Was the Apollo Programme the best option for long term space exploration?

Question

Let us take the following as axiomatic:

1. The long-term future of humanity is dependent upon the successful colonisation of space,
2. The Apollo Programme was the greatest technological achievement in history.

The Cold War-motivated programme to land humans on the moon, and return them safely to Earth was clearly successful by the standards of its objectives but, given the technological development of the time, there was no way to easily turn the success of those missions into a long-term lunar presence for humans. Instead, for the next few decades, space technology concentrated on satellites, deep space probes, and low-Earth orbit habitation.

It is now nearly 50 years(!) since a human last set foot on the moon. Given the enormous resources dedicated to Apollo, would we now have a more advanced presence in space - perhaps a permanent lunar base - if those resources had been provided to other space technology instead?

In answering this question, I would be particularly interested in documented plans published before the Apollo Programme was started describing alternative, long-term, space exploration strategies.

Answer 1

To offer a direct answer up-front, this document published by NASA's chief historian in 2000 examines NASA's missions and history from 1950-2000. I admittedly have only skimmed this document, but this is probably one of the best documents you'll get showing NASA's pre-Apollo plans. An important factor to consider with your question of "what if NASA focused on something else back then" is the historical context - the US and USSR were basically trying to prove to each other that they could nuke each other more than the other party. So the Apollo program wasn't predicated on "let's eventually get to Mars", but moreso on "how well can we master rockets for the purposes that we need them today?", meaning that the program itself wasn't built with sustainability or long-term technology development (relating to deep-space exploration anyway) in mind. Now, putting the historical context aside for a bit, let's talk about why it wasn't sustainable.

The Apollo Program is considered a "flags and footprints" program in which the goal was basically to go to the moon for the point of saying that it could be done. Generally speaking, this type of program is not sustainable for long-term exploration because once you have achieved your objective, there is little incentive to continue sending more missions. While the later Apollo missions had expanded science objectives compared to the first, the financial cost and human risk of each mission quickly outpaced the marginal science and prestige returns. After the first few missions, NASA already had enough lunar samples to a great deal of analysis. Getting more samples would be nice, but they wouldn't give much more information than what was already had by the first samples. Also, saying "I can go to the moon and come back" is extremely impressive. Being able to do it twice proves it wasn't just a fluke. Doing it a 7th time instead of a 6th time just isn't as big a deal. Considering the relatively huge amount of the US budget that was going towards NASA at that time, Congress eventually decided that the point had been made and there was no need to do more missions.

Just because Congress pulled the plug on the program doesn't mean that an incredible amount of technological progress was made in many fields: some examples and more examples. The problem wasn't that the program wasn't productive, it was that there wasn't a reason to continue doing it once the single, clearly defined objective was achieved. So what kind of program would be more successful in the long run?

Three major factors to consider are the goal(s) of the program, the technologies available to achieve the goals, and the funding available to support technology development and mission operations (plus everything else required to make those happen). First, NASA would need to develop an appropriate goal. The goal itself would need to be indefinite, or at least provide concrete progress towards a more advanced goal. These could be something like: long-term LEO/cislunar colony, human asteroid landing, permanent lunar colony, permanent Mars (or Martian moon) colony, or something similar. Now, if NASA can create an efficient technology roadmap to achieve this goal AND it can create a plan to effectively develop the required technologies within a reasonable annual budget, then the program could have a shot at surviving for a long time.

A series of comprehensive studies by NASA that looked at the long term exploration of Mars are the Mars Design Reference Missions. The first one was completed in 1993, and the most recent one was completed in 2009. Each iteration took into account lessons learned from previous versions of the study, as well as new and changing technologies. Another solid study done by JPL in 2015 was the Minimal Mars Architecture (I couldn't find a public version of their paper). There have been many other studies of varying magnitude by other authors, but the examples I gave are from some of the biggest brains in NASA.

Answer 2

Following on from @PaulW's answer above, the document archive that he references also contains the following 1962 paper describing the steps require to build a permanent human base on the Moon by the mid 1970's in which the Saturn C-5/Saturn V was a practical option for delivering the necessary base hardware.

Given this information, it is reasonable to conclude that Apollo did fulfil the technical requirements for sustainable exploration, and the cancellation of the programme was due to political and economic reasons rather than technical difficulties.

Answer 3

In short, no. @PaulW's answer provides some interesting context, but keep in mind the goal that Kennedy set for NASA: to put a man on the Moon and bring him back before the end of the decade. The Apollo Program started already in 1960, started by Eisenhower before Kennedy was even president. At that time there was no specific goal, although a lunar landing was definitely part of the scope.

Then in 1961 Kennedy publicly announced the goal to put a man on the Moon before the end of the decade. In order to achieve this, the design philosophy revolved very much around how to achieve this goal with as little technological advances as possible:

To accomplish the moon landing within the time set by President Kennedy. Apollo's designers deliberately hewed to techniques that did not reach far beyond the state-of-the-art in the early Sixties.

(source)

The rationale being of course that the bigger the technological leap, the bigger the risk to the timeline.

The corollary of this approach was of course that the Apollo-Saturn vehicle provided the bare minimum in order to reach the goal with hardly any margin (the addition of the rovers in the last few missions was made possible by squeezing a bit more performance out of the Saturn V beyond the original design parameters). A lot of money was spent on just that, without very little (if any) regard for the milestones and developments beyond. Skylab was an interesting epilogue, but a bit of an afterthought with a repurposed S-IVB stage. The fact that the remaining Saturn stages were not even used (some on display even), illustrates that the Saturn V vehicle had fulfilled its purpose. The Saturn-Apollo program was not a sustainable technology path.

When you look at historical sources describing plans Launch Complex 39, Moon bases, space stations etc., you'll find that they are mostly either from the late 50s, early 60s, or from after 1969 in an attempt to keep the program going. In the time frame in between all focus was on that singular goal of the Moon landing before 1970. It is possible, maybe even likely, that had Kennedy not been assassinated, the Saturn-Apollo program would have evolved at a more relaxed pace, with less peak spending and thus less resistance from the Senate, allowing for more steady and robust technological developments and different milestones, but I guess we'll never know.

Answer 4

Well, no. Way too expensive. What SpaceX is doing now is probably the best option but ...

The long slender Saturn 5 had major issues with harmonic oscillation under its massive thrust. This is one of the reasons why the shorter, chunkier Space Shuttle design followed on.

The Space Shuttle design was hamstrung by the need to recover the main engines, which resulted in a gigantic orbiter with limited cargo dimensions.

These days, we can recover boosters, which frees up orbiters to a far more sensible configuration of separate shuttle (second stage) and extremely flexible (you name it) third stage/cargo/manned shuttle design.

Ironically, the Saturn 5 second stage could have been a winged shuttle with only minor modifications. But SpaceX may have some hard lessons to learn about long, slender rocket designs.

The mighty Saturns were a tremendous technological achievement in their time, but are being superseded by today's technology.