More Declassified Drawings of Manned Orbiting Laboratory (Dorian)

Copyright © 2014 by Thomas Gangale
@ThomasGangale

Although it is fascinating to see the recently declassified Dorian/Manned Orbiting Laboratory drawings, a problem with their piecemeal release is that they lack context. Obviously they are from briefing slides to senior management, but do they reflect what was actually in development or what the source of the slide show was pitching to senior management in the hope of getting funding to develop? In my view, the released drawings reflect the latter: concepts that might have been but never were. The lack of context includes that temporal component; there are no dates on these images, thus the analyst is left to deduce their place in the history of the MOL program. The evidence suggests that the drawings come from several different periods in the development of MOL.

My first impression of the Dorian_13.jpg drawing is that it was a very early Manned Orbiting Laboratory design, just after Secretary of Defense Robert McNamara canceled Dyna-Soar and announced the MOL program in December 1963. Previously, it was a concept called the Manned Orbital Development System. This drawing may be of MODS on its journey to evolving into MOL. It should be noted that the image does not bear the "Byeman" and "Dorian" markings, which suggests that the drawing dates from a time before MOL became a Byeman program under the Dorian caveat.

Notice that there is no habitable laboratory module and no crew access tunnel; thus, apparently, the crew would have remained in the Gemini for the entire mission. According to the caption, this would have been 60 days. We know from later human spaceflight experience that that it would have been unhealthy for the crew to sit in their seats without exercise for 60 days; that also had to be a real concern even in 1964, if only because this was far beyond the experience of US aerospace medicine (Mercury-Atlas 9 had spent only 1.5 days in orbit).

However, it is not obvious from the drawing that the crew would have had any mission role other than docking this Resupply Vehicle to whatever vehicle it was intended to resupply; it might have performed the docking, then detached the Gemini to return to Earth after a few days or even hours. The man-in-the-loop may have existed in the Resupply Vehicle concept only because the US was not developing an automated docking system, as the Soviets were for Soyuz. An interesting question is whether the intended docking target was a manned or unmanned vehicle. If it were a manned vehicle, there might have been a crew swap, but it would have required extra-vehicular activity (EVA), since the Resupply Vehicle had no docking tunnel; that was still under development as part of the Apollo program.

Comparing the Dorian_13.jpg and Dorian_20.jpg drawings suggest commonality of concept, although they are not conclusive evidence of commonality of design. The Dorian_20.jpg image bears the same security markings, "Secret - Special Handling" rather than "Byeman" and "Dorian," suggesting a close connect in time early in the MOL program. The film path in the two images is the same, looping through six reentry vehicles, while the fact that the RVs themselves are canted in one drawing and not in the other apparently reflects an evolution in design. It is not clear whether this unmanned vehicle was the intended docking target of the manned Resupply Vehicle, or was an unmanned resupply vehicle for some other target vehicle.

The size of the manned Dorian_13.jpg and unmanned Dorian_20.jpg vehicles suggests a Titan IIIC launch vehicle rather than the later Titan III-M, which is additional evidence that these are early drawings. The Dorian_13.jpg image shows an estimated weight of 28,400 pounds. The payload capacity of the Titan IIIC from the Cape to a 28-degree low Earth orbit was 28,900 pounds. The payload capacity of the earliest Titan IIIDs from Vandenberg to a high inclination low Earth orbit was about 25,100 pounds. The facts suggest that the system was being designed for an Eastern Test Range launch, and that MOL was later reoriented for a Western Test Range launch.

The 800px-KH-10_Dorian.jpg image suggests evolution of the MOL concept from the Dorian_13.jpg and Dorian_20.jpg drawings. It is marked "D Secret Special Handling," the "D" probably indicating "Dorian." The core of the program was now a Rendezvous Initial Vehicle (RIV), launched unmanned, containing a habitable module and a section behind it, which although unidentified was undoubtedly the KH-10 camera and the film return vehicles. The crew was to arrive in a separate Rendezvous Resupply Vehicle (RRV), whose outward appearance duplicated the earlier Resupply Vehicle in the Dorian_13.jpg drawing, but now included a hatch in the Gemini heat shield and a crew transfer tunnel. It was a very, very long crew transfer tunnel, an ergonomically hideous design, compared to the final MOL configuration that integrated the Gemini and the Laboratory Module/Mission Module.

The 800px-KH-10_Dorian.jpg image shows the RIV and the RRV docked, with the crew able to cross the docking interface via a tunnel, much like between the Apollo Command/Service Module and the Apollo Lunar Module, yet also shows the possibility of subsequent RRVs exchanging crews via EVA during a rendezvous with no provision for docking these subsequent RRVs. This is an outstandingly clumsy solution, which suggests that design ideas were still fermenting. A much better approach would have been the Multiple Docking Adapter that later was part of the Skylab design.

Of course, the dream of a resuppliable military space station died early on as the result of a turf battle between DOD and NASA. NASA was adamantly opposed to it since its own concepts for evolving a space station from Apollo/Saturn hardware were nearly as old as the Apollo and Saturn programs themselves. A 5 December 1961 NASA document indicates a "wet-launched" laboratory module outfitted from the Saturn C-1's S-4 upper stage, which would be visited by two Apollo crews. The document contemplated a total of six such S-4 wet workshops and 14 Apollo crews. The problem was selling concurrent civilian and military space station programs to Congress; despite their very different missions, they could not help but be viewed as duplicative efforts, only one of which would Congress be willing to fund. NASA won the turf battle within the Executive Branch; MOL was downscoped to a series of expendable platforms that would not be resupplied and would not be revisited, thus it was a "laboratory" and not a "space station."

An intriguing speculation is whether the MOL program did design a multiple docking adapter before the turf battle was settled, and even more intriguing, whether the Skylab MDA was a direct legacy of MOL. The Skylab MDA contractor was Martin Marietta, which was also the builder of MOL's Titan launch vehicle, which is not a compelling link in itself. But it should be considered that there is no obvious reason, in the context of Apollo/Saturn hardware, why the Skylab MDA was 10 feet in diameter, whereas this dimension makes perfect sense in the context of MOL and Titan, both of which were 10 feet in diameter. Transferring the MDA design from MOL to the Apollo Applications Program might have been included as a sweetener in the DOD deal to buy NASA's support for MOL within the Executive Branch's bureaucracy. Indeed, given that Skylab's Airlock Module was built by McDonnell Douglas and included a Gemini hatch, one wonders whether the much narrower Skylab Airlock Module also originated with McDonnell Douglas's MOL. Was it an evolution from the MOL crew transfer tunnel?

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