The Lunar Surface Access Module can do far more than even what NASA contemplated for the follow-on missions to Apollo. (credit: NASA/John Frassanito and Associates)

Just another Apollo? Part two

by Daniel Handlin
Monday, November 28, 2005

In mid-1969, as the Apollo missions were reaching their climax, NASA managers began to plan for the next phase of lunar exploration. This optimistic plan, issued by the Space Task Group, would have had NASA’s funding stay at Apollo levels, and, in a series of steps that followed Apollo, would have seen NASA develop such elements as a lunar orbit station in 1978, a lunar surface base in 1980, and a manned mission to Mars in 1981 or 1983. President Nixon rejected the ambitious Space Task Group plan, choosing instead to develop the infamous, loved and hated space shuttle.

Since the ultimate goal of the new ESAS program as far as the Moon is concerned is to develop a lunar outpost, and since this article is comparing the ESAS to Apollo, it would behoove us to examine the plans that existed under the STG plan and the Apollo program itself to begin a follow-on to Apollo, for the purpose of comparing them to what is now being conceptualized for the ESAS.

Hey taxi!

Right after the first Apollo landings, NASA planned to use modified Lunar Modules (LMs) to begin setting up small lunar outposts around 1971 or 1973, after Apollo 20, the last planned mission of the program. This was part of the Apollo Applications Program, of which Skylab was the only real part that survived the budget cuts. In this idea, multiple Saturn 5s would have been launched to the Moon. Some of these would land unmanned “LM shelters” on the Moon, which would have deleted the ascent stage and would have carried more consumables and science equipment, better vehicles, living space for the crews, power, communications, life support, and so forth.

A manned Command and Service Module (CSM) would have accompanied the LM shelter to the Moon to brake the shelter into lunar orbit, but would only have performed science from orbit as the shelter did not have an ascent stage. LM “taxis”, launched separately, would then arrive on the Moon, carrying crews of three. The “taxis” would rendezvous on the surface with the LM shelters. The crew of three could stay on the Moon for about a month in the initial stages (this was limited by the duration of the Apollo CSM that would return the crew to Earth). Another LM “truck” vehicle would provide logistics support by removing the upper stage and replacing it with cargo. Eventually, several LM shelters, LM trucks, and LM taxi descent stages could be linked together to provide ever-growing levels of capability. A single Saturn 5 would launch a LM truck with a CSM, or two LM trucks with an SM for lunar orbit insertion. Later, even larger shelters (though not directly derived from a modified LM), called LESA (Lunar Exploration System for Apollo), would land on the Moon, providing quarters for six astronauts for up to 18 months at a time, and including a pressurized rover called “Molab” (Mobile Lunar Laboratory).

By building on Apollo technology, surface stays would gradually be extended from three astronauts with Apollo-like capabilities for a month to a base of six people with a pressurized rover and yearlong stays on the Moon. This plan was logical and followed directly on from existing technology, adapting existing LMs and creating from the LM three separate lunar-landing spacecraft capable of supporting long-duration surface stays. The only reason it was not done is because politically it was inexpedient for the Nixon administration to continue supporting the Apollo program, which it saw a legacy of the Kennedy and Johnson administrations.

The self-contained lunar outpost

As described in Part 1 of this article, even the baseline LSAM could support four crew for six months on the lunar surface, exceeding the capabilities of even moderately well-developed Apollo-derived outposts of the LM taxi/shelter design. The LSAM in its cargo mode can carry 21 tons to the lunar surface; even the dedicated LM truck could only carry about five tons of cargo to the surface. In its most rudimentary mode, as envisioned for the first ESAS missions, the LSAM can fill the role of the LM taxi (by providing transport to and from the lunar surface), the LM truck (by carrying half of the five tons of the LM truck payload), and the LM shelter (by providing science equipment and living quarters for a long duration). This single LSAM would not only fill the role of all these separate Apollo spacecraft, but would carry more crew than would the LM taxi/shelter/truck concept (four instead of three), and for six months instead of one. The LSAM is truly a self-contained lunar outpost. If additional LSAMs were used to carry cargo to the surface, they could each carry the cargo of four separate LM trucks (two or four Saturn 5 launches!). The question of economy as compared to the Apollo lunar outpost plan clearly favors the ESAS. Once again, we see that the ESAS is not a rerun of Apollo!

And that’s only the beginning. Just like Apollo, current ESAS ideas envision linking several LSAMs together on the Moon. Some would provide power, while others might carry consumables and communications. By linking many LSAMs together, a lunar base of formidable capability could be built up in a very short time. Even the complete LESA, including a Molab, would have had a mass of only half of what the cargo LSAM could carry to the surface. Just a few LSAMs could provide more capability than an advanced LESA base would have under Apollo. If the LSAM were launched as frequently as the LMs would have been under the Apollo Applications Program, a very large lunar base could be established very quickly. Obviously the delivery of enormous pressurized exploration vehicles and crew habitats presents no problem whatsoever in terms of delivery to the lunar surface, because of the LSAM’s staggering cargo capacity.

The new base

One of the lines of criticism against the ESAS is that programmatically it is too similar to the crash Apollo program. Whether the ESAS is a “crash program” (over 13 years?) and whether it is a bad thing to have a crash program will not be discussed here. However, it is evident from our examination of its capabilities that in the short and medium term, the LSAM will allow the establishment of a lunar outpost of significantly greater capability than lunar outposts of the Apollo design discussed above. A lone LSAM could be equivalent to a small Apollo outpost, filling the role of truck, shelter, and taxi, as described above; an LSAM supplemented by a second cargo LSAM would have the capabilities of an Apollo-type outpost of a fairly large size, with several LM trucks having landed. Once additional LSAMs start landing with dedicated power, communications, science, and habitat equipment, the new lunar base will have capabilities far beyond anything envisioned even with the long-term LESA system. Additionally, the long-duration capability of the basic Block 2 CEV will provide easier assured return capabilities than would have been possible with even extensively upgraded Apollo CSMs. Even the very first CEVs will have a longer duration than the advanced long-duration Apollos being studied for support of the Apollo Applications base.

In the long term, just as the LMs were to be replaced with the new LESA vehicle, the LSAMs could be replaced by something even larger. The characterization of the ESAS as a crash program is not a good one. The ESAS will allow the construction of large lunar outposts very soon after its inception. Considering that the LESA, which could have provided crew quarters for six for up to 18 months (supplemented by logistics flights), had a total mass less than half of what the cargo LSAM can deliver, it is plainly evident that a very large lunar base can be supported by ESAS. The crew size of the new lunar base may be limited by the rate at which crews can be rotated into and out of the base rather than by base capacity. Within ten years of the construction of the lunar base, even without a larger vehicle than the LSAM and its cargo version, the base should be able to evolve into a sophisticated Antarctica-like research station, with small crews of perhaps 10–15 astronauts manning the station for 6–12 months at a time, mining their own oxygen and water (well, maybe), and conducting experiments in lunar geology and astronomy. This will provide experience for operating Mars outposts, and the use of methane engines allows hardware testing for the Mars missions to be done on the Moon as well.

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