SpaceX Moves Past Explosion With New Launch Plans (cnn.com) 75
SpaceX plans to resume launching rockets as soon as next week, after completing an investigation into a spectacular launch pad explosion that destroyed a rocket and a satellite in September. From a report on CNN: The news comes following an in-depth investigation into the explosion of a rocket from SpaceX's September mission. The company said in a statement Monday the botched launch was due to a failed pressure vessel in a liquid oxygen tank. The vessel buckled, causing liquid oxygen to accumulate. It believes this led to friction, sparks and the explosion. SpaceX conducted the investigation along with officials from NASA, the Federal Aviation Authority, the U.S. Air Force and the National Transportation Safety Board. The Federal Aviation Administration will have to sign off on the report and issue SpaceX a license to launch. SpaceX appears optimistic it will be launching rockets again soon.
Good for SpaceX (Score:4, Interesting)
I know I come across as somebody who knocks Mr. Musk, but we need more entrepreneurs like him pushing the barriers.
Re:Good for SpaceX (Score:4, Insightful)
Because nobody at ULA makes any money, and they certainly don't have taxpayer paid launches.
Might want to take a look at the dollar per payload on competing heavy lift platforms.
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One might have more sympathy for ULA once they are capable of flying without Russian engines.
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Right, so the existing military industrial complex doesn't have politicians in their pocket or gain taxpayer money either. Got it.
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I do believe that the use of Russian engines dates from an ill-guided attempt to keep newly-unemployed Russian scientists and technicians from going into the WMD business. I find it difficult to accept that ULA, having charged the US Government $1 Billion per year just for a promise to stay in business, could not maintain a non-Russian engine capability.
There's also the issue of two competitors for Federal launch, Boeing and Lockheed, forming a Trust and not being blocked from doing so.
It's pretty clear the
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Pretty sure it was these https://en.wikipedia.org/wiki/... [wikipedia.org] pulled from the warehouse to test.
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This is no longer a good argument because Russia has its own commercial launch industry now that actually beats the shit out of America's (until Musk came along). Musk got the US back into the game of commercial launch. No thanks to ULA .
Re: Musk's Deceipt (Score:2)
There's also the issue of two competitors for Federal launch, Boeing and Lockheed, forming a Trust and not being blocked from doing so.
While I applaud your anti-monopolistic inclination this wasn't a merger born out of anti competitive acquisitions or even a "we will lower prices by removing redundancy" this was a case where one Company won the contract and then it was found out that the other company had stolen designs through industrial sabotage.
The birth of ULA was the result of a very messed up and disastrous legal scandal. Effectively a shotgun wedding nobody really wanted to pave over the whole affair.
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You mean industrial espionage. And it might be that was really the only reason for forming ULA, but the end result was that the taxpayer got screwed.
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One might have more sympathy for ULA once they are capable of flying without Russian engines.
That's a non sequitur. Parts is parts, and the Russkies make superlative engines. You don't have to start all over again for every company. NASA uses Russian engines too.
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What does NASA use Russian engines in, other than ULA rockets?
"Parts is parts" is a way of saying "you should only think about economics and technology, and not any of the secondary effects." This often leads to disaster.
I bet there are some industries that the North Koreans are really good at. We have a reason, however, for not giving them lots of dollars to spend on anything they want. The Russians are no different.
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What does NASA use Russian engines in, other than ULA rockets?
"Parts is parts" is a way of saying "you should only think about economics and technology, and not any of the secondary effects." This often leads to disaster.
I bet there are some industries that the North Koreans are really good at. We have a reason, however, for not giving them lots of dollars to spend on anything they want. The Russians are no different.
Well, tell me why the Russian Engines are not good for use, instead of just telling me I am wrong, because reasons.
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Having a dependency on the Russians for transport to ISS and rocket engines for US military payloads has tied the hands of the US when they really should have taken much more severe economic measures against Russia over the Ukrane.
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Having a dependency on the Russians for transport to ISS and rocket engines for US military payloads has tied the hands of the US when they really should have taken much more severe economic measures against Russia over the Ukrane.
Life in a world of globalization.
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Not worth the cost if it means you have to lie down with the likes of Putin, etc. You might save money and operate more efficiently over the short term, but the long-term expense is much larger than any short-term gain.
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Ever hear the saying "Fool me once, shame on you. Fool me twice, shame on me." Resentment taken to excess is silly, but at reasonable levels is simply a memory aid.
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Re:Good for SpaceX (Score:5, Insightful)
You can have $70M of your taxpayer dollars used on his rockets, or you can have $160M of your taxpayer dollars go to Lockheed Martin and Boeing. Your choice.
So:
* Cheaper by 55%
* Built entirely in America
* Doesn't give money to a country we're sanctioning
* No design elements from the 1970s
* Company is doing innovative things to drive down costs even more in the future
* Slightly more likely to explode
Seems like a good thing to me.
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You can do rocketry as ULA does; exactly like we've been doing for the past twenty+ years and have it cost exactly the same as it has for the past twenty+ years.
_Or_ you can invent new, _substantially_ more cost-effective ways of doing rocketry. Whenever you're doing something new in a high-energy field, there's a chance of explosive failure. (Remember Apollo 1?) Hell, explosive failure happens even when you're doing the same old thing. (Remember Challenger? Columbia?)
The only con SpaceX is revealing is the
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You honestly think Boeing and Lockheed haven't blown anything up and we've never experienced rockets exploding upon launch before when overpaid pork-barrel contractors are involved? Remember the Navy's kaputnik? Remember Challenger? Remember many test pilots killed in experimental planes? How about combat pilots killed due to the P-38's issues in a dive?
Stop being a shill. Rockets explode sometimes, especially ones that are innovative and new.
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There's plenty of obvious innovation. If you can't see that, you're either stupid or trolling.
To be a death trap, they'd have to kill someone in it first. So far they have yet to kill someone unlike previous NASA contractors.
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You can have $70M of your taxpayer dollars used on his rockets, or you can have $160M of your taxpayer dollars go to Lockheed Martin and Boeing. Your choice.
This is kind of how this is supposed to work. There will always be a place for Government launches, and the place for private launch companies will expand. I cannot understand why so many people cannot understand that, unless they are looking to end rocketry altogether.
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* Cheaper by 55% * Slightly more likely to explode
Seems like a good thing to me.
Which option is better really depends on what you're launching and what "slightly" is exactly. If you're launching the $8 billion James Webb Space Telescope and the risk is 10% higher with SpaceX, then the extra $90 million is going to be worth it.
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That space telescope cost $8 billion to develop. Making a second one exactly like it would cost an order of magnitude less.
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An order of magnitude less than $8,000,000,000 is still $800,000,000 - which is still an order of magnitude greater than the price difference between ULA and SpaceX. I won't begrudge NASA if they play it safe and go with a more reliable launch system for JWST.
Re:Hope this is true (Score:5, Insightful)
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Challenger was launched right before Reagan's SOTA address, which was a massive scheduling fuckup right there. Obviously in those circumstances there would be high-level pressure not to delay the launch, and that was confirmed during the post-crash investigation.
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Challenger was launched right before Reagan's SOTA address, which was a massive scheduling fuckup right there. Obviously in those circumstances there would be high-level pressure not to delay the launch, and that was confirmed during the post-crash investigation.
What happened even has historical president: "Will no one rid me of this troublesome priest?" [wikipedia.org]
Would be nice... (Score:5, Informative)
... to actually get to see a detailed breakdown of the cause of the last explosion, rather than having to piece it together from bits and pieces of what's been said so far.
So far, it seems that there was (expected) supercooled liquid oxygen seeped into the CF reinforcing fibers on the helium COPVs (as was expected), which was just above its freezing point. They then began loading cold helium. Had the oxygen stayed liquid, it would have squeezed out (expected behavior). Rather, the oxygen wasn't able to seep out fast enough, and the increasing pressure caused some of it to solidify, blocking the escape of oxygen from the CF. LOX is inherently unstable in contact with organics, including carbon fibre, and can detonate under high temperatures, high pressures, shocks, etc; it has to be handled gingerly. In this case, the pressure continued to rise as the COPVs filled, until the LOX reached a critical pressure and detonated - thus rupturing the COPV reinforcement, thus the COPVs, thus the second stage and destroying the vehicle.
That's what it sounds like happened. But it'd be nice to get that confirmed or corrected if inaccurate. If this is correct, there's a number of things they could do to remedy it; I'd think the most likely would be to fill the COPVs before loading LOX.
As a side note, I'm really uncomfortable with their plan to make IPS entirely out of carbon fibre. As they're finding out (and has others have found out in the past), it's really difficult to use LOX with composites. And perhaps most importantly, inconsistently difficult. And the failure modes can be catastrophic - instant explosive rupture at the point of failure. Aluminum is not only light, but (by pure coincidence) one of the easiest things to work with LOX, as the oxide layer does a good job protecting the metal (even still, aluminum can detonate in contact with LOX in the right temperature/pressure/shock conditions, but said explosions are only self-propagating under significantly elevated pressure conditions). Also coincidentally, aluminum-lithium is even more resistant to reaction with LOX than lithium-free aluminum alloys. Basically, rocket manufacturers have been "having it easy" working with LOX by virtue of making rockets out of aluminum. You give that up when you go to composites.
But.... it's their rocket company, I guess we'll see how it goes.
Re:Would be nice... (Score:5, Interesting)
We probably have ITAR to blame for not being able to read the full report. You can make all the FOIAs you want, ITAR is always going to be the excuse because all of the details of using a COPV successfully in a rocket is for the moment a trade-secret of a US company which the country doesn't want to hand over to North Korea, etc.
Besides it being their rocket company, they are making every effort to optimize delta-V over weight when nobody else in their market is trying. Otherwise, they would be using metal tanks and not attempting a high-risk technology like densification. You're going to blow up a few rockets if you take those risks.
Re:Would be nice... (Score:5, Insightful)
LOX is unstable in contact with most organics. To the point that with the exception of some fluoropolymers, it's generally considered that all organics have a critical pressure in which they'll spontaneously combust with LOX. For many organics that pressure is below atmospheric pressure (aka hypergolic). For most plastics it is above atmospheric pressure, but not tremendously so. This includes the epoxy binders used in composites.
Yes, CF is the standard abbreviation for carbon fibre.
The LOX is supposed to be squeezed out of the CF as the COPVs pressurize. The COPV are comprised of a non-permeable aluminum inner liner and a permeable carbon fiber overwrap that bears the load. By freezing solid, the LOX was unable to escape the overwrap as the pressure increased as the COPVs were filled, and was correspondingly pressurized inside of it.
The system was not "designed so that it has areas which are likely to detonate". The LOX was supposed to be squeezed out of the overwrap, not become trapped in it as SOX.
None of their statements that I've come across mentioned "heating". They did, however, mention that the solidification of the LOX led to a pressure buildup. I've read quite a few LOX handing guidebooks (for working on a project involving LOX), and LOX pressurized against carbon fiber is considered an explosion hazard. You don't even store LOX in composite containers in low pressure conditions long-term. You know the main differences between a LOX dewar and a LN2 dewar? The latter often has either no lid and/or contains plastic or composite or silicone components. The former always has a lid and does not contain (non-fluorinated) plastic or composite components, and rarely silicone (fluoropolymers are usually okay). Also some metals don't work with LOX either.
It's not a case of "you say detonation, I say combustion". The spontaneous pressure-induced reaction of LOX and CF is a detonation. The rocket as a whole however was primarily consumed by a deflagration (non-supersonic combustion) between LOX and RP-1.
Nowehere in anything that I've seen from them were "sparks" mentioned.
Your "sparks" and "temperature" comments are directly in contradiction to SpaceX's comments about the conditions causing the formation of SOX and preventing the egress of LOX from the overwrap.
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Re:Would be nice... (Score:4, Informative)
Every year or so, I stand on Pad 34 and someone tells the story of Apollo 1. I remember the day it happened, too. It's one every engineer should hear.
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Which undoes the primary reason for loading the helium after the LOX, and the primary reason why the helium tanks are in the LOX tank in the first place - cooled to LOX temperatures, the helium tanks can hold more helium than at ambient. What they'll probably do is control the helium pressure more carefully prior to and during LOX loading to prevent the tanks f
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One issue is that Helium non-intuitively cools off when pressurized. Filling the helium tank froze the oxygen.
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No, it cools off when high pressure helium is valved into lower-pressure tanks, like freon through an air conditioner expansion valve.
Helium and hydogen are unusual in that they *don't* cool when this is done at room temperatures. They *do* when you do it at liquid air temperatures. That's one of the reasons (their extremely low boiling points being the other) that they were the last gasses to be liquified.
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It also depends on the way the helium is expanded. In free expansion, it'll cool and gain a large amount of kinetic energy. If expanded through an insulated porous plug, it'll gain a small amount of kinetic energy but heat up. It's basically down to where the energy released in the expansion ends up.
As the helium swirls around the tank, turbulence and friction will convert the kinetic energy it gained in expanding into the tank to random heat. However, when it is released into the tank, I'd expect it to coo
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They then began loading cold helium. Had the oxygen stayed liquid, it would have squeezed out (expected behavior). Rather, the oxygen wasn't able to seep out fast enough, and the increasing pressure caused some of it to solidify, blocking the escape of oxygen from the CF.
So if I understand the logic of these tanks correctly: The He tank necessarily is at high pressure relative to the LOX tank, as it will be pressurizing the much larger LOX tank as it empties. CF is strong enough to hold the tank together against this pressure, but can't prevent seepage through it. The aluminium layer prevents gas escape, but contributes little to the structural strength of the tank - hence when filled, it expands like a balloon until the CF prevents further expansion, which necessarily comp
Re:Would be nice... (Score:4, Informative)
Indeed, and sometimes COPVs designed for other uses have various outer linings or coatings to protect the CF. But this comes with mass penalities. And rocket engineers are anything if not focused on not including any mass that they don't feel that they absolutely have to. And remember, SpaceX had no problem with their COPVs exploding prior to this one event; none of their testing had previously induced an explosion. So it's understandable that they'd have felt that it was fine. But LOX can be a harsh mistress. Not as unpredictable as, say, H2O2, mind you. But reading through past LOX incidents can be enlightening. For example, the Bell X1-D - it ultimately turned out to be that the gaskets had been treated with a softener, and that softener got into the LOX tank - and as soon as the tank started pressurizing, they hit LOX's critical pressure with the chemical and it detonated.
It's worth noting that the prototype ITS LOX tank that they made (also CF) is linerless. No coatings at all, just bare CF. Now, that's a different situation, it's not part of a helium COPV and thus not subject to the exact same failure scenario. But one doesn't have to wrack their brain too hard to come up with other failure scenarios related to transient impact, friction, general heat, bending or shock (all things that can set off LOX reactions). With aluminum, LOX reactions require fairly severe conditions, and generally self extinguish. With CF, that's not the case.
But perhaps I'm too much of a pessimist. I really want SpaceX to prove me wrong here and show that you can make safe, reliable LOX tanks out of CF :)
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Some nits:
(1) When they started loading the helium, it was cold, presumably cooled like the LOX was -- by boiling off liquid N2 in sub-atmospheric pressures, to perhaps ~60-65 Kelvin.
(2) Valving the helium into the COPVs involved valving it into the low-pressure COPVs, causing it to cool. Doing this at room temperature, helium (or hydrogen) will not cool, but at liquid air temperatures, it will work like an air conditioner expansion valve. Apparently...
(3) This cooled at least parts of one COPV to below 54K
Re: Would be nice... (Score:4, Insightful)
As a side note, I'm really uncomfortable with their plan to make IPS entirely out of carbon fibre. As they're finding out (and has others have found out in the past), it's really difficult to use LOX with composites.
Well for one thing the pressure in a COPV is several orders of magnitude higher than in a LOX tank so it seems foolish to over react to a failure of composites under extreme pressure and exotic conditioned when future applications will be different in nearly every way. Secondly, you could always work exactly the same as a COPV and line the interior of the composite structure with a thin layer of aluminum to prevent any contact at all. In fact we don't even know if that's not already the plan. In this instance SpaceX simply didn't think it was necessary to prevent contact of LOX and carbon and they were arguably right until they pushed the conditions slightly too far, it's telling that they are returning to flight with the exact same hardware.
You can't radically upset the economics of space flight by doing the exact same things the exact same way everybody else has always done it. You'll end up with the same thing at the same price.
Vandenberg weather horrible next Weekend (Score:3)
Vandenberg AFB is forecast to have 50% chance of precipitation Saturday, 80% Sunday and 60% Monday.