One of the reasons that NASA is willing to launch the Shuttle, even though they can’t fully resolve the foam issues, is that they’re not concerned about losing a crew from it, as they did with Columbia, because they’re going to ISS, and can remain on orbit if necessary, at least for a while. I should note that I may have been the first to publicly discuss this option, less than a week after Columbia was lost, in which I advocated that we tame the wilderness into which we had sent the crew of that ill-fated ship:
I’ve written before about the fragility and brittleness of our space transportation infrastructure. I was referring to the systems that get us into space, and the ground systems that support them.
But we have an even bigger problem, that was highlighted by the loss of the Columbia on Saturday. Our orbital infrastructure isn’t just fragile–it’s essentially nonexistent, with the exception of a single space station at a high inclination, which was utterly unreachable by the Columbia on that mission.
Imagine the options that Mission Control and the crew would have had if they’d known they had a problem, and there was an emergency rescue hut (or even a Motel 6 for space tourists) in their orbit, with supplies to buy time until a rescue mission could be deployed. Or if we had a responsive launch system that could have gotten cargo up to them quickly.
As it was, even if they’d known that the ship couldn’t safely enter, there was nothing they could do. And in fact, the knowledge that there were no solutions may have subtly influenced their assessment that there wasn’t a problem.
The lesson we must take from the most recent shuttle disaster is that we can no longer rely on a single vehicle for our access to the new frontier, and that we must start to build the needed orbital infrastructure in low earth orbit, and farther out, to the moon, so that, in the words of the late Congressman George Brown, “greater metropolitan earth” is no longer a wilderness in which a technical failure means death or destruction.
NASA’s problem hasn’t been too much vision, even for near-earth activities, but much too little. But it’s a job not just for NASA–to create that infrastructure, we will have to set new policies in place that harness private enterprise, just as we did with the railroads in the 19th Century. That is the policy challenge that will come out of the latest setback–to begin to tame the harsh wilderness only two hundred miles above our heads.
Note that in its proposed ESAS architecture, NASA has not learned those lessons, though COTS may be a baby step in that direction, if it survives.
In any event, I wonder if they’ve really thought the scenario through?
OK, they launch, and the cameras reveal that they’ve taken some foam hits on the way up. They get to ISS, and do an inspection. There are three possibilities:
- The damage is obvious, and will obviously be fatal if a return attempt is made
- The damage is minimal, and it’s obvious that a return is safe, or
- The damage is obvious, but less obvious is how dangerous a return attempt would be.
Scenario 2 is easy–just come home.
Scenarios 1 and 3 are more problematic. Scenario 1 is actually two potentials–one in which there is no hope of repair, and the other in which a repair attempt can be made, which converts it to scenario 3, since the degree of confidence in an in-space repair will be unknown, given our lack of real-life experience with it.
But for Scenario 1 in which no repair seems possible, the orbiter is now the largest piece of space junk ever launched. What do we do with it?
Well, if we had ever installed the servos necessary to drop the gear and control the nose wheel and brakes, we could send it down sans crew with fingers crossed, and hope that we could recover it regardless of the damage. There would, after all, be nothing to lose. Presumably this would be an Edwards landing, so the breakup, if/when it occurred, would happen safely over the Pacific (no need for recovery of the pieces, since there will be no doubt of what caused the vehicle to break up).
But wishes aren’t horses, and the vehicle is in fact not capable of landing without someone in the cockpit (a state in which it has remained for years as a result of pressure from the astronaut office, or so rumor has it, out of a fear of redundancy). So any return of the crippled orbiter has to be a planned crash landing, should it beat the odds and survive the entry.
So, do we just drop it in the ocean, or do we attempt to belly it in (again, at Edwards). The former is the safest option from the standpoint of third-party hazard, but if we could get it down in (sort of) one piece, then we might learn more about how the damage to the tile seen on orbit correlated to damage that occurred during entry, which would be useful for future TPS design work. We would also have a source for cannibalization of parts should Mike Griffin change his mind and decide to finish out ISS with only two vehicles remaining.
So, those are the options where we are reasonably sure that we have a doomed vehicle. Not easy decisions, but neither are they ones that will keep a NASA administrator up at night.
The really ugly choices come in with the scenario in which the prospects for a safe entry are uncertain.
We still have a three orbiter fleet. It would be highly desirable to keep it at that level. Depending on the perceived level of damage, do we get a volunteer to attempt to bring home a very valuable national asset (one is enough, I believe)? There’s a limited pool, of course–it has to be one of the crew at the station, and only a small subset of that crew is qualified for the job. If someone does volunteer, does the agency accept it? It would be irrational to throw away a third of the fleet, and a multibillion dollar asset to avoid risking the life of a willing volunteer whose job it is to take such risks, but I can imagine the agency doing exactly that (with no doubt a lot of kibitzing from the peanut gallery on the Hill).
That’s the kind of decision that causes sleepless nights for flight directors and agency heads.
Note that in none of this discussion have I yet addressed how to ultimately get the crew down, and to support them at a crowded ISS until such a time as we can do that. Options for crew return are multiple Soyuz flights, or simply chance another Shuttle flight, with the risk of stranding yet another crew, but only a two-person crew this time. The chances of two incidents in a row (and three out of four in a row, counting Columbia–though that makes it a conditional probability) seem pretty slim to me, but of course the probability of heads on a coin toss is always fifty fifty, regardless of the history. If this option is chosen, likely this will be the last Shuttle mission ever flown, regardless of its success. Unless we become more rational about such things, in which case we may do one more to repair Hubble.
In any event, the administrator may have set himself up for some very interesting decisions in the near future with his decision to launch.
[Update late afternoon Pacific]
I see over at The Flame Trench that NASA plans an August 21st rescue mission with Atlantis (a week earlier than its planned August 28th mission) should it be necessary. That means a seven-week stay at ISS.