Ah, it *is* rocket science.
Too bad. Try again.
Elon Musk's Falcon 9 rocket exploded after liftoff today over the blue skies of Cape Canaveral, Florida – the catastrophic failure happened within minutes of the launch. The unmanned SpaceX rocket was carrying the Dragon capsule on its seventh planned mission to the International Space Station. The pod had been loaded with …
"something was expecting standard US units of inches per day"
No, it's changed, the standard is now furlongs per fortnight. It's much more poetic.
Currency exchange rates from www.timegenie.com on 2014-04-02
2866 units, 109 prefixes, 79 nonlinear units
You have: 1 inch/day
You want: furlong/fortnight
One of the units supported by a liquid flow controller for which I wrote the firmware was acre-feet per fortnight. OK, though it rolls of the tongue in a lovely manner, it didn't make much sense for the size of the controller and the industry for which it was targetted. But that unit actually does make sense to somebody managing a reservoir.
A tweet from Elon Musk suggested it was an over-pressure event in the second stage oxygen tank. So probably something like tank burst causing debris which took out the first stage.
At the press conference that has just finished Gwen Shotwell of SPaceX said she wasn't aware of the range safety being used. There were also comments that telemetry from the Dragon carried on after the event.
The tank stirring likely saved the Apollo 13 crew: the tanks needed regular stirs (else wouldn't have had stirrers fitted) but on a slower schedule. However the tank sensors were giving bogus readings so NASA had them do additional stirs in the hopes of getting sane readings. If the insulation sparking had occurred with the normal stirring schedule then the spacecraft would have been entering lunar orbit when the explosion occurred, meaning that it would need the service module's rocket engine to get them back to Earth. And that engine was damaged in the explosion...
So stir, Swigert, stir! :-)
"So probably something like tank burst causing debris which took out the first stage."
Another possibility is that rockets tend to depend on pressurization for some of their structural strength, if not all to the degree of the Atlas series of rockets. Poke a big hole in one of the pressurized tanks and the stack will buckle. My money is max Q rattled something loose, the tank burst, and the upper stage collapsed when the tank depressurized. There was a lot of liquid oxygen spilling around the rocket in the last seconds.
Anyway, first person experience with the launch:
I was visiting relatives and got to see the launch with mark one eyeballs. A lot of folks turned out to watch it, but headed in when it got faint - the conditions weren't great for a continuous contrail so it got hard to see near the failure. They didn't find out until half an hour or so later when news started circulating.
I stuck it out (partly because a tree had hidden the first part of the launch and I wanted to see more) and got to see the *poof* at the end, which didn't look like normal staging. I was checking to see what happened on the webcast when the original launch noise reached the house, which was an odd bit of sonic time warp: I was hearing the initial launch noise of a ship that had already blown up.
That is also my (nearly useless) perspective of the video. Musk's comment agrees.
Still, even if that is the proximate cause, the root cause could be different. Columbia broke up because a wing failed. The real problem was the inability of management to address a known, manifest flaw in the design of the external tank insulation.
pretty danged rare
Not at all. Rather regulary:
Lightning regularly strikes airplanes. In fact, as far as anyone knows, the odds are that each airliner in the USA will be hit by lightning once a year. (Obviously some would be hit more than once, some not at all.)
Saw one get hit on the approach once. For some reason this created a weirdly greenish light IIRC.
"Also, i blame Microsoft. natch ;)"
Auxilliary Navigation Cluster: Oi, boss, you heard what they were loading into the Orbital vehicle earlier?
Master Logic Unit: Concentrate please, Nav, we're not long past max Q and I'd rather you kept your circuits on the job.
Auxilliary Navigation Cluster: But the OVC said it saw the lads securing some Microsoft kit on board!
Master Logic Unit: Please tell me you're shitting me. Orbital, is this true?
Orbital vehicle Control: Afraid so boss. Saw the dodgy logo on the boxes as they came aboard.
Master Logic Unit: Oh FFS, what were they thinking? There's no way I'm letting any of that crap into orbit, do they think we have no self respect? Oh well, I'm afraid it's anomaly time chaps. Been a pleasure and all that. Flight abort XX99, override authority code G33W1ZZ, initiating master self destruct sequence in 5,4,3...
...everyone else who has tried didn't have many, many failures in the early stages of development. Admittedly SpaceX are standing on the shoulders of giants, but they are still doing new stuff so unexpected and violent disassemblies are to be expected, sad though it is. It really is a shame because I was really looking forward to better if not perfect stage one landing this time. That's a "proper" rocket!
Now they need to find out why they got an over pressure, mitigate against it happening again and make sure there's a pressure valve capable of handling it if it does happen again.
"Now they need to find out why they got an over pressure, mitigate against it happening again and make sure there's a pressure valve capable of handling it if it does happen again."
This is why rocket science remains rocket science. When you are treading on such thin ice as a multistage rocket launch,it isn't just a case of venting overpressure but of eliminating it in the first place. That oxygen is needed to power the rocket...
It's deeper than that. The failure is not just a component failure or a bad design; it is a failure of an engineering/manufacturing process to notice a bad component or bad design.
Something they were awfully sure about turned out not to be true. They should be asking what made them so sure, why they were wrong, and what other things this suggests they are overconfident about.
One goes to Fox, NYT, and others for this news and the comments are filled with BS about Obama did it, ISIS did it, you're polluting the air and ocean...yada..yada.. yada... Have one on me fellow commentards... Nice to see intelligent commentary that doesn't degrade into garbage.
"drags them and anyone who will listen pretty far from reality."
Facebook, targeted ads...you see what it thinks you wants to see and the more you see it, the more it thinks you want to see it. Zuckerberg isn't just a danger to democracy because of his relentless spying on people, but because Facebook causes people to see nothing but a mirror of their prejudices.
It's nice to be above average, then. I have never watched Fox "news", and even CNN has shifted over to more talking heads than hard news. I get mine from BBC.
We're not all idiots over here in the colonies, but you could be forgiven for thinking so, if all you go by is our "news" media.
According to a radio 4 prog I was listening to while driving up the A1 in the wee small hours of last monday morning It's already been done. In Chicago using hydroponics. (The USian factory vegggie farmer called it by a different name so it appears that we have another difference between English and American.)
He and the BEEB were enthusing about not wasting good land for growing food and the factory farm being right by the point of consumption, and saving space by growing veg in multiple levels.
Beeb were particularly taken with LEDs being used for the lighting.
Mind was 90 per cent on the road, 10 percent on the proggy But ISTR that it was in some disused disco building or something.
Off topic - or maybe not if your tin hat is tingling.
Have to agree with everyone else here, these missions haven't been a failure because without the Falcon 9 (despite it being unsuccessful so far at landing) the 1st stage is designed to be disposable. The gutting part of this is that it happened before separation.
Each time they reach separation, they're doing no worse than before the Falcon 9 and when they do finally get it to land successfully, they'll have started saving money compared to previous 1st stage launchers.
Even now when I watch the videos of the attempted landing of the first two, despite knowing what happens, I still find myself willing that little thruster at the top to hold it upright before it finally gives out and tips over.
Try balancing a pencil upright on your fingertip, now imagine trying to do that using thrusters and a pencil the size of a rocket. The fact they've come so close is quite honestly astounding.
Chin up guys, you're doing great work, get to the pub, drink it off and try again.
Try balancing a pencil upright on your fingertip, now imagine trying to do that using thrusters and a pencil the size of a rocket.
1) Create a mathematical model of your system
2) Design, test and tune the cybernetic control mechanism (Thank you, Norbert Wiener, Claude Shannon, John von Neumann etc. etc.)
4) Look ma, no hands!
3) Compensate for random atmospheric conditions and reducing speed from terminal velocity.
Thanks for the links guys, got my Monday morning reading material (well perhaps Monday afternoon, it might require some thought to understand it). I have to admit I didn't consider broom handles are easier.
Does anyone remember the story from the golden age of science fiction wherein the planet was being vacated at the rate of thousands of rockets a time, and the narrator was praying that he was not on one of the tiny percentage which would explode?
I guess this will never change.
They say there are no atheists in a foxhole: I'll bet there are about as many Musk fanboiz on the space station
Well, it is after all the first failed launch ... out of 19. The Russian garbage used by competitors has a higher failure rate, which means that the ISS crew are probably still rooting for SpaceX's engines.
At the moment every stage that goes up is lost; if it works great. If not then the hope is that details analysis of the telemetry and design and provide a definitive cause, but I imagine that often leaves gaps in their knowledge.
However what will soon be revolutionary (beyond simple reuse/money saving of course) for SpaceX and the Falcon is that they will be getting their first stage BACK. That means that can then tear the thing down and see what held up well, what broke (but did not result in a critical failure) and what was stressed near it's limits. Once they have that I image that rocket reliability will jump well ahead of anything else.
Also keep in mind much of the Falcon 9 Stage 1 hardware/tech is present (or will be) in their other stages, so lessons learnt there can be applied elsewhere.
Space shuttle and Delta Clipper already did reuse. From what's been studied and said the hard part isn't getting it back, it's making it ready to fly again for notably less than making a new one.
If the tanks rip open after 3 launchers, there might be economic challenges.
...that the only way the pressure could rise in the oxygen tank is if
1) More oxygen were added
2) The oxygen warmed up
3) The tank got smaller
The first is not possible. The second seems unlikely; a fire near oxygen normally would result in some sort of explosion, not a gentle warming up. An explosion would have destroyed everything, yet the first stage was clearly still operating after the first stage had got into difficulties. So it might have to be the third.
That implies that there was a structural failure of the upper stage resulting in the oxygen tank crumpling up as the stage collapsed lengthwise.
If it is a structural collapse, that's pretty bad. That's the most basic and easiest part of rocket science. It would be most unfortunate if this were indeed the cause of the failure. Some panel falling off from higher up could result in a puncture, which I suppose might weaken the stage structure. There did appear to be quite a lot of gas streaming off the upper stages during the ascent.
As Mark85 quoted, "The rocket science is the easy part, the doing is the hard part.". A launch failure due to a structural failure obviously won't help convince any future astronaut that it has been built right, never mind designed right. Safe flight operations is largely about having the right process and sticking to it; SpaceX's process clearly still has some flaws which need to ironed out.
As the great Feynman said:
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled."
I'm hoping that Elon Musk has that put up on a large poster opposite his desk in his office, and everyone else's too. NASA were serially guilty of putting PR first, and it cost Astronauts' lives.
Anyway, I'm sure they'll find the problem and get it ironed out. I hope so. If there's one good thing to come out of this, it should be the question, "What else have we missed?".
"It looked like a fault triggered a self-destruction/abort, was a very neat explosion"
I think SpaceX has stated range safety systems were not engaged, but the reference is eluding me. What I'm finding now are saying, "It's not clear if range safety systems were engaged."
Also, that wasn't an explosion in the sense of having combustion in the fumes. Most of the cloud and "fire"works were from the supercold vapor cloud, similar to the Challenger break up.
As pointed out above, it seems* more likely that the problem was a loss of pressure, because the fuel tanks contribute to the structural integrity of the vehicle (which, for obvious reasons, needs to be as light as possible). The commentary states that it had just passed through max-Q (the point of maximum dynamic pressure, which rises as speed increases but reduces with altitude), so any weakness would have been revealed at that point. But I'm sure the investigation will tell us.
* Disclaimer: I am not a rocket scientist.
"As pointed out above, it seems* more likely that the problem was a loss of pressure"
Elon Musk tweeted that, "There was an overpressure event in the upper stage liquid oxygen tank. Data suggests counterintuitive cause".
I'm presuming that if there had been a puncture and loss of oxygen or something else that provided pressurised structural integrity he would have tweeted accordingly, but he didn't.
We'll see what the counterintuitive cause is thought to be sooner or later.
The upper stage tanks tend to have a bladder to help push the reactants to the pipes so the engine can run, they don't like to stay put in the absence of gravity. These bladders are filled with helium as it's neutral and won't freeze. If the helium is supplied at the wrong time and rather excessive pressure though...
"NASA were serially guilty of putting PR first, and it cost Astronauts' lives."
Often quoted as fact, but actually wrong. Yes, Feynman got it wrong. He was a good physicist. That doesn't make him a good investigator of organizational problems.
Description of Normalization of Deviance
"Social normalization of deviance means that people within the organization become so much accustomed to a deviant behavior that they don't consider it as deviant, despite the fact that they far exceed their own rules for the elementary safety". People grow more accustom to the deviant behavior the more it occurs . To people outside of the organization, the activities seem deviant; however, people within the organization do not recognize the deviance because it is seem as a normal occurrence. In hindsight, people within the organization realize that their seemingly normal behavior was deviant.
The Challenger Launch Decision
Diane Vaughan developed her theory of the normalization of deviance in The Challenger Launch Decision. She details how, during the developmental phase of the Space Shuttle Program, the normalization of deviance resulted in a dangerous design flaw in the design of the spacecraft. The group that was assessing the joints on the solid rocket boosters conducted analysis to find the "limits and capabilities of joint performance. Each time, evidence initially interpreted as a deviation from expected performance was reinterpreted as within the bounds of acceptable risk". The acceptance of this risk led to the Challenger exploding on the morning of January 28, 1986.
Morton-Thiokol was contracted by NASA to manufacture the Solid Rocket Boosters (SRB) that were used in the Space Shuttle Program. In 1981, a problem with the putty that was used to seal the O-rings on the SRBs was discovered. When the putty was added to the boosters, bubbles formed. During take-off, the gases from inside of the SRB would go through the bubbles resulting in a "localized high temperature jet which was drilling a hole right into the O-ring". Morton-Thiokol changed the putty and the method of putty application and considered it fixed. The engineers knew that the putty erosion could still occur, but with a very low probability of a catastrophic disaster. NASA determined that the erosion of the putty was an acceptable risk of flight. NASA and Morton-Thiokol characterized the erosion as an anomaly that was to be expected since the SRBs were such a new technology. Subsequent test flights showed putty erosion that was deemed acceptable by NASA and Morton-Thiokol even though the joint actually "deviated from expected performance".
NASA and Morton-Thiokol suffered from the normalization of deviance when assessing the safety of the SRBs. Diane Vaughan states, "As [NASA and Morton-Thiokol] recurrently observed the problem with no consequence they got to the point that flying with the flaw was normal and acceptable". On January 28, 1986, the normalization of deviance within the two organizations contributed to the loss of the Space Shuttle Challenger and the seven astronauts on board.
Slight problem with the above analysis. Oxygen boils off the whole time and is vented. The only period when it isn't is then they close the vents for a short time a few minutes prior to launch. This pressurises the tank to give the rocket more rigidity. Like the tubes in an inflatable dinghy. But then the vents open again to prevent the pressure building up too much. These things are a bit more complex than a pressure-cooker safety valve. They have remote control, they have to work OK with ice in them, and they have to work in a supersonic airflow. The rocket is being warmed by the sun the whole time, which will cause some boil off. If they close for some reason, then Kablooey. Hopefully the guy who said it was all normal did not have all the information. I hope there were people at SpaceX staring at their screens and going "Ohhhh Crap" for a few seconds before it went bang. That would be good, because this is going to be a manned rocket soon. You want some warning of this type of event when there are people riding it, so that the escape system can do it's thing.
I grew up with the space program, and watched most of the Mercury, Gemini, and Apollo launches as a child or young teenager. It was all quite exciting, even given the reliability of those programs (Trivia: All of the Saturn V launches were not considered successes, despite reaching orbit.).
For those that care to remember or do the research, Apollo 12 experienced a lightning strike 6.5 seconds into the launch, with the electromagnetic pulse caused by the lightning resulted in the fuel cells going off-line (due to false overload sensing), resulting in the batteries being overloaded, which shut down most of the Command and Service Module, and this triggered just about every warning light in the craft. Fortunately, the first stage Instrument Unit ring remained functional, and kept the rocket flying in the desired attitude (else the thing may have went sideways and broken apart).
It seems that no one had anticipated that a rocket going up towards the clouds, with that long plume of hot, ionized gas behind it, would make for a very effective lightning discharge probe. Whoopsie. As a result of this, new rules were instituted which prevents any launch if there is lightning within a certain distance of the pad (20 miles?). Additionally, NASA installed an array of Field Mills around the launch site to monitor the atmospheric electric field potential, and, if the electric field is above a certain threshold, launches are prohibited.
Obviously, those won't prevent 100 percent of lightning strikes, but they have severely reduced the number of strikes. One can only hope that the metallic outer skin of the vehicle will adequately function as a Faraday Shield, and keep the lightning surge away from the interior components.
As for Jack Swigert, he was only acting on orders to stir the Oxygen tank. And, yes, there had been some stunts involving burping the pressure, but these were unrelated to the failure, for which the root cause was a redesign of the electrical system to a higher voltage system, without the corresponding change in the insulation on the wiring in the Oxygen tank, or a replacement of the thermostat. Coupled with this was the fact that the Oxygen tank was damaged in an accident, where it was dropped, which caused some of the plumbing to be damaged. In other words, there were a whole slew of problems, each of which was relatively minor, but, which when coupled, resulted in the disaster.
As for viewing launches, I got to see Discovery launched in April of 1985 (e.g., pre-Challenger), from a vantage point about 9 miles away from the pad. After the craft had launched, and disappeared behind a cloud bank, the sound finally reached me a good 45 seconds after the launch. And, although I say "sound", it was more of a vibration which shook the ground.
Regarding the timing/speed of the craft, I have to wonder if it wasn't already past the "Max Q" point with it traveling at 1 Km/second. Still, that doesn't mean that the Max Q couldn't have cause something to shake loose or metal fatigue to fracture something. I'm sure there'll be a thorough engineering analysis to identify the failure, and then to ensure that nothing like it happens again.
As for the range safety pyrotechnics, it certainly wouldn't be easy to press that button, even for an unmanned launch (I'm told that only commissioned Air Force officers are allowed to man the range safety button. I assume that's still true, even for private launches.). I have to wonder what the effects were on the officer that pressed the range safety button for Challenger. :-(
Note that there have been Range Safety commanded actions on a number of unmanned rocket flights.
As for the "low cost" supplier, I'm told that Alan Sheppard (who I was pleased to once meet) said that his thoughts, as he was laying in the couch in the Freedom 7 capsule being launched as the first manned Project Mercury launch, were "The fact that every part of this ship was built by the lowest bidder.".
As for using LEDs to grow plants, there's been considerable research into that (And, no, not just for "grow-ops"!). It seems that plants only need about two wavelength bands of light, and that the rest of the other wavelength bands are wasted. And, if I remember correctly, there has been some consideration of genetically engineering plants to use alternate wavelengths, although I don't know that too much actual experimentation with such genetically engineered plants has been done yet (or, at least, not published) (Then, again, plant genetic engineering is outside of my field of expertise, so I haven't played close attention to that field.).
Look at 23:48 in this video https://youtu.be/ZeiBFtkrZEw (linked previously by someone else). Something cone shaped and roughly dragon capsule shaped comes falling through the initial large "explosion" cloud.
Maybe the capsule survived the initial blast on the second stage, but got destroyed in the destruction of the first stage? (Or made the plunge, didn't deploy chutes and didn't survive the hydrobraking)
NASA and the U.S. government really created a cluster by taking the space program semi-private as this most recent failure confirms. Russia and SpaceX are both unreliable sources to supply ISS.
Implying a perfect record by 100% state-owned socialistic outfits instead of the very mitigated record by pork barrel pumps supported by congressional mandates.
I think you need some .45 aspirin.
Russia and SpaceX are both unreliable sources to supply ISS.
The ULA is using RD-180 engines for their launches ... that's the stuff used for non-COTS launches. SpaceX has had only 1 launch failure out of 19 ... so I'd actually think SpaceX is actually the one with better odds.
Biting the hand that feeds IT © 1998–2020