Category Archives: Space

It Ain’t Heavy, It’s My Lifter

Jon Berndt has an article in the current issue of the Houston AIAA newsletter on the subject of heavy lift, citing yours truly, among others. (Warning, it’s a three meg PDF). My only quibble is that he misses one of the other problems with a heavy lifter–lack of resiliency. If we develop an exploration architecture that’s dependent on heavy lift, then we should have multiple means of providing it, which means two development programs with inadequate flight rate to amortize the costs.

Along similar lines, Bob Zubrin has a long essay on space policy in The New Atlantis that’s now available on line, with a harsh critique of NASA, including the Bush-era NASA and Sean O’Keefe. Surprisingly, I agree with much of the early part of it (though as always, the tone is a little problematic). I don’t agree with this:

The ESMD plan requires a plethora of additional recurring costs and mission risks for the sole purpose of avoiding the development cost of a big new rocket

A Million Here, A Million There

A commenter at this post writes:

When it costs hundreds of millions of dollars to fly a single Shuttle mission, I fail to see the problem with spending another 10 to fix the wiring.

The first problem is a misunderstanding of Shuttle costs. The marginal cost of a flight is not “hundreds of millions of dollars.” It’s probably somewhere between a hundred and a hundred and fifty million. The average cost is much more, but that’s not a useful number, because it can vary so much with flight rate (for example, when the flight rate is zero, as it has been since February, 2003, the average cost per flight is infinite, regardless of how much we spend on the Shuttle program).

The second problem is that, while ten million dollars may not seem like much in the context of a program that costs billions annually, the fact remains that NASA has a finite budget, and ten million spent on one item is ten million less available to be spent on something else, that might be more important. According to the article that the original post linked to, the odds of an uncommanded thruster firing resulting in a catastrophe are somewhere between one in ten thousand and one in a million (it doesn’t say if that’s on a per-mission basis, or totaled over the next twenty-odd flights). Assuming that those are valid numbers, with any degree of confidence, then the standard way to determine how much we should spend to prevent that event from happening would be to use the expected value of that event (probability times cost). The problem with that, of course, is assessing the value of either the Shuttle fleet, or the ISS, given that current policy recognizes them both as dead ends, in terms of future space policy.

That, in fact, is why I think that the CAIB recommendations should have been revisited after the new policy was announced. If the CAIB had known that the Shuttle was going to be retired at the end of the decade, they may not have recommended some of the more costly (and impractical) fixes for what would then have been recognized as a rapidly depreciating asset.

Past Its Sell-By Date

This article, describing the potential danger of an uncommanded thruster firing, is just one more illustration of why the Shuttle has to be retired, and the sooner the better.

Back in the olden days, when I worked at Rockwell in the eighties and early nineties, some of my colleagues would write technical papers, in all seriousness, that we would likely be flying the Shuttle well into the 2020s or 2030s. Ignoring the fact that this was a self-serving delusion (we were, after all, in the business of building and flying the things), their logic was that it was designed for a hundred flights, and at the low flight rate we were getting out of it, it would easily last well into those decades. I didn’t make myself very popular when I laughed at this logic, but I did nonetheless.

Setting aside the issue of what a disaster it would be for space policy if we were still flying such an economically absurd system five decades after it had been designed, they didn’t seem to understand that, like the old oil commercial, “think months, not miles.” The fleet is aging, as we saw a couple years ago with the cracks in the fuel-cell liners. The standard rejoinder to this argument is that we are still flying B-52s that were originally built in the 1950s, and in some cases we have grandsons of some of the original flight crews flying them today.

That ignores the economics, of course. B-52s are heavily used, still flying sorties every day, and it makes sense to continue to maintain and inspect them, because the cost of doing so is amortized over a large number of flights. But it’s hard to justify the expenditure of many millions of dollars to replace wiring in the RCS, when the fleet is going to be retired soon anyway, and only flies a few times a year. This logic applies to almost any maintenance/replacement issue with the vehicles, all of which are uniformly hyperexpensive to implement. Unless it’s a clear and obvious safety issue in the context of the next couple dozen flights, it’s very hard to justify the expense at this point.

Into The Mainstream

You know that space tourism is being taken seriously when you can read about it in Travel and Leisure magazine. This piece by Los Angeles writer M. G. Lord was in the January issue, which Patricia just pointed out to me.

I last saw M. G. last June in Mojave for the first SpaceShipOne flight into space. I hadn’t realized that she has a new book out. It looks quite interesting. Check out the review by NASA historian Roger Launius.

The Myth Of The Right Stuff

Jeff Foust has an article today on a recent speech by Gene Kranz (yesterday was the thirty-fifth anniversary of the successful return of the crippled Apollo XIII). It’s become popular myth as a result of Ron Howard’s movie that Gene was the director of flight control, solely responsible for getting the crew back safely, when in fact there were more than one. In my opinion, Glynn Lunney in particular gets short (in fact zero) shrift in the movie, though the work obviously had to be done in shifts.

But I’m afraid that we (and I include Gene in this) take the wrong lessons from that incident. Yes, the teamwork was splendid, and the improvisation excellent, and they did everything they needed to do to get them back. But as I commented back in days immediately following the loss of Columbia, those are necessary, but not sufficient, to ensure that we won’t lose people in space. It has to be recognized that in addition to all of the smart moves on the ground, that crew was also damn lucky. If that explosion had happened while the crew was on the surface, or on the way back from the Moon, they’d have died, no matter how much derring do was on display in Houston. A lot of other things could have gone wrong that would have killed them, and no amount of teamwork, training, and smarts would have prevented it.

Sending people into space is a risky business, and we have to accept that. It sounds nice when Gene says it, but “failure is not an option” isn’t a realistic attitude. As someone once said, when failure isn’t an option, success gets damned expensive. And of course, the easiest way to ensure that failure isn’t an option is to not even make the attempt.

Reducing The Cost Of Access

My current partner in crime here, Sam Dinkin, has some interesting ideas about how to encourage space activity and drive down costs over at The Space Review today. I don’t agree with all of them, and I’m sure that in some cases there may be some bad unintended consequences, though I haven’t given them enough thought to identify any yet.

I like the idea of subsidizing EELV at the margin. Government policy in general doesn’t seem to understand the concept of marginal cost (one of the reasons that both Shuttle and ISS are programmatic disasters), and a more explicit recognition of its importance could have some good policy outcomes.

I’m not sure what he means by “privatizing ISS and Shuttle,” I think that the infrastructure to maintain both of them is too expensive for anyone to operate at a profit, even if they were given away.

Eternal Sunshine Of The…

…well, not the spotless mind, but actually the lunar north pole.

This is very interesting, for two reasons. Most plans for lunar bases assume a need for a nuclear power plant, because of the two-week-long night there. Discovering regions where the sun always shines means that we can get by with solar power. From a design standpoint, it will also be a lot easier to design equipment for a single temperature (-50 C) than for an environment with huge temperature swings, which is the case between lunar day and night.

The real question now is whether or not there’s ice in the craters, where the sun never shines, as seems to be the case at the south pole.