Thanks, that is good news indeed! I wonder if we will ever find out exactly what the issue was. At least the implication seems to be that the SuperDraco thrusters have no issues.
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Report from SpaceX on the cause of the recent Crew Dragon anomaly during ground testing of the DM-1 capsule after recovery.
UPDATE: IN-FLIGHT ABORT STATIC FIRE TEST ANOMALY INVESTIGATION
Cause of the explosion, quote: “the anomaly occurred approximately 100 milliseconds prior to ignition of Crew Dragon’s eight SuperDraco thrusters and during pressurization of the vehicle’s propulsion systems. Evidence shows that a leaking component allowed liquid oxidizer – nitrogen tetroxide (NTO) – to enter high-pressure helium tubes during ground processing. A slug of this NTO was driven through a helium check valve at high speed during rapid initialization of the launch escape system, resulting in structural failure within the check valve. The failure of the titanium component in a high-pressure NTO environment was sufficient to cause ignition of the check valve and led to an explosion...
It is worth noting that the reaction between titanium and NTO at high pressure was not expected. Titanium has been used safely over many decades and on many spacecraft from all around the world.”
And the good news, quote: “SpaceX has already initiated several actions, such as eliminating any flow path within the launch escape system for liquid propellant to enter the gaseous pressurization system. Instead of check valves, which typically allow liquid to flow in only one direction, burst disks, which seal completely until opened by high pressure, will mitigate the risk entirely. Thorough testing and analysis of these mitigations has already begun in close coordination with NASA, and will be completed well in advance of future flights.”
UPDATE: IN-FLIGHT ABORT STATIC FIRE TEST ANOMALY INVESTIGATION
Cause of the explosion, quote: “the anomaly occurred approximately 100 milliseconds prior to ignition of Crew Dragon’s eight SuperDraco thrusters and during pressurization of the vehicle’s propulsion systems. Evidence shows that a leaking component allowed liquid oxidizer – nitrogen tetroxide (NTO) – to enter high-pressure helium tubes during ground processing. A slug of this NTO was driven through a helium check valve at high speed during rapid initialization of the launch escape system, resulting in structural failure within the check valve. The failure of the titanium component in a high-pressure NTO environment was sufficient to cause ignition of the check valve and led to an explosion...
It is worth noting that the reaction between titanium and NTO at high pressure was not expected. Titanium has been used safely over many decades and on many spacecraft from all around the world.”
And the good news, quote: “SpaceX has already initiated several actions, such as eliminating any flow path within the launch escape system for liquid propellant to enter the gaseous pressurization system. Instead of check valves, which typically allow liquid to flow in only one direction, burst disks, which seal completely until opened by high pressure, will mitigate the risk entirely. Thorough testing and analysis of these mitigations has already begun in close coordination with NASA, and will be completed well in advance of future flights.”
N5329K
Active Member
Nitrogen tetroxide has always been nasty stuff to deal with. In a book I wrote (Hostile Waters) about the sinking of the Soviet missile submarine K-219, leaking nitrogen tetroxide, mixed with seawater, which made nitric acid that ate right through a missile body, releasing the hydrazine rocket fuel (which is hypergolic with N2O4), causing an explosion inside a silo, and nearly created a "Chernobyl in the Gulf Stream" that would have made the beaches of North Carolina glow. This was in 1986.
It's still nasty stuff.
Robin
Great looking read, Hostile Waters (the sinking of K-219) will be my next read. Just finished Project Azorian (the raising of K-129), so will be a great follow up.
I'm betting the Russian subs no longer use 1, 2 or 9 numbering their subs.
That part is not explained. What “component” leaked? The statement does not name the component, but surely that is another point of failure. It’s not just about the NTO igniting the titanium check valve; that would not have happened if there had been no “leaking”.
I'm guessing the one way valve leaked allowing NTO to get in the piping between the one way and main valve. Then that slug of liquid accelerated and slammed into the valve when the system pressurized. With the burst disks, the NTO is completely isolated until the system is activated with high pressure He.
N5329K
Active Member
Nikxice
Active Member
Certainly the Commercial Crew news of the day is the preliminary reveal by SpaceX of the DM-1 investigation. Perhaps lost in the news cycle are the recent BS remarks made to Space News by Jim Bridenstine concerning SpaceX and their lack of communication. Interesting that Boeing's Starliner abort system leak anomaly continues to playout with a secrecy pass from NASA. Was starting to warm up to this NASA administrator as a possible good guy. I've now got Jimbo back on my "wary" list.
SpaceX's response to Crew Dragon explosion unfairly maligned by head of NASA
SpaceX's response to Crew Dragon explosion unfairly maligned by head of NASA
e-FTW
New electron smell
Sounds like there will be a conclusion to the Crew Dragon anomaly. SpaceX will hopefully get back on track. In Flight Abort in October or November hopefully.
SpaceX’s Crew Dragon explosion investigation almost complete, says executive | TESLARATI
SpaceX’s Crew Dragon explosion investigation almost complete, says executive | TESLARATI
Boeing's Starliner delayed. Sometime in 2020...
Boeing’s Starliner Commercial Spacecraft Won’t Take Off To The International Space Station Before 2020
Boeing’s Starliner Commercial Spacecraft Won’t Take Off To The International Space Station Before 2020
Nikxice
Active Member
Good find @Grendal. It looks as though the mainstream Space media has yet to pick up on this Starliner delay. Following a link from that "Mashable India" article there's a curious mention of NASA's recent management changes. From "Timesnownews.com", The Boeing Starliner mission was originally scheduled for this month, but that has been delayed to at least the end of the year or into 2020 due to technical issues and amid a shakeup in the top echelons of the space agency. The shakeup is probably referencing the Bill Gerstenmaier demotion, which only leaves us with more questions than answers.
The bottom line is Boeing's Starliner program is pushed out at least another six months. It also appears that SpaceX is back in the lead for launching the first Commercial Crew, presently recovering from their own six months of "technical issues".
The bottom line is Boeing's Starliner program is pushed out at least another six months. It also appears that SpaceX is back in the lead for launching the first Commercial Crew, presently recovering from their own six months of "technical issues".
e-FTW
New electron smell
Huh???
Title of article says at least 2020, body of article says
The source article states the original schedule was this month so the delay is a minimum of 4 months.
It seems like having your human rated capsule destroy itself four months ago rates better than air quotes. They also had a parachute test failure in April.
Nikxice
Active Member
I deliberately understated the seriousness of those "technical issues". It was a swipe at the quote in the article where it referred to the technical issues experienced by Boeing's Starliner. As you're probably aware, Starliner also had a critical engine abort system failure, along with parachute anomalies similar to those of SpaceX's Dragon 2 capsule
However, you've busted me on the calendar. I thought I could get away with adding two months to that apparent 4 month Starliner delay. Can't bear to think we've already reached the end of summer!
Nikxice
Active Member
Poking around the internet this morning, I couldn't find a reliable U.S. news source confirming a further extensive delay for Starliner. Thoughts are that the foreign reporter might be confusing the flights/dates for previously published timelines. I recall earlier this year Boeing was looking at around April for their uncrewed Starliner mission and this August for crewed. The reporter's delay comment about the end of year, into 2020, was likely meant to be a reference to the original August crewed mission. The earliest date I could find for the uncrewed Starliner is this September 17th, but wouldn't be surprised if that gets pushed.
e-FTW
New electron smell
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