NASA Study Summary:"Rendezvous Concept for Circumlunar Flyby in 1967"

Here's an interesting study from July of 1965-- how to use a Gemini-Titan II and a slightly modded Titan IIIC with a pair of transtages to do a lunar flyby mission (not quite Apollo 8, which entered orbit-- the Gemini would only do a free return trajectory ala Apollo 13) in 1967.

This study was predicated on "complementing the Apollo program with space "firsts" to greatly increase our national prestige".

The Titan IIIC would launch first, followed four minutes later by a Gemini launched on a regular Titan II GLV. The Titan IIIC would deliver into orbit, connected to its regular transtage, a second modded transtage 2 that had been stripped of all nonessential equipment and outfitted at the forward end with a TDA (target docking adapter) from the Agena stages that Gemini docked with and performed manuevers. The Gemini would catch up as the transtages entered orbit, and within 3 hours, dock. The spent Transtage 1 would be jettisoned (it was kept mated to the transtage 2 to provide thermal control to prevent fuel line freezing in orbit, and to provide telemetry and station keeping attitude control for the second transtage until the Gemini docked with it and could take over those functions). The Gemini would then, at the proper time, ignite the second transtage for a 400 second burn at 5 gees "eyeballs out" for the translunar injection. Once the transtage 2 had burned out, the Gemini would undock and jettison the transtage, and use its OAMS system for midcourse correction and velocity trim for the lunar flyby along a free return trajectory. Thus we beat the Russians around the moon and all is well with the world!!!

It was an interesting proposal, that might have gotten more traction had Gene Cernan not had so many problems with EVA manuevers on Gemini 9. Gemini was doing well on meeting all the objectives to that point (this report was written about the time of the historic Gemini 4 spacewalk by Ed White in early June 1965 so I'm sure there was a certain amount of pride and optimism which seeps into the report) and might have had the last two flights with "little to do" that hadn't already been successfully accomplished had EVA procedures and methods been perfected before Cernan's troubled EVA on Gemini 9. As it turned out, both Collins on Gemini 10 and Gordon on Gemini 11 improved upon EVA methods, but there were still problems that weren't fully solved until Aldrin's EVA on Gemini 12. The fact that these missions had to focus so much on perfecting EVA meant that there weren't any "leftover" Gemini vehicles to perform the circumlunar mission.

Of course this proposal might not have gained much traction though, as it seems a bit 'desperate' to beat the Russians... the Soviet effort was slowing at just the time the US effort with Gemini was really ramping up and beating them, so it might have been seen as an unnecessary risk... The Soviets would have to have been in a lot better position than they were to really justify such a risk... and if they were, then that would surely have added a lot of impetus to such a mission... just as it did with Apollo 8!

At any rate, it's an interesting "what might have been" had history turned out just a little bit different. As it was, Sergei Korolev died in mid-66, stalling the Soviet lunar effort almost altogether, while Apollo appeared to be going "full speed ahead", until the January 1967 fire that killed the Apollo 1 crew, followed in April by the Soviet disaster of Soyuz one that killed cosmonaut Vladimir Kamarov. I'm sure that at this point, even had the circumlunar Gemini program been approved and nearing operational readiness, there would likely have been a critical rethinking of the mission and risks associated with it and it would have been cancelled.

It's an interesting idea-- essentially drag racing a Titan IIIC and a Gemini Titan II... Wonder if one could get mission points for that?? LOL

Enjoy! OL JR

View attachment NASA Study Summary- Rendezvous Concept for Circumlunar Flyby in 1967.txt

Pic one is the modified Titan IIIC used for the Circumlunar Gemini mission... it was slightly taller with the addition of a second transtage for the TLI burn as payload of the regular Titan IIIC transtage used on ascent, along with a new interstage and a fwd skirt to adapt the TDA to the transtage 2 for the Gemini to dock with transtage 2 for TLI... Other than that, it was a normal Titan IIIC in all respects...


Pic two is transtage 1, which would inject the transtage 2 payload into orbit and remain attached to it, providing telemetry and stabilization/guidance as well as preventing the engines/fuel lines/tanks of transtage 2 from being exposed to space and possibly freezing before the Gemini could dock and perform TLI...


Pic three is an end view of the forward end of transtage 1, showing the stabilization system installed in the fwd skirt equipment section and the fuel tanks located in the rear section behind it...


Pic four is the Gemini launch vehicle (GLV), the standard Gemini-Titan II used on all the Gemini missions, and unmodified for this mission... It would be launched four minutes after the Titan IIIC launched and rendezvous with the transtages at their orbital insertion. If for any reason the Gemini couldn't launch on schedule, the orbital parameters were such that 90 minutes later the transtages would overfly the Cape again and the Gemini could be launched then and rendezvous with the transtages at Gemini orbit insertion...


More to come! OL JR

Pic one is the transtage 2, used for TLI... it was stripped of all nonessential equipment (no equipment section with the guidance and stabilization thrusters, since this was initially provided during orbital insertion and station keeping prior to Gemini docking by the equipment section of transtage 1, and then subsequently provided by Gemini after docking and jettison of transtage 1). This made it capable of delivering enough impulse to propel the Gemini and transtage 2 to TLI...


Pic two is the lunar Gemini stack-- transtage 2 at the left, providing propulsion, with the Gemini and its service module docked to it on the right. The TDA was installed on the transtage using a purpose designed and built conical structure, either of corrugated panels like an inverted thrust structure cone, or of a tubular truss framework (to be determined by further study) to adapt the 10 foot diameter transtage 2 to the 5 foot diameter of the TDA which was designed for the 5 foot diameter Agena stage normally used on the Gemini missions. The Gemini would dock to the TDA which would retract to the 'locked' position, and then at the appropriate time, the Gemini would command the transtage 2 to fire its engines for a 400 second, 5 g, EYEBALLS OUT (being thrown forward against the seatbelts in the Gemini, instead of backwards into the couch) TLI burn... that would have been pretty uncomfortable, but endurable. After the transtage 2 burned out, it would be jettisoned by the Gemini, which would turn around and perform any trim burns necessary to finalize its free-return trajectory around the moon with its OAMS propulsion system. Then it's just coast to the moon, loop around it, and coast back to Earth...


Pic three is the trajectory planned for the heat shield qualification test flight, planned to be performed on a Titan IIIC, much like the Titan III/MOL test flight was. This one would have used a Titan IIIC to loft a Gemini capsule mated to a transtage on a lofted suborbital trajectory to an altitude of about 160 miles or so, igniting for a second burn back down towards Earth to 'drive' the Gemini back into the atmosphere at lunar return velocities (much like Apollo 4 did with the CM for lunar high-speed reentry qualification). This would certify the Gemini heatshield could endure the MUCH higher heating rates from the high speed lunar reentry.


Pic four is a puzzle-- it was attached to the end of the study, but it's clearly NOT *directly* related to the proposals made IN this study-- there was brief mention in the study to the possibility of performing a "single launch direct flight mission" using a Gemini on top of a Titan IIIC LV, much like an MOL was to be launched. This appears to be part of this proposal, but it wasn't labeled or otherwise described. The Titan IIIC and the TLI stage would fly a DIRECT INJECTION flight path (no stopover in a low Earth parking orbit as Apollo did and the 'standard' two-launch Gemini/transtage 2 TLI rendezvous and docking mission as described throughout this report). This graphic shows an apparently heavily modified tank stretched twin engined Transtage providing propulsion to a heavily modified Gemini vehicle (apparently with its service module heavily modified with gull-wing "payload bay doors" that would open to allow access to space for a variety of installed sensor systems for lunar reconnaissance and measurement. The vehicle would still perform a free-return trajectory but would be outfitted and modified to conduct a much more thorough scientific intelligence gathering mission during its lunar flyby than the standard 'prestige' mission outlined in the study. I'm sure the mods to the spacecraft would have been much more expensive and time consuming as well, which sort of negates the need for the mission in the first place, which is probably why it only got cursory discussion in the report...


Still an interesting 'might have been'...

That's all for this one! Later! OL JR

Ya know, it's cool to see all these 'what if's'. I used to play the PC game 'Buzz Aldrin's Race Into Space' back in the day and it was pretty fun to explore all the different ways we tried to get to the moon (LOR, EOR, DA, one-man, two-man,etc).

FC

Yeah, you're right fastcargo... it IS really interesting (and the airbag landing system really proves that there's very little that's truly "new"... just slightly different implementations... )

Ya know, looking at that last pic, any idea what a "negation missile" is on the left gull wing door of the Gemini SM?? I mean, a "nuclear sensor" makes sense-- looking at neutron emissions or something, sure... but a "negation missile"... That last proposal does sort of look like a 'war wagon' of some type... "lets go obliterate the Martians on the moon"??? LOL

Later! OL JR

luke strawwalker said:

Ya know, looking at that last pic, any idea what a "negation missile" is on the left gull wing door of the Gemini SM?? I mean, a "nuclear sensor" makes sense-- looking at neutron emissions or something, sure... but a "negation missile"... That last proposal does sort of look like a 'war wagon' of some type... "lets go obliterate the Martians on the moon"??? LOL

Click to expand...

I saw that too! My considered opinion is that they may have been intended for 'impact' studies...ie the crew fires a missile at the moon and observes the impact to analyze the composition of the surface.

But I really have no idea...

FC

FastCargo said:

I saw that too! My considered opinion is that they may have been intended for 'impact' studies...ie the crew fires a missile at the moon and observes the impact to analyze the composition of the surface.

But I really have no idea...

FC

Click to expand...

Interesting... the study made no mention of this... perhaps it's in another study...

That could be a plausible explanation of the "negation missiles"... but I think crashing a spent Centaur stage into the moon while the cameras watch is 'more dramatic'... LOL

Later! OL JR

Here's some more related schematics of a version of a "Lunar Gemini" that was proposed by McDonnell Douglas... This one appears based on the "Blue Gemini" for the Air Force's Manned Orbiting Laboratory, which had a hatch in the heat shield. This "lunar Gemini" seems to be a modification of that craft with a larger Service Module, perhaps to adapt it to the S-IVB stage on a Saturn IB (though I'll have to check up on this). Note it's also fitted with a very "Mercury like" escape rocket...


Pic two is another of the schematics...


Pic three is another schematic... note the right hand astronaut turned around and about to head through the heat shield hatch in the rear of the Gemini capsule in the lower left-hand corner... the top left hand side seems to be a diagram of the latches of the hatch, and to rest seem to relate to the tunnel connecting the heat shield hatch with the rest of the craft...


Pic four is more schematics; these seem to be detailing the capsule and SM layout, and mating to the booster, in this case it appears to be the standard Gemini-Titan II launch vehicle...


Pic five is more of the same...


Later! OL JR

Here's a quick summation of the thinking of McDonnell Aircraft on the possibility of lunar Gemini's... (they even designated such a vehicle "GEMINI L"). This brief document gives a list of possible launch vehicles and mission modes, most involving EOR (like the original summarized proposal) but most utilizing modified equipment and some outright all-new equipment (like a new tanker craft and in-space fuel transfer, which the Russians have done with hypergolic propellants on their Salyut stations about a decade after these proposals were vetted). The launch vehicles used would have included an "uprated" Gemini-Titan II using an unspecified number of (presumably) Delta SRMs strapped onto the first stage, as well as the Titan IIIC/ IIIM LV and even Saturn I and Saturn IB, even a IB with a Centaur third stage for a single-launch Gemini lunar mission...

Interesting stuff... Here's the synopsis...
later! OL JR

View attachment Hammersmith Lunar Gemini Notes.txt

Here's some stuff that came with the previous brief in the last post...
Pic one is a description of the pads and their assignments at the AMR-- Atlantic Missile Range...


Pic two is a description of the available/possible Gemini deep-space TLI propulsion stages and their characteristics...


Pic three is some possible combinations of launch vehicles and upper stages to conduct the Gemini lunar mission...


Later! OL JR

Very interestingstuff.

haven't read it all...but I have to ask.

Could a gemini capsule take a lunar return rentry at 25,000 mph?

Apollo had to rotate and unload the G's and heat to make it back in....

MaxQ said:

Very interestingstuff.

haven't read it all...but I have to ask.

Could a gemini capsule take a lunar return rentry at 25,000 mph?

Apollo had to rotate and unload the G's and heat to make it back in....

Click to expand...

That was brought up in the second study I posted here...

Apparently the heat shield was sufficient, but the shingles on the side of the capsule were, and I quote, "barely adequate as it is for reentry, and will have to be beefed up to withstand the heat load from lunar return velocities" (paraphrased). The study continued to discuss the issue and pointed out several different possibilities to deal with the issue, from insulators applied to the outside of the capsule to ablatives similarly applied, identical to how it was done on Apollo...

The main thing I see on this mission is, you better be darn sure your transtage and guidance system is spot on the money and injects you into a perfect free return trajectory, because basically there's VERY little manuevering delta-V to get back on course or trim the velocity after transtage burnout-- without a true service module and SPS system, big manuevers/burns were out, as was any type of abort-- once you went thru TLI you were committed...

Five gees eyeballs out for several minutes during TLI would've been rather uncomfortable as well...

Later! OL JR

Luke, you gotta write book someday. I always enjoy your posts on topics like this. You rock my man!!!

Lou

loujoe said:

Luke, you gotta write book someday. I always enjoy your posts on topics like this. You rock my man!!!

Lou

Click to expand...

Thanks for the vote of confidence...

Later! OL JR

I agree that reading about "what ifs" is always fascinating, but I do have to wonder - if the stated goal of the US manned space program at that time was to land a man on the moon before the end of the decade, and that Apollo was the chosen route - why were people spending time dreaming this stuff up, not to mention the money being spent?

My opinion is that it was the eqivalent of brainstorming. The idea being to explore all options in case the primary path runs into an insurmountable obstacle.

FC

Rocketcrab said:

I agree that reading about "what ifs" is always fascinating, but I do have to wonder - if the stated goal of the US manned space program at that time was to land a man on the moon before the end of the decade, and that Apollo was the chosen route - why were people spending time dreaming this stuff up, not to mention the money being spent?

Click to expand...

To quote the "Dukes of Hazzard" movie, "Nothing sounds more official than a 'Plan B'"...

It's always good to have a fallback position. Remember at the time, Nothing the size of a Saturn V had ever flown, and there WERE doubters, with legitimate issues... the S-II stage development problems and stuff like that were an issue, plus, Apollo was experiencing a few hiccups along the road around this time IIRC... There was also the UNKNOWN factors in the Soviet program-- we had fairly good intel on thier program, but they caught us off-guard enough that there was still considerable uncertainty... Factor the two together and you have a pretty good reason to have a "Plan B" in your back pocket...

Plus, it's simply natural for companies and people in a certain program to look at ways that their work can be expanded upon, explore the capabilities of what it CAN do rather than just what it IS doing, especially when its completion date is on the horizon and coming closer day by day and when the program is completed everything is canned and everybody is looking for a new job... IF you can find an inventive, attractive enough project that your program is capable of performing, you just might get the go-ahead and morph your program into something new, or something that will continue for some time, and keep it around awhile longer and your present job for a while longer... that's always nice...

Take a look at the plans for Saturn V... even Saturn IB... and Apollo Applications-- a whole series of Skylabs, Saturn IB-capable SLA-cone-shaped "Skylabs" (to do it on the cheap), nuclear TV satellites (SNAP), satellite servicing missions with Apollo, constructing 100 foot diameter parabolic antennas in space with Apollo, etc... all sorts of interesting possibilities out there, and who knows, if you can get NASA HQ to bite and get the money-minders in Congress interested enough to fund it, you've just prolonged the program considerably. Quite true that some of the ideas were probably just brainstorming with no REALISTIC chance of ever being affordable, or of being approved, or even being really desirable or particularly feasible (lots of things are "feasible" if money is NO ISSUE (which it NEVER is not an issue). But even that can give a starting point for other ideas to work from that might be more 'acceptable' or worthwhile...

Remember, Titan III started out with someone saying, "I wonder what would happen if we slapped a couple 10 foot SRMs on either side of a Titan II....??"
So sometimes even stuff that at first blush appears 'crazy' DOES come to pass...

As Mr. Spock used to say, "there are always... POSSIBILITIES...."

Later! OL JR