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« SpaceX Update | Main | Huh? »

Post Mortem

Clark Lindsey has lots of links and thoughts about yesterday's loss (not a permalink--just keep scrolling). I agree in particular with this:

As Elon Musk has said, expecting a rocket to work perfectly the first time is like expecting a huge, elaborate software program to run bug-free the first time it is run. (Fortunately for programmers, a computer usually doesn't burst into flames if there is a fatal bug.)

This is why I and many other alt.spacers prefer space transports that can be tested incrementally rather than requiring "full up" performance the first time out. While the Falcon is partially reusable, it doesn't offer the "fly a little, test a little" capability of vehicles with flyback stages. The SpaceShipOne test flights, for example, revealed several significant design problems but the increments in the system's envelope expansion were always small enough that the flaws did not destroy the SS1. Instead the pilots were always able to return the craft safely and the particular problems found during a test were fixed before the next flight.

Yes. That's the one thing that's remained "old school" in SpaceX's approach. You can test subsystems until the end of time, and still not know if the entire beast will work together perfectly, all singing, all dancing, the first time. NASA took this approach with the Shuttle, and got away with it, but they spent a hell of a lot of money on it. This is why it's nice to have vehicle that's not only recoverable, but one that lands the same way it takes off, so that it can be incrementally tested. Now that some other companies are starting to take that approach (both horizontal and vertical) it will be interesting to see how much more of an incident-free (or at least vehicle-loss-free) test program they have.

In the meantime, good luck to SpaceX. There's no reason to think at this point that they can't be as successful, ultimately, as their predecessors that cost much, much more to develop, but still had early failures.

[Update in the late afternoon]

Other people are having similar thoughts:

I guess that when you have an incredibly complicated system like Falcon or like other existing orbital vehicles, where everything has to work just right, there are almost no margins, and nothing can be flight tested beforehand, risks and sucky days like these are inevitable.

I'm glad that for our suborbital vehicles we will be able to do things like cutting our teeth on takeoffs and landings hanging under a tether. While we'll still probably have our ulcer-inducing moments where we have to push the envelope into some new regime that we haven't tried before, and where something could go wrong, those will be fewer and farther between. Trying to get every part of a rocket vehicle like that, with all the subsystems working perfectly from the start is a real challenge. SpaceX has a phenomenal crew, and I'm sure they'll get this figured out, and probably make a whole bunch of money on this, but I'm glad that the approach they're taking is not the only way to solve this problem.

Posted by Rand Simberg at March 25, 2006 09:07 AM
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Excerpt: the meme about SpaceX's chosen method that has been forwarded by quite a few members of the space blogosphere: namely, that ELVs are more prone to failure than a launcher that you can 'test incrementally.' as opposed to one you 'have to test all-up.'...
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Despite the failure I assume SpaceX still got paid by DARPA. Very good for SpaceX, but a less good incentive system, despite the fact that DARPA was clearly funding a test launch. I wonder if there were any additional potential fees SpaceX may now have to forfeit since they failed? I wonder if their insurance costs will increase? Would SpaceX then increase their prices to cover higher included insurance or would they accept lower profit? Hmmm.

Posted by anon at March 25, 2006 11:27 AM

Musk said it himself last fall:

"Nobody said rockets would be easy, but it was harder than that."

Posted by Monte Davis at March 25, 2006 11:52 AM

SpaceX has put their marker on the ground for prices, so they'll have to eat the costs or take a huge hit in rep.

I wonder... could they have tested a scale model of the thermal blanket separation event with a sounding rocket? Is there anything else that they could reasonably test with one?

Posted by Big D at March 25, 2006 12:04 PM

Isn't falcon an orbital vehicle, whereas spaceship one only needed to fly suborbital a bit? That would account for a huge difference in the amount of fuel required, which would explain why the falcon rocket can't take off the same way it lands. In fact, there's almost nothing plane-like about a vehicle that can make it into orbit.

Posted by Aaron at March 25, 2006 01:36 PM

Pioneers catch most of the arrows. Better luck to 'em next time up.

Posted by The Sanity Inspector at March 25, 2006 01:41 PM

In checking out SpaceX's website, I am struck by the arrogance of it. EELV replacements? Manned capsules? And then there's the silly lawsuit against Bolocks because the AF doesn't take Musk seriously as a competitor to the bigs? This may have played well with investors if everything had gone right, but now it just makes them look bush. With a little humility, SpaceX may have been able to move on and improve, now they've got one more shot, and if it doesn't work their credibility will be piffed.

Posted by K at March 25, 2006 01:56 PM

Isn't falcon an orbital vehicle, whereas spaceship one only needed to fly suborbital a bit? That would account for a huge difference in the amount of fuel required, which would explain why the falcon rocket can't take off the same way it lands.

That problem is addressed by doing initial flight testing with light propellant loads.

Posted by Rand Simberg at March 25, 2006 02:14 PM

I suppose that might work for a vehicle that also has a control system or parachute that allows it to land, as well as being able to take the landing loads.

Nice site BTW. I have a space webblog of my own. (For some reason, it thinks the name is "questionable content"?) Here it is with some spaces thrown in

Posted by Aaron at March 25, 2006 03:10 PM

I can't allow Blog spot domains in comments, because I get so much spam from them.

Posted by Rand Simberg at March 25, 2006 03:33 PM

I think I detect just the first whisper of back biting and second guessing being directed to Elon and his people. Particularly, I must say to the person calling himself "K", I think SpaceX's law suit is very appropriate. DOD is attempting to set up what amounts to a cartel that would freeze out not just it but every other entity that dares to compete with Boeing and LockMart. This sort of thing I should think would be opposed by anyone who says that they want a free market in launch services.

Posted by Mark R. Whittington at March 25, 2006 04:04 PM

On the plus side: when the rocket impacted, the satellite was thrown high in the air and came down through the roof of SpaceX's machine shop mostly intact.

Posted by Ed Minchau at March 25, 2006 04:48 PM

"The rocket impacted on a dead reef about 250 ft away from the launch pad, so most of it is recoverable for analysis.

Amazingly, the satellite was thrown high into the air when the rocket impacted and came crashing down through the roof of our machine shop, landing mostly intact on the floor! One helluva' return trip.

The hole in the machine shop roof is the only significant damage to the island."


Posted by bruce Hoult at March 25, 2006 04:50 PM

After reading the thing from Elon about the fuel leak causing the accident I can't help thinking back to what Konrad Dannenberg told me one time after seeing one of our engine tests at Space America.

Just remember one thing: LOX Kerosene Systems LEAK.

A LOX leak caused our engine explosion on the pad.


Posted by Dennis Ray Wingo at March 25, 2006 04:51 PM

I wonder what SpaceX could have done with a hundredth of the half-trillion dollars Bush has spent on trying to keep the tanks of SUVs full?

Posted by Ian Campbell at March 25, 2006 06:43 PM

I think you need more tinfoil.

Well, at least the AF students get their satellite back and can either attempt a repair or hang it in the school museum.

Posted by Big D at March 25, 2006 06:58 PM

Just remember one thing: LOX Kerosene Systems LEAK.

I'm curious - is this just good safety advice for any liquid fueled rocket, or is there something particularly leak-prone about LOX, kerosene, or their combination? Is the cryo LOX plus warm kerosene particularly plagued by differential thermal expansion?

Posted by Roy S at March 25, 2006 09:37 PM

Does SpaceX still get paid by DARPA for blowing up their rocket, or was the contract only for actual delivery of the satellite in orbit? Certainly the Air Force satellite was paid for by the government.

While lots of people express their condolences for SpaceX, I think we should remember that taxpayer dollars were lost here. That's our money that blew up.

Posted by Tim Grant at March 26, 2006 07:59 AM

Any chance the payload is repairable/relaunchable?
IIRC, this was done with an AMROC payload when their launcher burned and fell over in its pad, some years back...

Posted by Frank Glover at March 26, 2006 11:32 AM

Big D,

You really think that Iraq had nothing to do with oil? If so, you're the one that needs the tinfoil.

Posted by Ian Campbell at March 26, 2006 11:43 PM

Yeah, we're just *swimming* in the oil that we "stole" from Iraq.

Yes, it has to do with oil indirectly, in that the countries most encouraging their populations to hate us happen to be the ones supplying the world (if not us directly, it doesn't matter, oil is a fungible commodity and we still can get hurt) with oil. That limits our options, and forces us to play a lot nicer with those harboring our enemies than we'd like.

What the war really has to do with--and yes, Bush was saying it back in 2002, a lot of people just ignored it--is overthrowing most of the region's governments and replacing them with democracies that are less likely to support terrorism (partly because it isn't needed as an outlet), and more likely to respond to diplomatic/economic actions than the current regimes.

The enemy has a say in this--and we have a number of different enemies, for a number of different reasons (most of them revolving around power and control). Some of them decided to turn Iraq into the main campaign; if they lose there, and are *shown* to have lost, they will lose a substantial amount of support--that old draining the swamp thing. If we lose there--or declare it lost, same thing--then they will reap enormous accolades, and proceed from there.

Not that this really has anything to do with SpaceX, though.

Posted by Big D at March 27, 2006 07:47 AM

Big D,

True, Space X had nothing directly to do with Iraq or vice versa. But indirectly, Bush decided for whatever reason to invade Iraq. He is on course to spend FIVE HUNDRED BILLION dollars on this adventure.

This amount is easily enough to get the US a real presence in space, start exploiting its resources, including energy, and make the Middle East irrelevant by removing the only real reason why anyone in the West is interested in the region in the first place.

And the way to do it would not have been to give the cash to NASA, but to issue a series of prizes. Example: 20 billion dollars to the first company to build a functioning Moonbase that stays operational for a year with 10 people.

But war presidents usually get re-elected, and Bush wanted to please his construction and oil magnate buddies, to say nothing of the chewing-the-walls nutty religious Right, and so we are where we are.

The guys out there are doing a fantastic job, but should never have been asked to do it.

Posted by Ian Campbell at March 28, 2006 01:16 AM

"This is why it's nice to have vehicle that's not only recoverable, but one that lands the same way it takes off, so that it can be incrementally tested."

So what you're essentially saying is that you are right and every other rocket engineer since the dawn of rocketry has been wrong?

Playing devil's advocate here, if you're right and the solution is so obvious, then why hasn't anybody done it like this before? Why is nobody doing it like this now?

Posted by Bill Holloran at March 28, 2006 09:26 PM

Playing devil's advocate here, if you're right and the solution is so obvious, then why hasn't anybody done it like this before? Why is nobody doing it like this now?

Because of a long history, in which we were in a hurry to get to the moon, and decided to use converted ballistic missiles (and designs based on converted ballistic missiles), which has resulted in a design inertia, in which people tend to go with what's (sort of) worked in the past, to minimize risk. Several people have started to take this approach (X-15, DC-X, and now several of the new startups), but until now it hasn't been funded because the previous ways of doing it were good enough for the existing market.

What do you think is wrong with the concept of being able to incrementally test? What is it that's good about having to do it all up, on the very first flight?

Posted by Rand Simberg at March 29, 2006 04:52 AM

What do you think is wrong with the concept of being able to incrementally test? What is it that's good about having to do it all up, on the very first flight?

I think it's a bit disingenuous to suggest that incremental testing is somehow cheaper, faster or superior. On the contrary, if Falcon 1 had been designed from the start to fly a little, then return to base, then fly again, it would have been structurally heavier and had a higher mass ratio.
An orbital version would have required much larger or multiple engines on each stage, and would have consequently been much more complex, which means more time and hence money would have had to been spent to get to the first launch.
Not to mention, NONE of that would have prevented a leak like the one that occurred from causing a fire that would entirely destroy the first flight vehicle.

Spacex tested the engine and the vehicle many times, and even did a full holddown fire at vandenburg last year, if you'll remember. No leak suggested itself.

In fact, a single failure of a larger, more complex vehicle that had taken more time and money to develop would have been crippling to the entire program.

Posted by cuddihy at March 29, 2006 09:58 AM

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