Charlie's Diary: Back to the Moon?: I was thinking I ought to be looking for something creative to say here — blogging gets old, after the first eight years — when a bright young thing at $PUBLISHING_COMPANY emailed me to say: "on the 20th, it's going to be the 40th anniversary of moon landing day, wanna blog about where you were and what it means to you on our corporate soapbox?"
To which I said "sure, but I was only four years old at the time ..."
I hope to live long enough to be four years old that way all over again, some day.
Why didn't Apollo stick?
Well, for one thing, it was a stunt.
Wernher von Braun and his colleagues didn't see it as a stunt, of course. They saw it as a stepping-stone, a valuable intermediate step in establishing a metaphorical beachhead in space. And rightly so (given the state of knowledge of how biological organisms handle zero gravity and high radiation environments at that time).
Unfortunately, the real goal of the rocketry pioneers called for something a bit bigger than an ICBM. Funding their requirements ... not easy. The price of a launch to orbit scales roughly in proportion to the cube of the payload. A modern, miniaturized H-bomb weighs about 200-400Kg (more for the really big stuff, but they're not terribly effective militarily). An ICBM that can lob 3 warheads around the world is actually only lifting about one ton of payload, and it doesn't even reach orbital velocity: it's around the bottom end of a viable space launcher. Von Braun and his Soviet counterparts like Sergein Korolyov knew this well. Korolyov had the relative luxury of the USSR's plutonium shortage and lack of proficiency in guidance technology to help him justify building big rockets: these factors forced the Soviet ballistic missile forces to use single multi-megaton H-bombs (weighing several tons), which in turn needed a 300 ton monster like the R-7 Semyorka to achieve their military goals. The R-7 was big enough to throw a small satellite into orbit without upgrades; with incremental improvements, it has continued to evolve (long after its military obsolescence) into the R-7 family of space launchers, one of the safest and most reliable multi-stage liquid fuel rockets ever.
But the United States had much better guidance technology, and more plutonium (and could therefore use numerous small, efficient, accurately-targeted warheads to do the job for which the Soviets had to rely on a few cumbersome city-busters). While the early US ICBMs were reconfigurable as space launchers, the really big job of going to the moon required something new — the Saturn series of boosters. And the Saturn V configurations that eventually flew to the moon and launched Skylab were far from the largest variants planned.
Let me put it this way: the goal of going to the moon by 1970 forced design compromises on NASA. The objective of putting a man on the moon and bringing him back would be achieved using the lightest lunar lander conceivable — one so flimsily built that, on one occasion, an engineer working in the cabin of one of the LEMs dropped a screwdriver point-down and it punched right through the spacecraft's skin. The LEM weighed under 15 tons, fully fuelled; the ascent stage, in which the crew were to live until they returned to dock with the command module, weighed barely 2000 kilograms (plus crew and 2350Kg of fuel).
Not only does the cost of putting a payload into orbit increase with the cube of the payload weight — this rule holds true in the opposite direction, too. Stick a LEM on the moon and bring the contents back? Easy. Increase the mass that the LEM brings back? Very expensive — the price goes up as the sixth power of the weight you're returning from the lunar surface (because you have to loft the heavier LEM into Earth orbit to begin with).
Think about it. The real mission wasn't to go to the moon; it was to bring two astronauts and 100Kg of moon rocks back from the lunar surface and into lunar orbit (to rendezvous with the CSM stack for the journey home) — and it took a 3000 ton behemoth to accomplish this. Launching a bigger, more useful LEM (one that could carry 3 or 4 astronauts to the lunar surface, along with a decent-sized rover and supplies for a couple of weeks) would have added tonnes to the LEM payload ... and hundreds, if not thousands of tons to the launch stack. With cost scaling as the cube of the vehicle mass, you don't need to be an accountant to realize that the US government, stuck fighting a war in South East Asia, wasn't going to give NASA the money to build in even one kilogram more of payload than was strictly necessary. Indeed, the mushrooming weight of the LEM (it gained about 15-20% during development) threatened to jeopardize the whole mission profile — except that the Saturn V performance exceeded expectations. The per-launch cost of even a minimal Apollo moon shot was $431M, in 1967 dollars — call that $5-10Bn today.
So: the original Apollo moon shots couldn't have easily scaled up to achieve more — not without throwing a lot more money at the program in 1968-70, at a point when NASA was already consuming 0.5% of US GDP. For comparison, NASA's budget in FY 2008 was $17.3Bn; if NASA was funded at 1967 levels today, its budget would be closer to $75Bn.
Is NASA capable of going back to the moon?
I want to believe. But ...
First the argument in favour. The Soviet manned lunar program (cancelled in 1969) were running on less than a tenth of NASA's budget; they nevertheless got four flights into the test program for the N1 before it was cancelled, and may have been on the edge of solving its engine problems. Today, with better simulation and modelling techniques, new materials science, and much better electronics — not to mention 30 years more experience in space exploration — we ought to be able to design and build better (and importantly, cheaper) spacecraft.
Moreover, on the basis of the current estimates, a lunar round trip in Orion/Altair will represent a huge bargain compared to Apollo — delivering 60% of the lunar astronaut surface duration of the entire Apollo program, for a tenth to a fifth the price of a single 1960s moon shot. Even if it undergoes a 100% cost overrun, it'd be cheap compared to Apollo.
But there are problems. Today we lack a vital resource that both Wernher von Braun and Sergei Korolev took for granted: thousands of engineers with the experience of designing, building, and launching new types of rocket in a matter of years or even months. We used to have them, but some time in the past 40 years they all retired. We've got the institutions and the data and the better technology, but we don't have the experience those early pioneers had. And I'm betting that the process of rebuilding all that institutional competence is going to run over budget. While NASA's Constellation program might work, and while it could deliver far more valuable lunar science than Apollo ever did, it will inevitably cost much more than NASA's official estimates suggest, because it's too big a project for today's NASA — NASA, and indeed the entire space industrial sector in the USA, would have to grow, structurally, to make it work.
Constellation won't survive a 100% cost overrun — or even a 25% one. Instead, it will almost certainly be cancelled. The fiscal realities of the second decade of the 21st century are horrendously worse than those of the sixth decade of the 20th. The sixties were a boom decade; a better comparison would be the stagflation era of the seventies (never mind the Great Depression). The Shuttle program survived the 1970s but only just — its budget scraped through by a single senate vote at one point. And the Shuttle's specifications were mutilated by the political need for it to support an Air Force mission (one that it never flew, but which nevertheless ultimately doomed the Columbia). Project Constellation has no such USAF mission to cling on to for dear life when the budget axe is swinging.
And so I very much fear that I'm going to have to stay fit and aim to live for a very long time if I want to feel four years old all over again.