SpaceX Successfully Tests Crewed Dragon Launch Abort Engines

An anonymous reader quotes a report from ExtremeTech: SpaceX has cleared a major hurdle on the way to launching manned missions with its Dragon spacecraft. The company had to push back its launch plans after the stunning explosion of a Crew Dragon capsule during testing earlier this year. Now, SpaceX has successfully tested the engines without incident, paving the way for a test flight next year. The SpaceX Dragon is one of two commercial spacecraft NASA hopes to use to launch manned missions to the International Space Station, the other being Boeing's CST-100 Starliner. SpaceX was on track to beat Boeing to launch before its April testing failure, but picking through the pieces of the demolished capsule pushed back the timetable.

After an investigation, SpaceX confirmed the craft's SuperDraco engines themselves were not at fault. These innovative launch abort engines use hydrazine and nitrogen tetroxide propellants, which mix together and ignite, but most launch abort systems use solid propellants. SpaceX went this way because it intends to do propulsive landings with the Dragon in the future, but NASA hasn't authorized that for crewed flights. Unfortunately, a leaky fuel valve in the abort propulsion system allowed nitrogen tetroxide to leak into the helium pressurization system. It was then driven back into the titanium check valve, which caused the explosion. The new and improved Dragon has a burst disk in the fuel lines that keeps propellant from leaking into the high-pressure lines before ignition. This week's test-firing demonstrates that the new system functions as intended, and SpaceX says it can now move forward with launch plans. The next step is to test the SuperDraco engines in-flight later this year. Then, once SpaceX can prove that its spacecraft can handle an in-flight abort, it'll prepare for the first crewed flight in early 2020.

bittersweet

[Chromal]

I'm glad if they were able to resolve the issue by replacing some parts with rupture discs, but sad to see the vision of a self-landing dragon module fade away. But pragmatically think they made the right call and can always revisit the self-landing capability in another block revision.

Re:

[SpaceDave]

I can't see them spending too much time improving the capabilities of Dragon if their plan is to eventually make it redundant with Starship. Dragon is adequate as it is for ISS resupply etc, so there's not a lot of incentive to upgrade it. In the end, Dragon is just a step towards the real goal - heavy-lift launches and interplanetary spacecraft.

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[Kjella]

I can't see them spending too much time improving the capabilities of Dragon if their plan is to eventually make it redundant with Starship. Dragon is adequate as it is for ISS resupply etc, so there's not a lot of incentive to upgrade it. In the end, Dragon is just a step towards the real goal - heavy-lift launches and interplanetary spacecraft.

The real step for Dragon is finding out exactly how many hoops they must jump through to get a man-rating. SpaceX knows those goal posts are somewhat arbitrary, like the SLS is going man-rated with way less launches because they create more paperwork saying it won't blow up. There's very little penalty at NASA for being very conservative and a huge potential PR disaster if anything goes wrong with astronauts on board. Once they have an approved stack it'll be so much easier for SpaceX to just point to the o

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[Gavagai80]

NASA ruled out propulsive landing long before the accident. The reason SpaceX decided to go with burst discs is that they'd given up on ever getting permission to land propulsively because of NASA's lack of interest and refusal to certify it.

They've also given up on getting NASA permission to re-use Crew Dragon with astronauts. It'll only re-fly after be modified to a cargo version. Getting permission to do anything new or unusual with astronauts on board is virtually impossible, so better not to waste mone

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[Chromal]

The reason SpaceX decided to go with burst discs is because the Dragon capsule blew up on the pad this summer. Once the determination was made that this would have prevented the problem, they made the revision to the hardware. If NASA wants to buy more crewed Dragon modules for NASA missions, then SpaceX will sell NASA more of them and perhaps even buy them back afterwords for reuse on private or commercial spaceflight missions.

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[Namarrgon]

The reason SpaceX decided to go with burst discs is because the Dragon capsule blew up on the pad this summer.

That's what pointed them at the faulty valve system in the first place, yes, but GP was referring to their choice of solution.

They could've opted to fix it with a more expensive and fully-reusable fix, but - given that NASA would not sign off on reusing a Crew Dragon at all - they chose to go with the non-reusable but cheap and reliable burst discs instead. They'd originally envisioned offering cheap & reusable crewed spacecraft seats, with Crew Dragon touching down propulsively on land for fast refurb,

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[Agripa]

Aren't the burst disks installed in addition to the existing valves so that it is still reusable in the sense that the engines operate like they did but after the first operation, the burst disks are opened and would be replaced during the normal maintenance and inspection cycle?

In other news...

[joh]

NASA has just published the cost for launching astronauts per seat: It's $55 million for SpaceX Dragon and $90 million for Boeing Starliner (which is more than NASA pays per seat on the Russian Soyuz). Boeing also got an extra $287.2 million because they threatened to pull out altogether. SpaceX got nothing extra.

I hope at least Boeing invested the millions into better software than in their airplanes.

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[Canberra1]

SpaceX certainly has experienced experts that nail defects with amazing attention to detail. looking back, they publish their findings too, and do not contrive lame excuses. Boeing shed their best people, so who knows - other than they do take risky shortcuts with respect to one airliner. As for costs, Boeing has a history of being more expensive.

Re:In other news...

[JoshuaZ]

First, one shouldn't assume that anything is going to happen until they've actually gotten at least one to the ISS. The entire point of there being two different contractors is that if one couldn't manage things on time then the other might. Since both are years behind schedule, that doesn't seem at all crazy. Similarly, this also makes sure that if something later goes drastically wrong with either Dragon or Starliner that there will still be access with one while the other remains grounded.

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[JoshuaZ]

They've learned a few things from the shuttle program.

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[Ol Olsoc]

Stupid NASA and Boeing! Why even bother with any other company except for SpaceX? It is quite plain that only SpaceX knows what they are doing!

The Spacex fans do have their hubris. See how they have made the dragon capsule failure NASA's fault?

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[Gavagai80]

It's nothing compared to the money and bonuses Boeing rakes in for a decade of failing to make SLS rockets. Perhaps with a little more money they'll be able to hire someone to check if parachute pins are inserted.

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[im_thatoneguy]

For real. When we have a big client dumping cash on us and they come to us with a small project, we don't nickle and dime them. Boeing should have wrapped in their bullshit payment for deliverable in the original bid if for no reason other than as a thank you for a decade of SLS pork.

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[mschaffer]

That's because Boeing's capsule doesn't explode. You need to pay extra for that.

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[F.Ultra]

Perhaps they have to perform even a single test flight before you can make that assertion.

A question to /.

[Nexion]

So, you have to travel up to the space station and you have two choices before you. You can ride up on a Boeing Starliner or you can ride up on a Dragon capsule. Think about your safety in doing so. Do you want something dependable or would you risk something flashy?

Me? I'd rather go up on something that has delivered for decades, but these new options are our choices. Do you go with the one or the other? What is your choice? Why?

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[cmseagle]

I have a hard time convincing myself of Boeing's engineering abilities given the way that corporate cancer has impacted their aircraft division. Even with capable engineers, I don't have confidence that the management failures aren't affecting the safety and reliability of Starliner. I'd pick the Dragon capsule, as an armchair astronaut.

Good question!

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[r2kordmaa]

They are pretty much equal in terms of safety, very similar concepts built to same standards and both lacking in any significant flight history. Maybe you could say SpaceX has more recent experience with launching capsules, but Dragon is not the same thing as Dragon 2, so it doesn't necessarily carry over. Anyway, given an opportunity to fly to ISS I probably wouldn't worry too much about safety, it's not like any of the capsules are complete deathtraps and the reward I'd say is worth the risk.

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[Jeremi]

I don't think that the average Slashdotter is remotely qualified to make a meaningful risk assessment.

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[cbhacking]

If cost was no object at all? Starliner, honestly; Boeing has an awe-inspiring capacity to burn money but their rockets are top-notch safety-wise (perfect record on the Atlas V) and I'm hopeful that their capsules take more from their rocketry than their airliners in this regard (while the failed parachute deployment was concerning, parachutes are hard; SpaceX has had plenty of trouble with them too).

If I had to pay even 0.1% of the total cost myself, Crew Dragon. Heck, if you raise the cost to a full 1%, I