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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Advanced Gemini | 4/5 | https://en.wikipedia.org/wiki/Advanced_Gemini | reference | science, encyclopedia | 2026-05-05T12:50:41.219775+00:00 | kb-cron |
Using the Gemini spacecraft for a crewed Lunar landing was considered as early as the original Mercury Mark II proposal which led to the Gemini program. The initial proposal was for a Lunar orbit rendezvous mission, using a Gemini spacecraft and a lightweight, open cockpit lander, launched by a Saturn C-3 rocket. It was the first time that Lunar orbit rendezvous was proposed as part of a lunar landing concept. The spacecraft would have been tested in Low Earth orbit before the Lunar missions, using two Titan II launches. The lander, which was designed by NASA's Langley Research Center, would have had a mass of no more than 4,372 kilograms (9,639 lb). Some of the proposals had a mass as low as 1,460 kilograms (3,220 lb), with cryogenic propellants being used in place of heavier hypergolic propellant. The proposal was intended to provide a faster and lower-cost alternative to the Apollo program, which was at that time proposing a direct ascent landing. Another proposal would have used a Saturn V to achieve a direct ascent mission profile. The spacecraft consisted of four modules. The Retrograde Module would have been powered by an RL10 engine, and used to propel the spacecraft during the trans-lunar coast. During landing, it would be used for the initial phases of powered descent. At an altitude of 1,800 metres (5,900 ft) above the Lunar surface, the RM would have been jettisoned, and a second module, the Terminal Landing Module, would have performed the final descent. After landing, the spacecraft would have stayed on the Moon for a day, before it was propelled back to Earth. Launch from the Lunar Surface and trans-Earth injection would have been performed by the Service Module, which would also have contained components of the life support system, and other systems which were located in the Equipment Module of the Earth orbit Gemini spacecraft. The Reentry Module was based on the Gemini capsule, but would have been modified to allow it to reenter the atmosphere at the higher velocity that would have been required by a lunar flight. It was seen as the last effort by NASA managers and engineers who still advocated the direct ascent mission profile, and was intended to be cheaper, faster and safer than the Apollo lunar orbit rendezvous technique.
=== Apollo rescue ===
Due to the risks associated with the Lunar landing, several rescue spacecraft were proposed, to be used to allow the crew of an Apollo mission to return to Earth safely in the event of a problem. Many of these designs were based around the Gemini spacecraft. One of these proposals was the Gemini Lunar Orbit Rescue Vehicle, which was designed to retrieve the crew of an Apollo spacecraft stranded in orbit around the Moon. It was to have used a stretched reentry module to accommodate the three astronauts who would have been aboard the Apollo. This would have been attached to a modified Equipment Module. The Equipment Module contained engines which would be used for Lunar orbit insertion and trans-Earth injection, as well as life support equipment to keep the crew alive until they returned to Earth. Launch and trans-Lunar injection would have been performed by a Saturn V. Once the spacecraft was in Lunar orbit, the Apollo crew would have boarded it by means of an EVA. Another proposed spacecraft, the Gemini Lunar Surface Survival Shelter, was designed to be sent to the Moon ahead of an Apollo mission. It would have landed close to the planned Apollo landing site, and if the Apollo Lunar Module's ascent stage failed to ignite, the crew would have performed an EVA to transfer to the LSSS. The shelter was not designed to take off again after landing, so an LSRS or another Apollo mission would then be sent to collect the crew, while the Command Module Pilot of the original Apollo mission would have returned to Earth alone aboard his spacecraft. It consisted of a Gemini Reentry Module, which would have housed the astronauts while they awaited rescue, and a descent stage containing life support systems, consumables, and the engine and propellant used to land the spacecraft. The Gemini Lunar Surface Rescue Spacecraft was intended to fly a direct ascent mission, launched by a Saturn V. Descent stages, built from either the descent stage of the Apollo Lunar Module, or from the Apollo Service Module, would have reduced the spacecraft's velocity as it approached the Moon. One configuration used two Service Modules and one LEM descent stage, with the LEM descent stage performing the final landing, and then being reused for ascent from the Lunar surface and trans-Earth injection. The other configuration used three LEM descent stages, with the second being used for landing and the third for ascent and TEI. The LSRS would have landed close to the Apollo Lunar Module on the Moon, and the Apollo crew would have transferred to it by EVA. Following the Apollo 1 fire in January 1967, NASA conducted a safety review of the Apollo program. In response to this review, McDonnell proposed the Universal Lunar Rescue Vehicle, a repackaged version of the Lunar Surface Rescue Spacecraft with an enlarged capsule to make room for the three astronauts who were being rescued. It was intended to rescue an Apollo crew at almost any point while they were at the Moon, should an anomaly occur. Some ULRV designs included five seats, with two astronauts piloting it to the Moon. The proposal was considered, but rejected due to lack of funds.
== Other proposals ==