In 1961, the Mercury project proved to be insufficient for a lunar landing. The project did not achieve the needs for a lunar landing. Therefore, NASA announced another spaceflight project, the Gemini project.
That technological gap had to be closed. NASA built a bigger version of the Mercury capsule (CM) with a Service Module (SM) below it. The launch vehicle used for this project was a modified Titan II US Air Force missile.
The capsules could support two astronauts for more than two weeks. The power was generated by fuel cells, which were in the SM. Before re-entry, the SM was jettisoned and the crew in the CM went back to Earth.
During the Gemini project, docking in orbit became possible and also EVAs (spacewalks) were performed. All this was needed to achieve a lunar landing.
The first manned Gemini was the only Gemini to carry a name. It was Gemini-Titan III, named Molly Brown. This name refered to Virgil Grissom‘s re-entry after Mercury 4, when the hatch was lost and Grissom nearly drowned after the capsule sunk. The other astronaut was John Young. Gemini-Titan III was launched on 23rd March 1965.
On 3rd June 1965 Gemini-Titan IV was launched. Edward White was on 4th June 1965 the first American to make a spacewalk (EVA). The other astronaut was James McDivitt.
On 21st August 1965, Gemini-Titan V was launched. The astronauts Gordon Cooper and Charles Conrad, were 8 days in orbit. This was the first Gemini which used fuel cells for electrical power.
Gemini-Titan VII was launched on 4 December 1965. The astronauts James Lovell and Frank Borman set a space staying record. Nearly 14 days in Earth orbit. The astronauts met Gemini-Titan VI, which was launched on 15 December 1965 and manned by Walter Schirra and Thomas Stafford. The two spacecraft approached each other by docking maneuvers, but did not dock.
Gemini-Titan VIII with Neil Armstrong and David Scott as the astronauts, was launched on March 16 1966. This spacecraft DID achieve a docking, on a probe which was launched earlier. These docking procedures took also place on March 16 1966, about 6.5 hours after lift-off.
A docking procedure was also accomplished by Thomas Stafford and Eugene Cernan, in Gemini-Titan IX. This mission was launched on 3rd June 1966.
Although the Gemini-Titan IX mission was a success, it was not celebrated. On 28th Febraury 1966, US astronauts Elliott See and Charles Bassett, died in a plane crash. These two astronauts were the prime crew of Gemini-Titan IX. After the crash, Cernan and Stafford became the prime crew, untill that time they were the back-up crew.
On 18th July 1966, John Young and Micheal Collins were launched in Gemini-Titan X. During this mission, EVAs were achieved. Docking manoeuvers were canceled, due to insufficient fuel supplies.
Gemini-Titan XI, was launched on 12 September 1966, with on board the astronauts Charles Conrad and Richard Gordon. During this mission, both spacewalks and docking with a probe were achieved.
The launch of the last Gemini mission took place on 11th November 1966. The astronauts of Gemini-Titan XII were James Lovell and Edwin Aldrin. Both docking and EVAs were achieved in this mission.
The Gemini project was a success. Spacecraft could now dock, spacewalks (EVAs), were not a problem anymore and the spacecraft could support astronauts long enough to attempt a lunar landing. NASA was now ready for the last step towards the Moon, the Apollo project.