Circumlunar Gemini had some fans at then-MSC, as well as at headquarters. It was, in the final analysis, deemed too much of a stunt that would detract from (and steal funds from) Apollo, but had the Soviet Union shown signs in mid-1966 of launching a Zond manned circumlunar flight in the near future, I bet circumlunar Gemini would have been given a green light.It was actually pretty simple -- the Titan II was capable of launching a Gemini heavy enough for the mission (the biggest weight gain was a beefed-up heat shield), and a Centaur had enough kick to put that stack into a free-return trajectory. Put a Target Docking Adapter on the Centaur, rendezvous with it, and burn TLI.Pete Conrad pushed strenuously for this mission for Geminis 11 and 12, and was ultimately shot down. Some say he was given the 1,400-km-apogee maneuver with the Agena as a consolation prize.Now, the follow-on proposal by McDonnell, to develop a small lander and use a combination of a Saturn IB (to launch the Gemini and the lander to LEO) and a Titan IIIC/Transstage (launching the transstage as a rendezvous target for the Gemini/Lander in LEO and providing TLI, LOI and TEI propulsion) to accomplish a one-man lunar landing by the end of 1967, was perhaps technically possible, but stood no chance of being approved. It too directly tried to usurp Apollo's mission, and also would have required a super-fast one-man lander development program that there was simply no funding for.With both lunar applications out the window, I guess McDonnell felt that Big G was their last chance to propose a Gemini variant that would keep them in the manned spaceflight business for another decade or more.
Quote from: the_other_Doug on 05/27/2015 04:12 amCircumlunar Gemini had some fans at then-MSC, as well as at headquarters. It was, in the final analysis, deemed too much of a stunt that would detract from (and steal funds from) Apollo, but had the Soviet Union shown signs in mid-1966 of launching a Zond manned circumlunar flight in the near future, I bet circumlunar Gemini would have been given a green light.It was actually pretty simple -- the Titan II was capable of launching a Gemini heavy enough for the mission (the biggest weight gain was a beefed-up heat shield), and a Centaur had enough kick to put that stack into a free-return trajectory. Put a Target Docking Adapter on the Centaur, rendezvous with it, and burn TLI.Pete Conrad pushed strenuously for this mission for Geminis 11 and 12, and was ultimately shot down. Some say he was given the 1,400-km-apogee maneuver with the Agena as a consolation prize.Now, the follow-on proposal by McDonnell, to develop a small lander and use a combination of a Saturn IB (to launch the Gemini and the lander to LEO) and a Titan IIIC/Transstage (launching the transstage as a rendezvous target for the Gemini/Lander in LEO and providing TLI, LOI and TEI propulsion) to accomplish a one-man lunar landing by the end of 1967, was perhaps technically possible, but stood no chance of being approved. It too directly tried to usurp Apollo's mission, and also would have required a super-fast one-man lander development program that there was simply no funding for.With both lunar applications out the window, I guess McDonnell felt that Big G was their last chance to propose a Gemini variant that would keep them in the manned spaceflight business for another decade or more.The Apollo LEM ran into a fair amount of schedule slip. I'd wager that all lander designs suffered from an overly optimistic schedule in the mid 60s. Had the one person lander and Gemini been given the go ahead they might very well have been in the position of waiting for the lander like Apollo did. Even worse they might not have been able to build it light enough to fly. The LEM at around 14 or so tones was already stretched pretty thin.Many of the one person lander were also not enclosed and pressurized instead relying on the astronaut's space suit. As Allen Bean said once if you threw up in the suit while trying to land you would likely die. So that was a much more risky approach. Two people on the surface also allowed for a reasonable chance that if one should become incapacitated the other could get them back to safety in the LEM. The lander would also be a lot less capable than the LEM. Just being barely capable of getting one person to the surface the amount of science it could do on the surface would have been very limited. Even more so because there would have been only one person. Apollo did do the job of landing before 1970, so the Gemini lander scenario wouldn't have that over Apollo. I'm not sure it could have been done cheaply enough to have been sustainable. It was quite a bit more risky, had little room for growth, and had less capability. NASA would have been just as likely if not even more so to want to finish the program and move on to the shuttle.
Exactly. You very clearly described why lunar Gemini was, in the final analysis, dismissed as a stunt -- worse, a dangerous stunt that would have left us *barely* satisfying the end-of-decade goal, while allowing little to no ability to take advantage of the landing scientifically. (Also, note that lunar Gemini and its drawbacks, as you described it, also rather well describes the Soviet lunar landing system of the late '60s, too. You do the math... )
SIX-MAN APOLLO SPACECRAFTFor those alternative space plans in which the shuttle operationwould be delayed or in which there would be no shuttle, a six-man modifiedApollo spacecraft would be used. This vehicle would have a grossweight of 20,000 ib, a development cost of $1 billion, a first-unit costof $300 million, and a launch-operations cost of $73 million.
RanulfC, you don't have to use quotation marks unless you're quoting somebody.
My Big Gemini article is now published in Spaceflight magazine. Go buy a copy. Lots of Big G goodness.
Quote from: Blackstar on 10/07/2015 06:43 pmMy Big Gemini article is now published in Spaceflight magazine. Go buy a copy. Lots of Big G goodness.I went ahead and purchased this issue online and read through your article today. Excellent work. Would you be willing to share your reference material that you used in L2 sometime in the future?