DocM Posted July 20, 2015 Author Share Posted July 20, 2015 Inconel is an iron-nickel-cobalt-titanium superalloy which is incredibly tough. It's used for printing SuperDraco engines. The Dragon spacecraft would have survived if it had been programmed to deploy its parachutes after the vehicle broke up (even without SuperDraco abort engines !!), and from now on the software will support this safety mode. Link to comment Share on other sites More sharing options...
Andrew Lyle Global Moderator Posted July 20, 2015 Global Moderator Share Posted July 20, 2015 I'm glad they discovered what the issue is (maybe) and are looking into replacing the sup pier of the struts. Hopefully they'll stick to their expected launch schedule for September Link to comment Share on other sites More sharing options...
DocM Posted July 20, 2015 Author Share Posted July 20, 2015 There's only one v1.1 launch remaining, Jason 3 at Vandenberg, but if it's before the v1.2 maiden flight or not is up for grabs. Link to comment Share on other sites More sharing options...
Draggendrop Veteran Posted July 20, 2015 Veteran Share Posted July 20, 2015 Article released..... In a teleconference with reporters, Elon Musk said the preliminary conclusion of the three-week investigation was that a steel strut, designed to hold a bottle of helium in place within the upper stage Link to comment Share on other sites More sharing options...
DocM Posted July 21, 2015 Author Share Posted July 21, 2015 Images of what we're discussing. COPV = Composite Overwrapped Pressure Vessel Basic struts COPV installation in S2 LOX tank A Falcon 9 upper stage COPV that survived reentry and fell in Brazil Link to comment Share on other sites More sharing options...
DocM Posted July 21, 2015 Author Share Posted July 21, 2015 Interesting.... http://www.spacex.com/news/2015/07/20/crs-7-investigation-update > As noted above, these conclusions are preliminary. Our investigation is ongoing until we exonerate all other aspects of the vehicle, but at this time, we expect to return to flight this fall and fly all the customers we intended to fly in 2015 by end of year. > Link to comment Share on other sites More sharing options...
Unobscured Vision Posted July 21, 2015 Share Posted July 21, 2015 Overpressure, just not the way we would think it could happen. Wow. And a strut failing like that is sure to put the supplier out of business just from the lawsuit(s) alone. Not sure if the information is publicly available on who made the strut, or the Engineering Data for that piece. Probably not, though I'd love to take a look at it. It has to be a company in the United States in order to clear Mil/Gov Certification requirements. I doubt that information is just going to be accessible to anyone who'd want it. So, we'll just go on what we've been told in the release. A strut rated at 10k failed at 20% load, most likely from material defect. The rest of the assembly, not designed to compensate for a failure (since it shouldn't happen) simply did its' job but the COPV tank mounted inside the LOX tank broke loose, ruptured, and then overpressurized the LOX tank. Even if that happened 20 minutes later, after the S2 had been fired and most of the LOX had been used up, that stage would have hosed and unusable. That Merlin-D would never have fired up again; or if it had, it would have exploded. Likely there are safety checks to prevent an explosion event if the LOX supply were "tainted" by the COPV supply, but at least the overpressure event wouldn't occur. It would still mean the Dragon and its' cargo wouldn't make it to the ISS, forcing an abort and return to Earth. Yeah, bad stuff. At least it was a "sure thing" that the Dragon survived intact and the ground received data from it for as long as they had Line of Sight. I wonder what ultimately happened to it. Link to comment Share on other sites More sharing options...
DocM Posted July 21, 2015 Author Share Posted July 21, 2015 This Dragon 1 hit the water at terminal velocity. In the future they'll be programmed to deploy the chutes if F9 breaks up. Cargo Dragon 2 will also fly, with SuperDracos and parachutes. ....but the COPV tank mounted inside the LOX tank broke loose, ruptured, and then overpressurized the LOX tank. > No sign that the COPV ruptured. http://www.aviationweek.com/space/musk-outlines-suspected-root-cause-falcon-9-failure > In a teleconference with reporters, Musk said the upper stage exploded while the first stage was still firing after a high-pressure helium bottle broke loose in the upper stage Link to comment Share on other sites More sharing options...
Unobscured Vision Posted July 21, 2015 Share Posted July 21, 2015 Oh, excuse me. I thought the COPV tank itself ruptured once it broke loose. I forgot how buoyant Helium actually is, even at 5,500 psi. Liquid in a liquid will still obey density differences, no matter what pressure it's at. So yeah, it probably floated to the top of the LOX tank, and from there all hell broke loose (literally) because it still hit the top of the LOX tank with the mass of 5,500 psi of Helium plus the mass of the COPV tank .. yeah, overpressure time for the LOX tank. Sometimes all it takes is a light tap with those kinds of forces and that kind of cold, as DD will be familiar with. If that COPV tank was moving around the LOX tank, and impacted the sides or the top with enough force, it could cause a defect and a rupture point too. Draggendrop 1 Share Link to comment Share on other sites More sharing options...
FloatingFatMan Posted July 21, 2015 Share Posted July 21, 2015 I bet Elon was pretty steamed at that supplier... Link to comment Share on other sites More sharing options...
Unobscured Vision Posted July 21, 2015 Share Posted July 21, 2015 I bet Elon was pretty steamed at that supplier... I'm not sure "steamed" is enough to describe how truly p***ed off Elon, the rest of SpaceX, NASA, Boeing, and the Aerospace Industry in general is at that supplier right now. Sepeiku with rusty steak knives, toothpicks and horribly inefficient spoons are probably being planned for tomorrow at the supplier's headquarters as we speak. Link to comment Share on other sites More sharing options...
FloatingFatMan Posted July 21, 2015 Share Posted July 21, 2015 I'm not sure "steamed" is enough to describe how truly p***ed off Elon, the rest of SpaceX, NASA, Boeing, and the Aerospace Industry in general is at that supplier right now. Sepeiku with rusty steak knives, toothpicks and horribly inefficient spoons are probably being planned for tomorrow at the supplier's headquarters as we speak. I'm English, understating things comes with the territory. Unobscured Vision 1 Share Link to comment Share on other sites More sharing options...
Draggendrop Veteran Posted July 21, 2015 Veteran Share Posted July 21, 2015 The "counter intuitive" is what really bothered me...still does a bit until Elon clarifies the "readings" which ultimately lead to this statement. With out further info, and going on the articles data, imho, I have to lean on the idea that the strut broke due to metallurgical issues, tank rattle and eventual displacement which caused contents to dump before contact reseal of lines and the increased pressure in the LOX tank was now above rating and blew. This may have shown as COPV pressure decrease (during prechill sequence) and abrupt sealing, as LOX tank pressure increase (in stage 2)....while stage 1 was still in it's phase...giving the headshake in instrumentation for .9 seconds. SpaceX has to get back launching, and an increased launch schedule as mentioned can be done with this time punching out cores and assembly till then.....Hope for the best...These guys are GOOD.... Sad to hear about the "heavy" delay Watch everyone else learn from this and have chute capability on launch.....Cheers Unobscured Vision 1 Share Link to comment Share on other sites More sharing options...
Unobscured Vision Posted July 21, 2015 Share Posted July 21, 2015 I'm English, understating things comes with the territory. As you wish, Lord Baron. Link to comment Share on other sites More sharing options...
DocM Posted July 21, 2015 Author Share Posted July 21, 2015 Almost forgot: Musk also said that SpaceX's fleet will deploy ROV's (submersibles) to search for S2 debris. Link to comment Share on other sites More sharing options...
Draggendrop Veteran Posted July 21, 2015 Veteran Share Posted July 21, 2015 Another article on the probable cause.....interesting points.... Several helium tanks, each pressurized to about 5,500 pounds per square inch, are mounted inside the rocket Link to comment Share on other sites More sharing options...
Draggendrop Veteran Posted July 21, 2015 Veteran Share Posted July 21, 2015 Falcon Heavy delay..... Link to comment Share on other sites More sharing options...
DocM Posted July 21, 2015 Author Share Posted July 21, 2015 Strut rating: 10,000 lb Absolute margin: 4-8x rating (expected fail point) Strut failed at 2,000 lb Yeah...that's a serious production quality issue. Link to comment Share on other sites More sharing options...
Unobscured Vision Posted July 21, 2015 Share Posted July 21, 2015 Bleowch. And dammit. Link to comment Share on other sites More sharing options...
anthdci Posted July 22, 2015 Share Posted July 22, 2015 I am going to orlando for my honeymoon around April time next year. Could I get lucky and it coincide with the first falcon heavy launch Link to comment Share on other sites More sharing options...
FloatingFatMan Posted July 22, 2015 Share Posted July 22, 2015 I am going to orlando for my honeymoon around April time next year. Could I get lucky and it coincide with the first falcon heavy launch I tried that on my honeymoon 16 years ago. I was even lucky that were was going to be a launch whilst I was there, but when it came down to it, I just couldn't go to the launch... Last time I went to one, the Challenger exploded. Guess it's still bothering me! Link to comment Share on other sites More sharing options...
anthdci Posted July 22, 2015 Share Posted July 22, 2015 I tried that on my honeymoon 16 years ago. I was even lucky that were was going to be a launch whilst I was there, but when it came down to it, I just couldn't go to the launch... Last time I went to one, the Challenger exploded. Guess it's still bothering me! I've wanted to see one for years but the last time we were there I was under 25 so the extra insurance on a hire car made it far too expensive so I couldn't get there. My other half isn't all that bothered by it thought so I doubt she'd want to drive all the way there for a scrubbed launch. Link to comment Share on other sites More sharing options...
Draggendrop Veteran Posted July 24, 2015 Veteran Share Posted July 24, 2015 A candid reminder on complacency..... The explosion of a SpaceX rocket during a space station resupply mission last month jolted the company awake in some ways, CEO and founder Elon Musk said. Prior to the June 28 Falcon 9 rocket explosion Unobscured Vision 1 Share Link to comment Share on other sites More sharing options...
flyingskippy Posted July 24, 2015 Share Posted July 24, 2015 If only NASA would have sent out an email asking if there is any reason at all to delay the launch of Challenger. Got to give props to SpaceX for having such a candid open floor policy. It isn't as common as it should be in the aviation/aerospace industry. Unobscured Vision and Draggendrop 2 Share Link to comment Share on other sites More sharing options...
DocM Posted July 24, 2015 Author Share Posted July 24, 2015 Interesting stuff going on. NSFers report http://forum.nasaspaceflight.com/index.php?topic=36326.5150 a west coast crew appears to be training recovery ops with a used Dragon two east coast support ships appear to be sailing a search pattern that indicates the use of side-scan sonar. Together with Musk's statements about using an ROV to search for CRS-7 debris, it appears the hunt is still on to find S2 and perhaps the Dragon. Unobscured Vision 1 Share Link to comment Share on other sites More sharing options...
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