13
$\begingroup$

Given that SpaceX's Dragon has been designed to be reusable ("with minimal rework and fueling"), why hasn't it been, in fact, reused?

We've had 6 CRS missions bringing Dragon to ISS and back home (and a few Dragon test missions before that), but as far as I know (can't find source now), only CRS-11 will fly on a reused Dragon.

Why?

This might be speculative, but is there a good reason not to? Is there a NASA decision that prevents them from doing so? Or is it just risk management? (Or, heavens forbid, are recovered Dragons in a really bad condition?)

$\endgroup$
15
$\begingroup$

The NASA contract for the CRS missions specified a new Dragon for each flight.

That would explain why no Dragon has been reused on an ISS logistics mission.

But that does not answer why SpaceX has not reflown any of the others, which they retain ownership of, post flight.

SpaceX has proposed a commercial free flyer, where a Dragon would be launched with experiments and called DragonLab, reside in orbit some period of time, then return. The current launch manifest for SpaceX shows two such missions on the list, but without dates.

I heard Max Vozhoff on the SpaceShow talk about plans for DragonLab. They had suggested offering the Department of Ed, an option to buy an entire Dragon flight, and offer a competition for students from all states to supply experiments. But that never seems to have materialized.

It has been reported that components of Dragon's have been reflown, but not specifics of which components.

The CRS-11 missions in 2017 and pretty much all future Dragon Cargo are expected to be the first to refly a Dragon to the ISS.

Additionally the first few Dragon attempts were learning experiences, and changes were made based on lessons learned. There was a leaking problem with water after landing in one of the Dragons, and changes to the power/refrigeration systems in later models. It may be they need to stabilize on a design as mainly static before reusing.

Dragon V2 will probably be a different story, being planned for reuse from the start, based on many previous Dragon cargo flights and years of testing and upgrading.

As of Jun 2018, 3 Dragons have been reflown with number 4 due at the end of the month. CRS-11 and CRS-13 used the same booster (Core B1035). CRS-12 and CRS-14 used the same booster (Core B1039).

CRS-15 is reusing the booster (Core B1045, last Block 4) from the TESS mission.

Reused capsules on reused boosters oh my!

$\endgroup$
  • 1
    $\begingroup$ Here's an idea: they could launch a reused Dragon on a reused Falcon 9 booster. Then recover both. That would be cool. $\endgroup$ – radex Jan 6 '16 at 19:12
  • 2
    $\begingroup$ @radex darn tootin! $\endgroup$ – geoffc Jan 6 '16 at 19:12
  • 1
    $\begingroup$ I am guessing using a used first stage a few times, and a used dragon a few times might at the most half the costs, since you still have all the work with the current process flow and you are still chucking away lots of expensive hw (entire 2nd stage, solar panels, etc.). So I am guessing a launch like that might be 30+ million - assuming SpaceX really can do a minimal Falcon 9 for 60 million. Which is dubious as well. $\endgroup$ – Mike Wise Jan 7 '16 at 13:17
  • 1
    $\begingroup$ @MikeWise FWIW SpaceX offers Falcon/Dragon flights to NASA for much more, 100-something million per flight. $\endgroup$ – radex Jan 8 '16 at 8:35
  • 1
    $\begingroup$ True but the actual cost to SpaceX of a flight is better reflected by their price to the wider market. NASA has a lot more paperwork and other requirements that are intended to ensure quality and safety but that the commercial world deems unnecessary. So NASA flights cost a lot more. $\endgroup$ – Mike Wise Jan 8 '16 at 8:48
4
$\begingroup$

The early Dragons had significant saltwater incursion after splashdown - not to the extent that it endangered the cargo, but enough to impact reusability. This has improved over time but making everything completely immune to the sea costs mass and development time.

$\endgroup$
3
$\begingroup$

You've also got the factor in that the cost of reliable reusable components is much higher than single use ones, since they have to withstand much more abuse. This is one reason why Russia never seriously considered picking up the Buran programme again. Soyuz production and launches have been honed to a fine art, and it'd be very difficult to make a reusable system that's cost competitive and can be turned around as fast as a new Soyuz can roll off the production line. Wasteful? Yes. But also cost-effective in terms of cold, hard cash and production realities.

There are good elements about the Dragon though, and I personally suspect they will be kept and that in the long run the basics will be retained, but rationalised and cost reduced into a single-use, serial production unit — provided the US decides to stay in the human spaceflight game, which is debatable. If not the Dragon module might well be licenced out to other operators who will mount it (as a single use disposable) on their own launchers — Jaxa seems a likely candidate — much as China uses a modified Soyuz crew section on a Long March launcher.

$\endgroup$
  • $\begingroup$ The basics premise of this post contradicts the documentation for the Dragon program and other answers without providing any evidence for the difference. The information about Soyuz as presented is heresay but probably true enough. After that this turns entirely speculative without offering any references or other backing. $\endgroup$ – Caleb Mar 20 '17 at 9:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.