Apollo LM&SS: Mapping the Moon and the Earth (Apollo Applications Program, Part III)

lm-ss-cutaway

The later design of the LS&MM. Unlike the earlier, larger module based on the KH-7 satellite, this one’s mapping module (right) was designed by Martin Marietta. As well as the crew compartment shown, an open truss containing the mapping cameras and sensors would be attached where the “End Airlock S016″ can be seen—retrieving the film from the cameras would require depressurizing the compartment and a suited astronaut reaching into space to get it. The section on the left is the usual Apollo CM. Public domain image from NASA document Technical Data AAP Mission 1A 60-Day Study. Click for a larger view.

What it was:  A tiny space station consisting of a photo reconnaissance module docked with an Apollo CSM in place of a regular LM. In return for being unable to land on the Moon, the LM&SS would become the first lunar-orbit space station, its mission to take high-quality photographs as the CSM was orbiting, and do it in a variety ways such as in regular light or infrared. It was originally targeted at the Moon, at first to survey Apollo landing sites and later for a more comprehensive scientific mapping mission. After cancellation and rebirth it turned into an Earth observation mission, partly for scientific study of the globe and partly to test the equipment for what had become a more hypothetical mid-to-distant-future Apollo lunar mapping mission.

Details: One of NASA’s earliest goals was to survey the Moon; there’s not much point in sending out a manned Moon lander if you don’t even know where they can put down safely. This goal was met by five very successful unmanned probes, Lunar Orbiter 1 through Lunar Orbiter 5, launched between August 1966 and August 1967. The first three of these specifically surveyed potential Apollo landing sites, while Lunar Orbiter 4 mapped almost the entire near side and Lunar Orbiter 5 almost the entire far side. Altogether they covered 99% of the Moon’s surface, and the last of the probes even photographed some of the surface down to a 2-meter resolution.

Before they were launched, though, NASA was worried that they might not accomplish what they were built to do—and rightfully so: the Lunar Orbiter’s predecessor, the Ranger program, had become a laughing stock after the first six attempts to get a probe to the Moon had failed. Even though the Rangers had the comparatively simpler goal of crash-landing (and photographing the impact region on the way down), from August 1961 to January 1964 they had done nothing but produce a sorry list of launch failures, camera failures, and outright misses of a target 3475 kilometers in diameter. Ranger 7 finally pulled off the trick on July 28, 1964, smacking into the Moon 69 kilometers from the eventual Apollo 11 landing site on the Sea of Tranquility, but NASA was still nervous about getting the quantity and quality of images they would need to keep an LM from accidentally landing on a boulder or on a steep slope.

So while they pinned their hopes on the Lunar Orbiter program, they also developed a backup plan they could use if they needed it: the Apollo Lunar Mapping and Survey System (LM&SS). At the time the new National Reconnaissance Office, after several years of teething problems themselves, had been building and flying the KH-7 spy satellite successfully since 1963. In the same year the Department of Defense, NASA, and the NRO agreed to share their technology and Kodak, Lockheed, and General Electric were contracted to build a variant of the KH-7 which had its station-keeping engines and film re-entry vehicle deleted but a small docking port added. So modified, one could be lofted into orbit in the part of a Saturn V that would normally house an LM.

kh-7-camera

The camera of a KH-7 satellite, and so a close analog of the original LM&SS. The re-entry vehicle for the film (left) would have been removed and replaced with a docking adapter. Public domain image from the NRO. Click for a larger view.

As with the regular Apollo missions, this one would have been sent on its way to the Moon by the upper stage of the Saturn V and then a short way into that journey the CSM would have undocked, moved away a short distance, rotated 180°, and then returned to dock nose-first—the difference being that it would be docking with the LM&SS, not a more-usual LM.

Upon arrival at the Moon, the LM&SS (which was also the name used for the entire craft) would enter a polar orbit, slicing the Moon up photographically as it rotated beneath. The entire mission would take 35 days, 28 of them in lunar orbit so that the Moon could make one complete turn on its axis and the LM&SS cover the entire surface; this would have required a change to the CSM’s life support systems so it could handle a journey that long.

The film in the camera would be retrieved periodically and then once all the photographs were taken the LM&SS would have been ejected to crash into the Moon (as it would do sooner rather than later because of the way lunar mascons wreak havoc on stable lunar orbits) and the CSM would return to Earth following the usual Apollo mission profile.

This variant KH-7 would have been about five meters long and enclosed entirely in a near-featureless cylinder about a meter and a half in diameter. When docked to the CSM it would have looked, appropriately enough, as if the CSM was sporting an enormous telephoto lens on its nose.

By 1967 an internal battle at NASA between those who felt that the Lunar Orbiter survey was sufficient and those who wanted the higher-resolution LM&SS pictures ended with the former in the ascendant. Four LM&SS modules were at various stages of completion by then, but this particular version of the lunar mapping mission was cancelled.

Among the factors contributing to this was the fact that the mission would have needed a precious Saturn V launch just at the time when NASA were discovering that Congress wouldn’t pay for as many of those rockets as they would have liked. That explains in part the second variant of the LM&SS program, the Apollo Applications Program launch that was designated AAP-1A.

As the name suggests, this would have been an early Apollo Applications Program mission—the third, confusingly enough, after AAP-1 and AAP-2 which would have launched the proto-Skylab Orbital Workshop space station and its first crew. AAP-1A would have originally brought the LM&SS equipment to the OWS, but after the OWS’ mission planners became concerned that the first crew already had too much to do they decided not to go ahead with installing the LM&SS on the station. AAP-1A became a standalone mission more like the LM&SS’ original conception: a CSM and the LM&SS docked to one another to make a miniature space station of its own.

Whether attached to the OWS or the LM&SS, AAP-1A’s goal was Earth observation, but also to put the LM&SS through its paces for a nebulously planned Lunar observation mission that would get back on the schedule as a pure science mission sometime in the future. The basic problem this mission looked to address was interpreting the photographs of that hypothetical lunar mission. Observation missions during wartime had shown that it was actually quite hard to figure out what an aerial photo was trying to tell you if the enemy wasn’t about to let you look at what you were photographing with a later visit on the ground. With the Moon there was no enemy other than distance and cost, but establishing the “ground truth” was equally difficult. It was entirely possible that the LM&SS photos would be misinterpreted in critical ways because there was no way to cross-check those interpretations.

So somebody came up with the idea of launching the LM&SS on top of a Saturn IB. It couldn’t go to the Moon that way, but it could stay in Earth orbit and image parts of the United States that could be reached easily. Follow-up field trips on the ground would then go and look at what was imaged and learn how what was on film compared with the view on terra firma.

Somewhere along the way (and for reasons we’ll examine shortly) NASA decided not to use the full KH-7 module. Instead they commissioned Martin Marietta to develop a stripped-down version consisting of a small manned module with a small airlock to the film compartment; the astronaut using it would have to suit up, depressurize the LM&SS manned compartment, and then reach out through the lock into space to retrieve the reels. In return for the smaller size of the main camera arrangement, it was now possible to add a large suite of other sensors and cameras to the LM&SS as well as a few unrelated experiments. Martin Marietta designed an open tetrahedral truss made of aluminum, and wrapped it around the module to support the instruments. The module in turn was then docked to the CSM. While the truss-supported instruments were open to space and so generally intended to be self-sustaining, the LM&SS did have a second man-sized airlock so that an astronaut could go on a spacewalk to fix or retrieve one.

AAP-1A was planned out quite thoroughly and aimed to launch in either late 1968 or early 1969, just prior to Apollo 11 and as the Earth-orbiting mainstream CSM/LM tests Apollo 7 and 9 were underway.

What happened to make it fail: The Lunar Orbiter program was a roaring success: five out of five launches did what they were supposed to do, in contrast with the poor, benighted Rangers. The complementary Surveyor probes worked well too: seven landers and seven landings, though two did crash rather than coming down softly as designed. Apollo 12 even visited Surveyor 3 thirty-one months after it had proved its target to be a suitable landing site. Even so, as mentioned previously some NASA personnel thought that the Lunar Orbiter photos weren’t enough, and that something higher resolution would be needed. Nevertheless, the consensus emerged that what they’d got from the Orbiters was good enough, and that the LM&SS didn’t need to fly.

What may have tipped the balance that way was another pressure on the LM&SS mission. For many years it was believed that the LM&SS module was a modified LM, not a KH-7; only a little information about the program leaked out from industry insiders. Why? The KH-7 may have been obsolete (it was being replaced with the KH-8 just as NASA starting working on theirs), but it was still classified and it stayed classified until September 2011. While the NRO as a whole was willing to supply NASA with the equipment they needed, they  were nervous about even officially disclosing the existence of American spy satellites. If Apollo had absolutely needed it, they were would go along with putting one of their birds in the halogen-lamp glare of the Space Race in the hopes that no-one would look at it too closely and believe the cover story that it was a piece of NASA equipment.

So the first iteration LM&SS was cancelled because of the clandestine nature of the equipment they would have had to use. The radically less-open culture of the NRO that was supplying that equipment made it certain that it wouldn’t move forward once the primary goal of protecting the astronauts (or, more to the point, preventing American propaganda disaster) could reasonably have been said to be reached.

This is what morphed the LM&SS module into its new shape. Even though it was using the same camera, the module was heavily redesigned so as to make it less obvious where the camera came from. Even then the NRO was also apparently unhappy even to reveal that the US had the capability to image the Earth at high resolution, as would become obvious once AAP-1A’s photos were made available to the public; a document declassified in December 2011 named presidential science advisor Donald Hornig as the higher-up who pushed the issue. With their budget shrinking quickly NASA probably would have cancelled AAP-1A anyway, but certainly the concerns of the NRO were another straw on that particular camel’s back

What was necessary for it to succeed: Each of the variants of the LM&SS program failed for different reasons, so let’s take them in order.

For the initial one, using the KH7 to examine the Moon for Apollo sites, there’s the obvious possibility that Orbiters would have proven to be a second run of the Rangers. Alternatively, the faction of NASA that felt the images from the Orbiters still weren’t good enough and that the LM&SS module should fly might have come out on top. Having a rocket they could have used would have helped there. While the Saturn V wasn’t formally put aside until 1968, NASA had to have seen the writing on the wall, as they had been requesting funding for the sixteenth and seventeenth Saturns since 1966, and never could get it. If one or more of those had come through, the Lunar mapping program would have been right near the top of the list to be perched on one.

apollo-15-csm-camera-at-work

Apollo 15’s Endeavor with its scientific instrument bay open, photographing the Moon. Its camera was located at to the right of the white rectangle that can be seen near the centre of the bay. Public domain image from NASA.

The second proposal for lunar mapping, the scientifically oriented one that was to follow at an indeterminate point after the Earth Sciences test, fell by the wayside with the decision to do lunar mapping from CSMs of the regular Apollo missions. People often don’t realize that while two astronauts from each Apollo did their work down on the lunar surface, the third astronaut wasn’t idle while in orbit in the CSM above. Among the things he’d do while circling the Moon, at least during the J-class Apollo 15, 16, and 17, was photograph it using a 24-inch panoramic camera based on those used by the KH-7’s predecessors in the CORONA spy satellite program.

The difference that made flying one of those easier than an using an entire LM&SS was the nature of the camera. It wasn’t very hard to cover it up as a bespoke piece of equipment made for NASA, since in essence that was what it was, and its presence wasn’t as obvious because it was small enough that it could be stuck in the section of the Service Module (the SM being subdivided internally into six radial compartments) that was reserved for scientific equipment. Contrast that with the KH-7 module, which was obviously a piece of surveillance equipment, and one that massed 2000 kilograms and had to be docked to the front end of a CSM for the lack of anyplace else it would fit. There was no hiding that. The CORONA cameras may not have been as capable, but they were a lot more politically palatable. NASA’s willingness to take the CORONA cameras as “good enough” would have had to change before they would have pushed back against the NRO and tried for the full KH-7 LM&SS on this mission.

The Earth Sciences version of the LM&SS fell to several nibbling problems. By 1969 NASA’s budget was shrinking rapidly, so being able to shrink down to a cheaper Saturn IB was now not good enough—it was no longer even clear that the money to build the extra CSM and then support the mission would be there. On top of this the NRO continued to have concerns about what the capability of the LS&MM’s cameras would reveal to the world about their spy satellites, and weren’t keen to waste that secrecy on something as trivial as better maps of the world’s resources.

Next, by the time AAP-1A was planned to go in mid-1969, it had become clear that unmanned satellites were close to being able to map the Earth to the same level of fidelity (and in fact would start doing so with Landsat 1, which launched in 1972). And finally, even NASA had to accept that “testing Moon mapping systems” was putting the cart before the horse; it was far from obvious that they were going back to the Moon at all once the main line of Apollo missions had ended, as of course they haven’t in the years since. So what was the point of that? As there were so many things running against it, this is the version of LM&SS that was least likely to ever fly.

As a final aside it’s worth mentioned that NASA once again has their hands on some high-quality spy satellite cameras. In June 2012, the NRO donated two surplus telescopes to them, with media reports saying that their main mirrors were comparable in size to that of the Hubble Space Telescope. While it’s still unclear at the time of this writing what they’re going to do with them, NASA is believed to be considering plans to use them in a replacement for that aging orbital observatory sometime after 2020.

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