac like by reference to two-man crew of the program, on January 3, 1962, as its original name was the Mercury Mark II project. The major objectives assigned to the Gemini program were clear-cut, like the ones of Projet Mercury had, like to subject two men and supporting equipment to long duration flights up to two weeks (which was a requirement for projected later missions to Moon or deeper space), to perform 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. The Gemini Program seemingly was conceived once US President Kennedy had initiated the US Moon program in May 1961 and that it had became evident to NASA officials that an intermediate step was required between Project Mercury and the Apollo Program. The Gemini program was managed by the Manned Spacecraft Center, Houston, Texas, under direction of the Office of Manned Space Flight of NASA, as Dr. George E. Mueller, Associate Administrator of NASA for Manned Space Flight, served as acting director of the Gemini program and William C. Schneider, Deputy Director of Manned Space Flight for Mission Operations, served as Mission Director on all Gemini flights beginning with Gemini V. The spacecraft to be used by the Gemini program was a enlargement of the familiar Mercury capsule. Engineering changes simplified maintenance and made it more maneuverable for the pilots. Gemini spacecraft were built in St. Louis and astronauts routinely travelled to the city for simulator time. As far as the launcher was concerned, the Titan-II rocket, more powerful than the Redstone, placed the larger spacecraft into orbit. Sometimes referred to as Gemini-Titan for the craft and its launch vehicle, each flight was designated by a Roman numeral. Only the first capsule was nicknamed as Command Pilot Virgil Grissom called it the Molly Brown in reference to his Mercury spacecraft that sank. The Gemini program may be considered both like a series of answers to the first space premieres which kept being performed at the time by the Soviets and like the program which laid the groundworkd for the next phase of the US space exploration, namely, the Apollo program which was to reach Moon. Experience during spacewalks in orbit around the Earth, proved valuable in preparing for lunar extravehicular activities, better known as moonwalks. One of the lasting benefits of NASA's Gemini Program was its sustained technological investments accumulated over a two-year period which eventually laid the groundwork for long-duration missions up to nowadays. The Gemini Program sought to test astronauts’ ability to fly long-duration missions in space, understand how spacecraft could rendezvous and dock in orbit around the Earth, perfect re-entry and landing methods, and further understand the effects of longer space flights on astronauts

a Gemini-Titan spacecraft on the launch pad in 1964, illuminated by pad lights and spotlights. picture site 'Amateur Astronomy' based upon a picture NASA

The Gemini program involded 12 flights, including two first which were unmanned test ones, as it unfolded from April 1964 to November 1966. A brief summary of the Gemini flight results reveals how successful the Gemini Program was. All of the major objectives were met as well as many other objectives assigned to each mission, with the exception of land landing which was canceled from the Gemini Program in 1964. However, the precision control necessary to achieve the land landing objective was demonstrated. Both first flights, like said, of the Gemini program, the Gemini I and Gemini II were unmanned test flights. Both launched atop a Titan-II rocket from the Cape Canaveral launch pad LC-19. Gemini I served to demonstrate the Titan-II and Gemini capsule performance until to the orbit, to flight qualification of operational procedures and subsystems both for the vehicles, prelaunch and launch crews and facilities, and launch and tracking networks and personals. That first flight, in April 1964, proved successfull in terms of orbital test of the Titan-II launch vehicle, spacecraft structural integrity and launch vehicle spacecraft compatibility. No plan had been made to recover the capsule and mission terminated after 3 orbits with the spacecraft disintegrating 3.5 days after launch. The Gemini II flight, in January 1965, a suborbital flight only, was dedicated to demonstrate reentry heat protection during reentry, the structural integrity of spacecraft, a satisfactory performance of major subsystems, checkout and launch procedures and evaluate backup guidance steering signals through launch. Also were scrutinized fuel cell and reactant supply, cryogenics, and communications systems. Flight qualification for both the launcher and craft, from the countdown to the orbit, also were augmented by that flight along with more training for flight controllers and ground communications tracking system qualification. All of the mission objectives were achieved, the fuel cell test excepted as the latter deactivated before liftoff. Launch of Gemini II, on a other hand, did not go without troubles as the Titan-II/Gemini launch vehicle had to be shielded from from 2 hurricanes in August and September of 1964. First stage only was taken down in August as the whole launch stack in September as the latter eventually was definitively re-erected on Sep. 12, 1964 for a launch scheduled Dec. 9, 1964. As first stage engines were ignited howevever the Titan-II Malfunction Detection System detected technical problems due to a loss of hydraulic pressure and shutdown the engines about one second after ignition. Gemini II landed by 16° 36' North Latitude and 49° 46' West in the Atlantic ocean and the landing missed by 40 miles (62.9 km) the planned landing point

Flight	Payload	Altitude	Orbit Inclination	Number of Orbits	Flight Duration	Distance	Launch Date	Landing Date
Gemini I	na	173NM x 87NM (320km x 160.3km)	na	64	4 days	na	April 8, 1964 11:00:01.69 am EST	April 12, 1964
Gemini II	Gemini-II capsule	92.4NM (171.1km)	na	a suborbital flight only	18 min, 16 seconds	1848NM (3422.4km)	January 19, 1965 9:03:59.861 am EST	January 19, 1965 9:22:14

click to a series of pictures illustrating the Gemini program!

Following 10 flights were manned ones as a second and a third (then a fourth in 1964) generations of astronauts had been selected and trained by NASA. A large number of astronauts of the Gemini program were to be seen back with the Apollo one, of them the three crewmembers of the Apollo 11 mission which landed man at Moon. Those flights which all featured a two-man crew, included increasing to 13 days the presence of a manned crew in orbit, performing the first ever US spacewalk, first US space rendezvous then first docking with a other spacecraft. First docking to a orbital target -a Agena rocket stage- was marred on March 16th, 1966 as the Gemini capsule entered a uncontrollable spin with the crew forced to undock and perform a emergency landing

Flight	Dates	Crew	Duration	Remarks
Gemini III (capsule dubbed 'Molly Brown')	March 23, 1965	Virgil I. Grissom, John W. Young	4h 52m 31s	First manned Gemini flight, three orbits. First flight in which the astronauts could change their spacecraft's orbit. Stationed on Kauai, Hawaii during the Gemini 3 mission in as capsule communicator (CAPCOM), Neil Armstrong, the astronaut who was to turn the first man to walk on Moon, helped the crew through their reentry preparations
Gemini IV	June 03-07, 1965	James A. McDivitt, Edward H. White II	4d 1h 56m 12s	The longest US manned space flight at the time, as it also included the first US spacewalk, performed by White and lasting 22 minute
Gemini V	August 21-29, 1965	L. Gordon Cooper, Jr., Charles Conrad, Jr.	7d 22h 55m 14s	First use of fuel cells for electrical power, guidance and navigation system for future rendezvous missions evaluated. 120 orbits completed. During the summer of 1965, the United States began to pull even in the space race with the Soviet Union and the eight-day Gemini V endurance mission doubled America's spaceflight record set two months earlier. It also tested technology that would help make longer missions possible in the future, allowing astronauts to meet the challenges for landing on the Moon and even laying the groundwork for long-duration missions aboard the International Space Station, for example. Gemini V astronauts Cooper and Conrad also were the first to design a insignia patch for their flight. A lesson learned from Gemini V was that flying in the heavier spacesuits was very debilitating and NASA allowed to develop a lightweight pressure suit in a very short time. It was very convenient because the crew could get out of it. Since the Gemini V mission, the crew were tasked to design a mission patch for their mission, a tradition which lasted until now
Gemini VII	December 04-18, 1965	Frank Borman, James A. Lovell, Jr.	13d, 18h, 35m 1s	as the Gemini VI had been scrubbed due to the Agena target for rendezvous and docking failed, Gemini VII was used for the rendezvous instead. Primary objective was to determine whether humans could live in space for 14 days. check a tutorial about the Gemini VII-VI rendezvous
Gemini VI-A	December 15-16, 1965	Walter M. Schirra, Jr., Thomas P. Stafford	1d 1h 51m 24s	1st US space rendezvous accomplished with the Gemini VII capsule. Station-keeping lasted for over 5 hours at distances from 1 to 295 ft (0.3 to 90 m)
Gemini VIII	March 16, 1966	Neil A. Armstrong, David R. Scott	10h 41m 26s	1st docking with another space vehicle, a unmanned Agena rocket stage. Because of problems with the Gemini spacecraft control system, the crew was forced to undock after approximately 30 minutes, as the spacecraft-target vehicle combination had begun to encounter increasing yaw and roll rates. The crew regained control of their spacecraft by using the reentry control system (RCS), and the decision was made in Mission Control to follow mission rules that dictated once the RCS was activated, the crew must be brought home. The Gemini VIII landed early in a secondary landing area in the Pacific
Gemini IX-A	June 03-06, 1966	Thomas P. Stafford, Eugene A. Cernan	3d 21h	Gemini IX provided NASA with further experience for advancing the Apollo program. The original Gemini IX command pilot was scheduled to be Elliot See, with Charles Bassett as pilot but they were both killed on Feb. 28, 1966, when their T-38 jet crashed into the McDonnell Aircraft plant in St. Louis, where assembly of their spacecraft was being completed. The Agena target failed to reach orbit and NASA had a backup rendezvous target available, the 'Augmented Target Docking Adapter,' or ATDA and the mission was redesigned Gemini IXA. The ATDA was launched on June 1, 1966 but it eventually turned a 'angry alligator' as the nosecone shroud had not separate properly. The crew however performed different approaches to rendezvous and assessing how a astronaut could appreciate and calculate a distance to a target. A spacewalk was also performed using a self-contained rocket backpack, called the 'Astronaut Maneuvering Unit,' or AMU which proved few efficient however due to a lack of hand and foot holds. 2 hours of spacewalk and 44 orbits were performed
Gemini X	July 18-21, 1966	John W. Young, Michael Collins	2d 22h 46m 39s	rendezvous with a Agena target vehicle making use of its propulsion systems and with Gemini VIII target vehicle. Collins performed a 49-minute stand in the hatch (a move currently called 'standup EVA') and a 39-minute spacewalk by which he retrieved a experiment from the Agena. With its first target vehicle, the Gemini X pushed upward to a record 475 mile altitude, the highest any humans had traveled at the time. 43 orbits completed
Gemini XI	September 12-15, 1966	Charles Conrad, Jr., Richard F. Gordon, Jr.	2d 23h 17 min 8s	that mission established the Gemini record altitude, at 739.2 miles (1,189.3 km) which it reached using the Agena propulsion system once rendezvous and docking performed during first orbit. The mission performed the first simple test of creating artificial gravity by spinning the two craft around their center of mass as Gordon performed two spacewalks totalling 33 minute, and a two-hour stand. 44 orbits. Gemini XI splashed down in the western Atlantic, 700 miles East of Cape Kennedy
Gemini XII	November 11-15, 1966	James A. Lovell, Jr., Edwin E. Aldrin, Jr.	3d 22h 34m 31s	last Gemini flight as it rendezvoused and docked with a Agena target and kept station with it during spacewalks. Aldrin set a record of 5 hours, 30 minutes for one spacewalk and two standing exercises

Gemini 4 was the first flight to be followed by the mission control at the new Manned Spacecraft Center (MSC) in Houston. The MSC grew out of the 'Space Task Group' formed soon after the creation of NASA and originally located at the Langley Research Center in Virginia. Beginning with Project Mercury, that complex was the center of U.S. human spaceflight training and management through Gemini III. The 1,620-acre MSC complex became the primary flight control center for all subsequent U.S. manned space missions from Project Gemini forward. On Feb. 19, 1973, the center was renamed in honor of the late U.S. president and Texas native, Lyndon B. Johnson