The latest issue of Space Safety Magazine is dedicated to it. I disagree with Andrea’s take here, though:
The focus of commercial space is very much on cost-cutting, while vague assurances are made about safer vehicles. Sometimes safety is even presented as a stubborn obstacle to industry development and progress [I plead guilty as charged - RS]. The commercial human spaceflight industry needs to remember that the primary goal of the Shuttle Program was cutting the cost of transportation to orbit by an order of magnitude, a goal at which it failed miserably. As with the supersonic Concorde, the Shuttle was doomed by being both expensive and unsafe. Being expensive made it in turn unaffordable to undertake any further development or safety modification. But even being expensive to operate did not stop either the Shuttle or Concorde from operating for about 30 years. What ultimately ended these programs was their inadequate safety.
Probably true for Concorde, but not for Shuttle. As I write in the book:
While many mistakenly thought that it had quadruple redundant computers because it was a manned vehicle, the presence of crew was irrelevant to the need for its reliability – it had to be reliable because they cost about two billion dollars each, and they only had four of them at most operational, sometimes only three, at any given time, with production lines for components shut down in the eighties. The fact that it wasn’t reliable to “n” nines (where “n” was at least three, or would fail less than one in a thousand times) meant that the program was in fact a failure. Ultimately, this was why it was canceled, not because it killed fourteen astronauts who are, in comparison to just four Shuttle orbiters, and at the ever-present risk of sounding cold hearted, if not a dime a dozen, certainly available in surplus numbers.
After Challenger, the crew didn’t need a fire-pole escape system, or ejectable crew capsule, or any of the other impractical changes that some wanted to make to improve the Shuttle’s safety, any more than airline passengers need parachutes – they needed a more reliable vehicle. And there was no way in the end to provide it with the Shuttle, because its reliability was too compromised by its intrinsic design resulting from its pinch-penny development. That’s why the program failed and was canceled, not because it was unsafe per se. We simply couldn’t afford to continue to lose orbiters.
The corollary to this is that any reusable vehicle that is sufficiently reliable to make economic sense is sufficiently reliable to carry valuable cargo, including humans, simply because the vehicle itself is so expensive, and there is nothing about space vehicles that changes this intrinsic economic argument. Note that this is almost completely independent of what we think a human life is worth (unless we believe that the value is infinite, which many behave as though they do). This is why “human rating” (the modern PC version of “man rating”) is an archaic relic of early and unreliable expendable vehicles, and is a phrase that should be banished from the policy and engineering lexicon.
If what they were doing in space had been important, a one-in-a-hundred chance of loss of crew might be just fine, particularly if we had a large enough fleet. As I note in the book, a four percent loss of aircrew per mission in WW II was considered acceptable by the Army Air Force. The real problem with government spaceflight is that it isn’t important. And for private and commercial spaceflight, both service providers and customer are going to have to make their own assessments of what is an acceptable risk. It’s none of the government’s damned business. I’d also note that commercial industry’s assurances of safety are no more “vague” than NASA’s have ever been.
By the way, Andrea is supposed to be reviewing my book. I’ll be interested to see what he says.
One other important difference between Concorde and the Shuttle. One was an airliner, with a high expectation of passenger safety. The other…wasn’t. Or at least shouldn’t have had such an expectation, particularly after Challenger.