SpaceX Says Nitrogen Tetroxide Leak Resulted in Destruction of Crew Dragon Vehicle
HAWTHORNE, Calif. (SpaceX PR) — On Saturday, April 20, 2019 at 18:13 UTC, SpaceX conducted a series of static fire engine tests of the Crew Dragon In-Flight Abort test vehicle on a test stand at SpaceX’s Landing Zone 1, Cape Canaveral Air Force Station in Florida.
Crew Dragon’s design includes two distinct propulsion systems – a low-pressure bi-propellant propulsion system with sixteen Draco thrusters for on-orbit maneuvering, and a high-pressure bi-propellant propulsion system with eight SuperDraco thrusters for use only in the event of a launch escape. After the vehicle’s successful demonstration mission to and from the International Space Station in March 2019, SpaceX performed additional tests of the vehicle’s propulsion systems to ensure functionality and detect any system-level issues prior to a planned In-Flight Abort test.
The initial tests of twelve Draco thrusters on the vehicle completed successfully, but the initiation of the final test of eight SuperDraco thrusters resulted in destruction of the vehicle. In accordance with pre-established safety protocols, the test area was clear and the team monitored winds and other factors to ensure public health and safety.
Following the anomaly, SpaceX convened an Accident Investigation Team that included officials from the National Aeronautics and Space Administration (NASA), and observers from the Federal Aviation Administration (FAA) and the National Transportation Safety Board (NTSB), and began the systematic work on a comprehensive fault tree to determine probable cause. SpaceX also worked closely with the U.S. Air Force (USAF) to secure the test site, and collect and clean debris as part of the investigation. The site was operational prior to SpaceX’s Falcon Heavy launch of STP-2 and landing of two first stage side boosters at Landing Zones 1 and 2 on June 25, 2019.
Initial data reviews indicated that 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.
In order to understand the exact scenario, and characterize the flammability of the check valve’s titanium internal components and NTO, as well as other material used within the system, the accident investigation team performed a series of tests at SpaceX’s rocket development facility in McGregor, Texas. Debris collected from the test site in Florida, which identified burning within the check valve, informed the tests in Texas. Additionally, the SuperDraco thrusters recovered from the test site remained intact, underscoring their reliability.
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. Even so, the static fire test and anomaly provided a wealth of data. Lessons learned from the test – and others in our comprehensive test campaign – will lead to further improvements in the safety and reliability of SpaceX’s flight vehicles.
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.
With multiple Crew Dragon vehicles in various stages of production and testing, SpaceX has shifted the spacecraft assignments forward to stay on track for Commercial Crew Program flights. The Crew Dragon spacecraft originally assigned to SpaceX’s second demonstration mission to the International Space Station (Demo-2) will carry out the company’s In-Flight Abort test, and the spacecraft originally assigned to the first operational mission (Crew-1) will launch as part of Demo-2.
Editor’s Note: SpaceX held a media telecon about the accident today. “We’ll fly when we’re ready,” said SpaceX VP of Build & Flight Reliability Hans Koenigsmann. In other words, they don’t have a launch date they’re confident enough to share with the public.
In addition to dealing with implementing and testing changes resulting from the explosion, SpaceX is also having to work through a number of other issues before flying astronauts to the space station aboard a Crew Dragon.
Between the changes and the other work, it’s looking increasingly unlikely that they will get a Crew Dragon flight test to station this year. They might be able to do the in-flight abort test, but that is uncertain as well.
83 responses to “SpaceX Says Nitrogen Tetroxide Leak Resulted in Destruction of Crew Dragon Vehicle”
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No “complete re-design” is required to resolve this issue and press forward with the inflight abort and demo mission 2.
And that is certainly good news!
we will see
Are you suggesting the whole vehicle may have to be redone? Or the complete high pressure system?
My reading of the release suggests that the high pressure system needs work. Any high pressure oxidizer in contact with titanium is extra bad and must be prevented under any conditions. That should be very clear in hindsight. I think another shaker test should be done after the fixes are done and before flight.
My reading is that they should be able to fly fairly soon even with more testing.
no but I suspect the entire notion of the super draco plumbing is going to be redone. they are six months to ayear away from flying
they are lucky this didnt happen in a vehicle with people in it
I’m reading it as a fairly straightforward fix of a single component problem. Serious testing after the fix should be in the cards to find any other issues. My guess is four to six months. Fortunately, we will know very quickly what the schedule will be.
Very lucky. It’s crazy how one single issue can change everything.
I read it the same way.
If it was me, I’d make the component swaps on the D2 unit to be used for the in-flight abort test, then use that modified new capsule to re-run the “paint shaker” test that went awry on April 20, then fly the in-flight abort test with it, then stick the recovered capsule back on the “paint shaker” for a second go-around.
In parallel, the same component updates can be made to all other D2 vehicles that are in-process on the production line and the parachute issues remaining – whatever they are alleged to be – can be addressed along with any other action items on NASA’s list.
There’s still five and a half months left in the year. I don’t see any reason, at this point, to categorically rule out a DM-2 flight before year’s end.
well we will see.
clearly they must have tested the DRaco’s full up before in some sort of mockup…wonder why this problem did not emerge then.
we will see where this goes…they are in my view through for the year.
Boeing has the green light to be first 🙂
Just a guess on my part, but the lack of such a problem in previous tests of SuperDracos – of which there were many – might well have to do with those tests not being conducted on a “paint shaker” platform. SpaceX has already said the check valve involved in the explosion was of a type that incorporates a spring. Springs have natural harmonics as do the masses they impinge upon. As noted by SpaceX during the run-up to the first Falcon Heavy launch, complex vibration environments are difficult to model completely anent their interactions with complex systems. The Boeing Starliner abort system test mishap seems to indicate that Boeing is in no better shape than Spacex anent ability to accurately model all possible acoustic/vibration interactions with and within its systems.
I will take your “view” of SpaceX’s chances of still launching people to ISS this year – or at least ahead of Boeing – with the hogshead of salt it deserves. After all, only a few days ago you were still insisting SpaceX had “no idea” what had caused the D2 explosion.
Without going into all the back and forth I put the chances of Boeing first with astronauts at 2 to 3. I offer a small bet at 3/2 odds that SpaceX puts people on ISS before Boeing. Loser donates to Parabolic arc. My $30.00 against your $20.00. Sent on confirmation and agreement.
And no, I would not have offered this last week.
From the detailed description that SpaceX has released, it sounds like the NTO check valve will be replaced with a burst disk. That sounds relatively simple to me.
We don’t really know enough details to know if they were “lucky” to find this during testing, or if it was bound to happen during testing. In addition to this ground test, they still plan on performing an in flight abort test.
I don’t know if I’d call their description “detailed”. No functional diagrams of the plumbing. No listing of pressures. No detailed timeline (to the millisecond). No description of the propellant loading process and capsule handling. No description of what operation actually caused the NTO ingestion. No description of the inspections to ensure propellant didn’t migrate (did they even inspect it AT ALL?). No before/after images of accident hardware. No photo comparison to test hardware when they reproduced the failure. No complete fault tree. No list of other changes to be implemented. No description if this is the way it flew to ISS. No description if this is how it returned from ISS.
When I get a ‘detailed’ description of a failure investigation, I want ‘the details.’
Unfortunately, we’re not going to get that level of detail for either of the commercial crew vehicles. All of those details are proprietary. That’s one of the downsides to commercial procurement of vehicles rather than NASA developing their own.
Which is true, but let’s call a spade a spade. We’re not gonna get ‘detailed’ descriptions from any of these companies. We’re gonna to get the minimum needed for these organizations to show they’ve found root cause – and that’s it.
If “we” is the general public, I’m sure that you’re right. They won’t be able to use “proprietary information” as a reason to withhold that kind of information from the other stakeholders. Without NASA (and probably the USAF) they don’t fly government missions. Without the FAA, they don’t fly at all. I do trust that they are being straightforward with all the stakeholders in this case but I wonder when the vehicle is Starship, built without government help, if they would feel the need to be so forthcoming. Probably.
I have no idea why you would insinuate any desire on SpaceX’s part to withhold information about the D2 failure from NASA or any other governmental party with need-to-know. NASA personnel were present when the test went awry and have been heavily involved in the investigation since. Trying to keep anything from NASA would be effectively impossible. The NTSB has also been brought in and those guys are real bloodhounds too.
The need-to-know list, for what it’s worth, probably doesn’t include USAF and FAA. SpaceX is never going to be flying D2 for USAF so there is no obvious reason to loop them in. And, despite a seemingly widespread misapprehension to the contrary, the FAA has no role in vetting the engineering of spacecraft, just in granting licenses to poke holes in U.S. airspace for launches and re-entries.
If there are ever any SHS mishaps, NASA wouldn’t necessarily be involved unless it had come to some sort of arrangement to use SHS for its own missions. Then it would have a legitimate reason to be looped in. But NTSB would still be involved in any case as that agency has jurisdiction over investigating major non-watercraft-involved transportation-related accidents including bridge and tunnel collapses, bus and subway crashes and train derailments in addition to their much better-known work on aircraft accidents.
SpaceX would certainly need to provide answers to any questions raised by then-current or even prospective customers for SHS about any accidents involving that craft. SpaceX is a business. It can’t maintain any credibility with customers by being cagey about mishaps.
I don’t know why you went to all this trouble and wrote all these words to assure me that SpaceX would be forthcoming with the appropriate parties. I said that I thought they would in this case and probably would in the case of “Starship.” You took four paragraphs to school me and show your fan boy colors because you seemed to think that I was criticizing your sacred company. I was merely pointing out to Jeff that they did owe a complete and thorough explanation to the government stakeholders while not owing one to the public in general. Now that I have explained myself to you, I would suggest that you save your criticism for Robert.
I did it because the tone of your comment was, in essence, that SpaceX can’t get away with hiding anything from the government this time but they might in future. That just seemed uncalled for. SpaceX is not “sacred,” it’s just much-maligned for no good reason. Especially as the only Commercial Crew participant with a demonstrated corporate history of cover-ups and even criminal activity is Boeing. If Eric Berger at Ars Technica hadn’t done his digging, would we even know about Boeing’s own failed abort system test of June 2018? I don’t think so.
The tone and substance of my comment was that SpaceX did not owe an explanation to anyone other than the stakeholders and I was sure that they either already had the data and conclusions or that it would be shared with them in a timely manner. I did wonder out loud if they would be as forthcoming when there were no stakeholders but I stated that they would probably do so. You misconstrued what I said and chose to color it. If you wish to double down on your impression and claim it to be fact in the face of my clarification, put up your fanboy flag and have at it. If not, just accept that I was not taking a shot at SpaceX and you misinterpreted what I said. Stuff happens. No hard feelings.
NASA should certainly get one but if they were intimately involved in every aspect of the investigation and testing process, they may have the information already. I’m figuring that NASA, the FAA, the NSB and the USAF all have received very detailed copies of the report.
All of those agencies have no doubt been given all the gory, engineering, details involved in the investigation.
As I’ve previously noted, probably not USAF and FAA, just NASA and NTSB.
I think you are correct.. SpaceX though does like to hide things
What do you imagine SpaceX has hidden? The company has been positively chatty compared to, say, Boeing, that didn’t say a word about its own Starliner test misadventure until a journalist ran a story about it.
thats not true…Boeing was fairly open about its thruster issue…
SpaceX turns off the camera everytime there is a hint of failure…they have spent three months saying nothing about the blow up and the information out there now is semi propaganda…there is little technical information
No it wasn’t.
The first Space News story on the problem was datelined July 22, 2018. The story was very light on details. For example, there was no date given for the actual test other than “June.” The Boeing spokesman quoted in Space News had nothing to say about the cause of the accident other than that “we are confident we found the cause and are moving forward with corrective action.” Talk about propaganda!
Another quote from the Space News story by the author – “Boeing didn’t issue the statement until after the first published report about the anomaly by Ars Technica.” The Ars Technica story had appeared only a day earlier on July 21, 2018.
SpaceX acknowledged the D2 explosion at the time it occured, not a month or more later. Just as previously, with Amos-6, it had little to say afterward pending the results of its investigation. SpaceX, given that it is only a self-described 80% of the way through said investigation, would likely have held off public comment for another two or three weeks had not NASA Administrator Bridenstine chided them for their silence for some reason a few days ago. In the case of Amos-6, the public explanation came only after SpaceX was done investigating and making preparations to return F9 to flight.
Compared to Boeing’s mingy statement about its Starliner test problem, the SpaceX announcement about D2 two days ago was filled with technical information.
If it wasn’t for double standards I guess you’d have no standards at all.
SpaceX had no ability to not acknowledge the explosion, it was obvious. Boeing released information as fast as they had information to release.
these technical things take time. It is like I was always telling reporters at airplane crash sites, “it takes time”
Pretty obviously not, given that Boeing had nothing to say until a journalist smoked them out. The statement at that time simply acknowledged the problem and attributed it to some “resonance” issue. I seriously doubt that that information came into Boeing’s hands only moments before its release.
Since Boeing did have the ability to not acknowledge its problem, it choose to keep it hidden from general view. Just what one would expect from the same gang of idiots running the show at Boeing these days who also decided to be cagey about 737 MAX’s handling peculiarities anent its predecessors until that particular cover-up also became untenable.
This culture of dim-witted criminality has been going on at Boeing for at least two decades if the evidence uncovered during the so-called “tanker scandal” of the early 2000’s is any indication.
And I want to spend a weekend of erotic abandon with Carmen Electra in a Vegas penthouse.
If you can find me an instance of such a detailed document ever being made public about any prior space mishap – even those involving actual fatalities – please don’t fail to inform us all.
To be fair, both the Challenger disaster and Columbia disaster causes have been documented in excruciating detail. But the space shuttle orbiters were originally built for NASA, so they own the vehicle designs. So there was no issue with publishing papers including exactly how the SRB field joints were designed and how the RCC panels were attached to the orbiter’s wings.
One of the downsides of commercial crew is that such detailed information will necessarily be harder for the public to obtain since it is all considered proprietary. The companies who own the designs will decide just how much information will be released.
I’ve never looked into how much info was actually released post-Challenger and post-Columbia, or even post-Apollo 1. I’ll take your word for it. Certainly, the general gist of what happened in all three cases was publicly disclosed rather quickly. That has been true, if not quite so quickly, of all three SpaceX accidents. The no-doubt voluminous details of SpaceX’s accident investigations have been, and will, be made available to the affected government agencies, of course. But it’s not obvious that any compelling public interest would be served by doing likewise for a general audience, especially given ITAR, not just commercial confidentiality, concerns.
a great deal …the entire affiars were conducted pretty much in the open…
that should have happened here. there is nothing proprietary when the US government is paying all the money
But the government isn’t paying all the money. SpaceX has some of its own money invested in D2, just as was required for Dragon 1. The government is paying an appreciably greater amount of money to Boeing for Starliner with Boeing putting little if anything into the pot alongside. Yet Boeing didn’t even publicly acknowledge any problem with the June 2018 abort system test until smoked out by a journalist. Hypocrisy, thy name is Oler.
the program would not be happening without US gov money, the SpaceX and Boeing contribution is lite.
That the program would not be happening absent government funding is both obvious and irrelevant to the immediate issue. The Boeing contribution to its CC efforts is pretty nearly non-existent. The SpaceX contribution is much larger.
there is nothing detailed about this…its a “simple explanation” full of rhetoric “the super D survived showing how tough they are” LOL
see how it works out. but clearly they must have tested the entire plumbing system on some sort of mockup so they found something new here
anyway back in Houston so I’ll get more stuff from my friends…
It’s not detailed in an engineering sense, but the explanation that SpaceX has just provided anent the D2 explosion is still a lot more detailed than what Boeing has ever had to say officially about whatever it was that happened to Starliner during that abort system test over a year ago.
Maybe you could ask your “friends” at both NASA and Boeing about that while you’re at it. What happened to Starliner? The world wonders.
not true…and the SpaceX explanation is about like their launch vehicle reusability…vague at the current rate of “reuse” the USAF now thinks it will take them about a year of prep to get the 10th reuse…which will never come 🙂
Not sure exactly how to interpret your remark.
Is it the opinion of “USAF” that it will take a year for a single Block 5 F9 to chalk up 10 flights? I’d be inclined to agree with that given the limited availability of launch slots and the fact that SpaceX is going to have to slot Starlink missions – which looks to be SpaceX’s chosen medium with which to pioneer reuse milestones – into its already busy schedule of customer missions at facilities with a fairly modest upper limit, as yet, on total annual launch ops.
Or is it the case that “USAF” thinks it will take an entire year to put a notional 9-times-reused Block 5 booster into shape to attempt a 10th go-around? If that’s the case, I think SpaceX will be able to allay “USAF’s” concerns within a year just based on Starlink deployment missions.
its the opinion of a group of “rocket scientist” inside the USAF that if they ever get to the 10th reflight, it will take over a year to get the booster ready. predictions are they will not get over 4 or 5 reflights in a multi year period. in other words SpaceX has reinvented the shuttle
Well, as I say, I don’t think it’s likely to take more than a year to prove your USAF “rocket scientists” correct or incorrect. I think it will be the latter. F9 Block 5’s are already turning around faster than was the case with all but a handful of Shuttle missions.
Yet they aren’t getting any faster. They seem to be stick at 76 days as a minimum turn around time. And it’s disingenuous to claim that that time is still driven by external factors. They’ve had several opportunities now to take a recently flown booster and turn it around quicker. But yet, they haven’t.
Wrong again. Keep repeating dubious claim, keep getting called out for it.
Not wrong. No F9B5 has reflown sooner than 76 days. Musk is the one who has touted fast turnaround times. But they haven’t happened, despite several opportunities to do so. If SX could turn one around faster, why the heck wouldn’t they? That would prove that they could do what Musk has been claiming they can do. The reason appears to be “they can’t”.
But I’m not worried. We’ll see how fast they turn around the StarLink boosters. My guess is not much faster. I doubt it ever gets below 50 days.
Don’t get me wrong. I’ve been hoping all along SX could turn them around in a week to 10 days, which would be amazing. But unlike fanbois like you, my opinions are ruled by data, not emotional arguments and “hopes”. The current data shows that 76 days is the present lower limit.
“If SX could turn one around faster, why the heck wouldn’t they?”
Because there is a 1000 other factors besides booster availability that governs the launch cadence.
Will you still be using that excuse if they aren’t turning them around any faster in, say, a year?
Yes, because It isn’t an excuse. You are using the wrong number (because it is the only one you have) to measure effectiveness of reuse. If you show me evidence that launch manifest is booster turn-around constrained then I will re-evaluate.
I will give you another tidbit to show how many other factors are in play. The new S2 test stand is almost complete and designed around increasing cadence of S2s out of McGregor while not blocking the M1D and MVac stands. Lots of things in the flow have to be optimized to increase flight rate, irrespective of booster reuse, not the least of which is cooperative payloads and range schedules. So you can continue diluting yourself with a single data-point of little value or open your eyes, your choice.
Cooperative payloads and range schedules could have been managed to turn things around faster, at least once. Are you therefore admitting that Musk’s claim of 24 hour turn around by sometime this year is a fantasy?
Not a fantasy but certainly a stretch goal (like all of his are). The payloads will be less of an issue because they will be all Starlink and SpaceX has been working with the range for years to streamline process, including AFTS and many many other process improvements. The demo would obviously require the payload, range, GSE, weather all cooperate. That has nothing to do with booster reuse.
Again, you are missing the entire point of 24 hour turn, it isn’t exercise other than in a demo, they can be parked for weeks, it’s for minimal touch labor.
https://zlsadesign.com/post…
“The Block 5 Falcon rocket that we’re rolling out later this year is going to have, uh, reusable thermal protection on it; so we don’t burn up the heat shielding on it. And it’s going to have a much better landing legs that just fold up and; just drop the rocket, fold the legs, ship it, fold the legs out when it lands. Making it turn very fast; our goal is; Elon asked us to do a twelve-hour turn. And we came back and said without some major redesigns to the rocket, with just the Block 5, we can get to a 24-hour turn, and he accepted that. A 24-hour turn time. And that doesn’t mean we want to fly the rocket, you know, once a day; although we could, if we really pushed it. What it does is, limits how much labor, how much [touch?] labor we can put into it. If we can turn a rocket in 24 hours with just a few people, you’re nuts. [inaudible] low cost, low opportunity cost in getting the rocket to fly again.”
I think we’re talking past each other a bit. Musk came up with 24 hours. I’d be happy with 15-20 days. My point here is that since the beginning of the year, there have been two or three opportunities to fly a previously flown booster in less that 76 days. If it really takes less time than that to refurb one, and the upcoming payload was going to use a refurb, why not use it?
As you say, Starlink is likely to be the proof of all these puddings. The coming year will be interesting.
For customer launches, the customer also has to agree. I’m guessing it will be Starlink deployment launches where SpaceX will progressively demonstrate both greater-than-three-times reusability as well as additional cuts in turnaround time.
Clearly the customer had already agreed, since in the cases I’m talking about, the second launch used a refurb booster. Try again. 🙂
Anent launches on refurbed boosters, it is my understanding that the customer can indicate a preference among the inventory of flight-proven hardware. NASA is known to prefer lightly-used-once boosters for CRS missions. USAF dipped its toe into the reusability waters with the pair of lightly-used Block 5 FH side boosters from the previous FH mission.
I think SpaceX will push the envelopes for both number of uses and turnaround times on upcoming Starlink deployment missions. Over the next year or so, we should see significant increases in the former and decreases in the latter. Once customers are comfortable that SpaceX has proved out these envelope expansions with its own missions, we’ll begin to see third-party missions following suit.
You, obviously, don’t agree. That being the case, I’m not going to waste further effort attempting to convince you, we will simply have to await the verdict of time and events.
Anent launches on refurbed boosters, it is my understanding that the
customer can indicate a preference among the inventory of flight-proven
hardware.
Can you cite some reference for this statement? Other than, you know, things you read on blogs?
Yup. They will very likely fly this year, and might still beat Boeing.
Given the time ULA needs to turn SLC-41 around after the AEHF-5 mission, now scheduled for Aug. 8, and the fact that the first Starliner mission schedule is also to include at least one wet dress rehearsal – a step ULA doesn’t usually do with its Atlas V missions – that unmanned Starliner test can’t take place before the end of the third week in Sept. at the very earliest. It could easily slip into early Oct. If that happens, Starliner’s first manned mission is virtually certain to be delayed until Jan. 2020 or later. Even SpaceX will be hard-pressed to make the now-notional Nov. 15 launch date for DM-2, though it still seems to have a more than decent shot at beating Boeing to ISS with people given what we now know about the probable cause of the April 20 D2 accident and what needs to be done to prevent any repetition of same.
Glad it’s not a showstopper of a problem. But I doubt it will fly this year, my gut says February.
Funny, my gut says Dec. this year. I guess we’ll have to suit up in sumo gear and battle gut-to-gut. 🙂
The FAA needs to look into the effects of high pressure nitrogen tetroxide (NTO) on titanium. It also needs to review the rules on valves – there are too many other problems with valves.
The FAA has no jurisdiction over spacecraft engineering, just aircraft. The agency must issue licenses for launches and re-entries because it also regulates airspace use over the U.S.
The weak jurisdiction does not matter. The same rules will apply to titanium and titanium valves in aircraft. Doubly so since the Dragon 2 blow up on the ground.
There are no aircraft with hypergolic reaction control systems or any other system that uses a liquid oxidizer. You’re being ridiculous. The FAA has no basis for being involved in the D2 investigation or in issuing any “rules” it has no authority to enforce.
the USAF will get the report as will the FAA…
As a courtesy, the USAF almost certainly will. SpaceX has good reason to hand over a copy to USAF even without being prompted, despite USAF having no consequential interest in D2, per se. It could certainly be argued that USAF insight into the D2 investigation would serve to further familiarize USAF personnel with SpaceX engineering and investigative practices and build confidence in SpaceX’s suitability as a supplier going forward thereby aiding in future vehicle certification efforts. Most likely, USAF already has access to a lot of such info already if one assumes it was the actual owner of the hyper-secret Zuma payload that was lost. In any event, I certainly don’t foresee any effort on SpaceX’s part to keep the investigation of the D2 explosion secret from USAF if that organization expresses interest.
The relevance of any such request by the FAA is a lot more problematic as both the accident and investigation are entirely outside the FAA’s wheelhouse.
both the USAF and FAA will get full access. you dont know how this works…
You may well be right, but not because either USAF or FAA have any actual say about D2.
For reasons of its own that I already explained in a previous comment, SpaceX is likely more than willing to keep USAF in the loop on everything.
It’s a bit harder to see any basis for their wanting to do likewise anent FAA. That isn’t to say there may not be those within FAA who might be inclined to want to be read in for bragging rights if nothing else and would not be above making some implied threats anent future SpaceX launch licensing to get their way. I do know how these things work, especially since the Obama administration, when government agencies were pretty much encouraged to run amok and expand their mandates well beyond what was allowed to them by statute.
You mean currently there are no aircraft …
The Dragon 2’s main thrusters are used in the lower atmosphere for emergency escape during launch and to control landings. That is when the spacecraft is acting as as aircraft.
This definitions problem is similar to the old conundrum is a hovercraft a boat or an aircraft?
That doesn’t change the fact that FAA’s only involvement in spacecraft is anent their launch and re-entry through U.S. airspace. FAA has no role in vetting spacecraft engineering, safety or “spaceworthiness.” Nor should it, as it has zero institutional knowledge about any of these matters.
The FAA issues launch vehicles and reentry vehicles with safety approvals under regulation 414. The main use of the Dracos is in the atmosphere during launch and reentry. A capsule blowing up can destroy property.
An exploding booster would be even more likely to do so if there were any property near enough to sustain damage. Which is why launches don’t generally fly over, or within shrapnel range, of much of anything.
And that still doesn’t give FAA any veto over matters of spacecraft engineering. FAA issues launch licenses based on worst-case scenarios not resulting in any consequential damage to third parties. It doesn’t get to kibitz about things that may or may not cause such worst-case outcomes.
In this life everything gets regulated. NASA is not a regulatory agency. So the FAA (or replacement) will regulate escape systems. Laws change.
To judge by the 737 MAX debacle, the FAA seems to have its hands more than full regulating aircraft engineering. Spacecraft engineering may – someday – be subject to regulation, but not soon and not likely by FAA. In the meantime, FAA has no statutory authority to say boo about anything related to spacecraft except their launch and re-entry profiles and timings.
Laws do change. But not invariably in the direction of more centralized control. Unlike the prior administration, this one is not looking to tighten the regulatory screws. Quite the opposite in fact.
Well, it’s great to get some news.
I kept imaging that the oxidizer and propellant had to come in contact somehow, somewhere outside the combustion chamber. This would have occurred during pressurization (whilst being shaken, not stirred). Couldn’t quite imagine how both of the fluids would get free and in contact aside from a bolt or bracket or somesuch coming loose in the the shaking and acting like a ricocheting bullet amongst the plumbing. Or, if a bracket failure (possibly weakened by corrosion due to saltwater immersion), maybe a now-unsupported pipe breaking free and acting like a swinging cudgel during the shaking. Still, the problem occurred upon pressurization (which Hans previously said initiated properly), which would seem to implicate a valve or leaking/structural failure of a line or tank — but again, how did both the oxidizer and the propellant get out…
Now we know. It was just the oxidizer alone reacting with the valve material itself, and a small leaked “slug” of the oxidizer itself acted as the bullet/cudgel by being accelerated into the next valve down the line due to the sudden (but normal) pressurization of the system. Fascinating
Oxidizers can be very nasty stuff. For example, LOX spilled on asphalt creates a contact explosive. So everything underneath any LOX tank, plumbing, launch vehicle, and etc. needs to be concrete. Cite:
https://sciencing.com/spill…
This is a serious design flaw. That pressurised system should never leak unless there is already a catastrophic failure of the vehicle and the occupants are already dead. Should this problem have been foreseen? If the answer is to that simple question is “yes”, then, SpaceX has a much bigger problem. As I have mentioned before, Dragon II should be the safest capsule ever built, because all the others rely upon shutes alone to return the crew safely to the Earth’s surface (single point of failure). Dragon II, on the other hand, with it’s Super Draco thrusters and suitable avionics, would have the option to slow the vehicle retro-propulsively, in the event of a normal descent shute deployment failure. That pressurisation system should be designed and built to be effectively “bullet-proof” and shown to be so by a test capsule being repeatedly “dropped” and the system pressure tested.
Serious, but also found. The reason for valves, as opposed to burst disks, in the first place was because the original idea was that the launch abort engines would mainly be used for landings, not aborts, and that they would be subject to a short initial burn high up during descent to verify correct function. Thus, on a typical mission, the big thrusters would need to light twice. Given that powered landings are now off the table, they only need to light once so a one-time-only solution is acceptable by way of replacement.
As for post-modification testing, that seems to be a complete no-brainer so your implied concern this might not happen seems entirely misplaced.
Sure he’s a mannequin! I believe it, just that the research would be so much more valuable if it were a real breathing human? Because we don’t see him move, and why the need for the helmet on a mannequin? I’m sure it’s just my imagination running wild, but a “kidnapped murderer”/Death row inmate/inmate suicide? So many people go missing daily that there’s no way kidnapped, murdered, runaways, plain old lost people or you name it can account for all of them. Where are they going? Alien Abduction? Demons? Secret Government testing? And so on, I know it sounds like malarkey mixed with a dose of conspiracy, though the simple fact of the matter is that it just can’t be explained to where all these missing people have gone? Question Mark after Question Mark! By the way, yes they have questioned Mark! I’d like to hear what anyone else thinks about this? How do the people that have rational (think they) explanations for every happenstance in this crazy place called Earth that we call Home?
Yeah, see, there’s these things called human subject research protocols. Putting people on the first launch of a new spacecraft is not generally within such protocols, though NASA has, admittedly, done so at least once.
The helmet – and the whole spacesuit for that matter – were on the dummy to gather information about the suit’s interaction with its wearer. These dummies are lousy with sensors of various kinds. It would certainly be good to know that a helmet isn’t going to cripple its wearer under the G-forces and vibrations of a space mission ascent, for example.
Why do so many people disappear? You seem to assume that such disappearances must be involuntary in all cases. In most cases, I suspect otherwise. People have been disappearing without prior notice since there have been people. Most such absences are voluntary and self-engineered. In the 19th century, many such instances involved people dissatisfied with life where they were who simply decamped without ceremony or notice for a potentially better life in some distant place. There was a saying at the time that such people had “lit a shuck” – meaning departed at night using a lit corn shuck torch to light their way – or “gone to Texas.” According to your own taxonomy, these people, regardless of age, and now as well as then, are “runaways.”
Can we pay you to be the next test pilot?
NASA is already paying two people to be the next test pilots of D2. They both look pretty fit so I don’t much fancy the chances of anyone looking to try taking their rides away if the argument turns physical.
This reminds me of the Rhutan Nitros Oxide explosion. The manufacturer of this gas has a safety bulletin out about it talks about valves. etc. I put it up several years ago. But SpaceX must not read comments from the public. Spacex can not use imagination to transfer one accident to something that might happen to them. I guess they read and decided it did not apply to what they were doing.
Nitrous oxide (NO2) is known to be capable of auto-deflagration. The D2 accident did not involve nitrous oxide, it involved nitrogen tetroxide (N2O4), a different chemical. And the accident was not the result of auto-deflagration, it was the result of actual combustion with a second substance, in this case titanium. The Scaled Composites accident of a dozen years ago has no relevance to the D2 explosion. So no, it did not apply to anything SpaceX was doing, but for reasons having nothing to do with any lack of due diligence on SpaceX’s part.
Rutan’s name, by the way, has no “h” in it. Perhaps, given the eccentricity and randomness of your mental processes, you confused his name with that of the small Asian nation of Bhutan?