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SpaceX Dragon 2 capsule destroyed in abort motor ground test
Accident Claims SpaceX Dragon Abort Test Capsule Apr 21, 2019 Irene Klotz - Aerospace Daily & Defense Report https://aviationweek.com/space/accid...on-abort-test- capsule This is bad. My guess is at least a year delay for SpaceX commercial crew. Here is hoping that Boeing gets its act together because we need something to replace Soyuz for US crew. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
Jeff Findley wrote on Mon, 22 Apr 2019
07:05:42 -0400: Accident Claims SpaceX Dragon Abort Test Capsule Apr 21, 2019 Irene Klotz - Aerospace Daily & Defense Report https://aviationweek.com/space/accid...t-test-capsule This is bad. My guess is at least a year delay for SpaceX commercial crew. Here is hoping that Boeing gets its act together because we need something to replace Soyuz for US crew. I don't know if we know enough to be talking about how much delay this would inject. The headline makes it sound like the capsule is a dead loss but I don't think we even know that for sure. -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Dryden |
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
"Fred J. McCall" wrote in message ... Jeff Findley wrote on Mon, 22 Apr 2019 07:05:42 -0400: Accident Claims SpaceX Dragon Abort Test Capsule Apr 21, 2019 Irene Klotz - Aerospace Daily & Defense Report https://aviationweek.com/space/accid...t-test-capsule This is bad. My guess is at least a year delay for SpaceX commercial crew. Here is hoping that Boeing gets its act together because we need something to replace Soyuz for US crew. I don't know if we know enough to be talking about how much delay this would inject. The headline makes it sound like the capsule is a dead loss but I don't think we even know that for sure. It looked to me that the capsule had dissappeared after the explosion. Not good. Not good at all. I agree with OP that this could take a year to fix, not to mention the loss of goodwill. I can imagine the knifes are being drawn in Congress. I'm sure this is exactly the thing Boeing / LockMart / ULA have been waiting for. OTOH it would've been infinitely worse if it had happened during a manned test flight. |
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
On 4/22/2019 7:05 AM, Jeff Findley wrote:
This is bad. My guess is at least a year delay for SpaceX commercial crew. Here is hoping that Boeing gets its act together because we need something to replace Soyuz for US crew. Jeff FWIW the conventional wisdom seems to be focusing on the COPV tanks used to fuel the SuperDracos. But this is pure speculation (SWAGs if you will). I have seen ONE still frame taken from a normal speed camera that appears to show an explosion taking place "around" the capsule where the hatch window still appears in the frame. In another video you can see at least two explosions, the first as mentioned where the capsule is largely still intact and a 2nd to the left (from the viewer viewpoint) of the first which appears to blow the capsule off the test stand. Which would tend to indicate multiple possibly cascading explosions. AFAIK know from what has been published in other forums the capsule is believed to be a total loss. Yes this is bad, but the test engineer in me is very happy that this happened during *testing*. Although a RUD is never a welcome event it is a learning opportunity with the net result of an improved design. This is what happened after the Apollo 1 fire. The following block improvements to the Command Module made the follow-ons very different from the original article including the wiring and hatch design from what I have read. It was poor judgement and bad test design that I feel were the real reason behind the fatalities that should not have happened. You could say we were "lucky" that this happened while no crew were on-board, but I *hate* that term. What is proper to say is that an anomaly was caught in testing, just as it should be. What keeps me up at night are the anomaly's that I didn't test for. That is why you do design review after design review and test and test again, and then alter and add to the testing regimen and test again to prove out design margins. Luck as defined simply means you missed a test and found a failure mode at an opportune time. David |
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
David Spain wrote on Mon, 29 Apr 2019 09:01:20
-0400: FWIW the conventional wisdom seems to be focusing on the COPV tanks used to fuel the SuperDracos. Possible, but this seems odd to me. Neither of the fuels is even mildly cryogenic, so what failure mode would there be? This isn't like the Falcon 9 explosion where cryogenic chilling was involved. If it was something like that I would expect it would have to be a 'one off' manufacturing defect of some kind, which would lead to a pretty rapid return to flight. -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Dryden |
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
On 4/29/2019 10:28 PM, Fred J. McCall wrote:
David Spain wrote on Mon, 29 Apr 2019 09:01:20 -0400: FWIW the conventional wisdom seems to be focusing on the COPV tanks used to fuel the SuperDracos. Possible, but this seems odd to me. Neither of the fuels is even mildly cryogenic, so what failure mode would there be? This isn't like the Falcon 9 explosion where cryogenic chilling was involved. If it was something like that I would expect it would have to be a 'one off' manufacturing defect of some kind, which would lead to a pretty rapid return to flight. Let's hope so. Could be a weld issue? Could be a lot of things I suppose. If these things are made in batches it might be informative to pull COPV's from the same build run and check them, maybe run some stress tests on them. It's all SWAG at this point and I'm sure as hell no expert. Could be something else entirely. Conventional wisdom is often wrong. Dave |
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
In article , says...
On 4/22/2019 7:05 AM, Jeff Findley wrote: This is bad. My guess is at least a year delay for SpaceX commercial crew. Here is hoping that Boeing gets its act together because we need something to replace Soyuz for US crew. Jeff FWIW the conventional wisdom seems to be focusing on the COPV tanks used to fuel the SuperDracos. But this is pure speculation (SWAGs if you will). I have seen ONE still frame taken from a normal speed camera that appears to show an explosion taking place "around" the capsule where the hatch window still appears in the frame. In another video you can see at least two explosions, the first as mentioned where the capsule is largely still intact and a 2nd to the left (from the viewer viewpoint) of the first which appears to blow the capsule off the test stand. Which would tend to indicate multiple possibly cascading explosions. AFAIK know from what has been published in other forums the capsule is believed to be a total loss. Yes this is bad, but the test engineer in me is very happy that this happened during *testing*. Although a RUD is never a welcome event it is a learning opportunity with the net result of an improved design. This is what happened after the Apollo 1 fire. The following block improvements to the Command Module made the follow-ons very different from the original article including the wiring and hatch design from what I have read. It was poor judgement and bad test design that I feel were the real reason behind the fatalities that should not have happened. You could say we were "lucky" that this happened while no crew were on-board, but I *hate* that term. What is proper to say is that an anomaly was caught in testing, just as it should be. What keeps me up at night are the anomaly's that I didn't test for. That is why you do design review after design review and test and test again, and then alter and add to the testing regimen and test again to prove out design margins. Luck as defined simply means you missed a test and found a failure mode at an opportune time. I agree with all of this. Also, from what I understand, there is a list of safety related issues that NASA wanted SpaceX to take care of before flying crew on DM-2. The other "silver lining" is that this gives SpaceX more time to take care of those issues as well. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
Jeff Findley wrote on Tue, 30 Apr 2019
14:08:51 -0400: Also, from what I understand, there is a list of safety related issues that NASA wanted SpaceX to take care of before flying crew on DM-2. The other "silver lining" is that this gives SpaceX more time to take care of those issues as well. Would you happen to know what those are or be able to point me to a description of them? -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Dryden |
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SpaceX Dragon 2 capsule destroyed in abort motor ground test
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