More SpaceX Reusability

For years, it was understood that NASA wanted new Dragons for its CRS missions. But today SpaceX is going to fly a used one, with the agency’s permission.

As I’ve long said, there will come a point at which a launch customer will say, “Wait, you want me to trust my ass or my payload to an unflown vehicle?” We’ll look back in amazement at the first seven decades of spaceflight, when we thought it made perfect sense to put payloads on untested systems, and then throw them away after a single flight.

[Update a few minutes later]

Note that NASA allowed this for a cargo mission. I’ll bet they’ll still want new capsules for crew for a while. Speaking of which, NASA is admitting that Boeing and SpaceX are going to have a hard time meeting the totally arbitrary LOC goal of one in 270. I love this:

“The number one safety-related concern for the program is the current situation with respect to the estimate of loss of crew,” Donald McErlean, a former engineering fellow at L-3 Communications and a member of the panel, said at the meeting. “The threshold values were considered to be challenging, and both contractors currently have a challenge to meet that precise number.”

Got that? They’re going to have difficulty meeting that “precise” number. As I noted in the book, the precision with which they calculate these utterly arbitrary numbers, given the state of knowledge about the system, is absurd. And this is the sort of thing that keeps us dependent on the Russians, when neither we nor they have any idea what their reliability or LOC number is.

20 thoughts on “More SpaceX Reusability”

  1. The LOC numbers are close to meaningless. Not worth the paper they are printed on. NASA – if anyone – should realize how badly they estimate reliability of systems, but I guess they are doubling down and pressing on.

  2. The flight is tomorrow (June 1). IIRC it was originally scheduled for today, but at some point the date was changed.

  3. From what I’ve heard so far of both capsules there is nothing which makes me think they would be less reliable than the Soyuz. So what’s the issue, really?

      1. In that case I think the best you could do is force astronauts to wear suits while in transit to prevent fatalities in depressurization events. Plus ensure that either the heat shield is robust enough to handle impacts or that it can be easily inspected and fixed in orbit. That might be hard to achieve though considering the characteristics of most refractory materials.
        Anyway it makes no sense to delay any further if it’s good enough to replace the Soyuz then worry about that for the next commercial crew contract or whatever.

          1. Along the lines of Godzilla’s spall liner suggestion, they could throw an easily removable kevlar cover on the capsule while its waiting to be used. Worst case scenario, they just leave with it still on. If it is easy to put on and take off, they just need a couple up there to put on lifeboats as they cycle through.

          2. Interesting; hadn’t seen that. I would have assumed it was sitting there with the hatch closed; even if it is holed you lose the lifeboat, not crew (barring a second unlucky incident). Am I missing something?

      2. Oh right I remembered another thing that could be used, if it isn’t already, a spall liner made of Kevlar or something like that. Like the kinds they use in AFVs.

        1. The testing of BEAM should give good data and now they are testing radiation exposure of different materials too.

          Did anyone see this at Instapundit the other day? Body armor goo, that is more protective the faster a projectile is moving. This could be useful in space, if it can withstand the environment.

          Rather than a suit to protect from depressurization, I wonder if a suit could help mitigate radiation. As long as it didn’t restrict movement, it wouldn’t be an impediment.

      3. I wonder how overblown this whole issue is.

        Have we lost an X-37 to MMOD or even came close? And it is covered in a shuttle-type silica tile heat shied that is fully exposed all the time.

        How many total hours in space does that platform have now?

          1. The heat shield on that thing should tell one hell of a tale. Between that and ISS and the LDEF, we should have a pretty good idea what the MMOD environment really is.

  4. I think that NASA would have been wise to specify a certain micrometeoroid flux survival requirement instead of lumping that threat into the loss of crew requirement. It’s kind of similar to how combat damage requirements are typically done for military aircraft: probability of loss of aircraft (PLOA), which is the loss rate due to system malfunctions, is specified independently of mishap rate, which is the loss rate due to all sources including pilot error, weather outside of specified environments, maintenance screw ups, etc. The prime contractor is not usually responsible for mishap rate, although PLOA is almost always a customer requirement, and battle damage / damage tolerance etc. requirements are often levied.

  5. As they pretty much concede, they’re gonna have to give SpaceX and Boeing and waiver if it comes to that, since they really have no alternative. It’s what they’ve done with Soyuz, for the same reason.

    But at least certain NASA staff will feel they’ve justified their paychecks.

  6. There have been a number of articles saying that Boeing and SpaceX aren’t keeping pace as if their vehicles are having problems. But this shows that NASA is the one creating many of these delays and they have not much to do with how well the vehicles will function.

  7. It only matters if someone thinks of it, doncha know? This is why they shouldn’t have such time on their hands.

    A business has a different motivation than govt. regarding safety. Being unsafe costs a business. Being unsafe can be a job opportunity for govt. employees.

  8. 270 crewed flights? To where? ISS? Really? They came up with this number as compared to what? SLS? hahahahahahaha

    Well we’re on flight 2, so far so good….

  9. “They’re going to have difficulty meeting that “precise” number. As I noted in the book, the precision with which they calculate these utterly arbitrary numbers, given the state of knowledge about the system, is absurd.”

    Yes, especially when there were 135 shuttle flights, two losses of crew, and they come up with an LOC probability of 1 in 90. Just sayin…

Comments are closed.