Woah! J-2X? I thought that the J-2 technology was as lost as Atlantis.

(Yeah, I'm a little late to the whole next generation of NASA manned spaceflight thing.)

In the case of the nuts we made, there was no way they were worried about corporate espionage (and someone who had merely copies of the documentation that went along with the parts would know everything they needed to about the components), it was purely in the interest of meeting Federal regulations and covering their rears in case of a lawsuit. I'm sure its the same way with the shuttle, for the most part.

If a part falls off an airplane in flight, an awful lot of people can suddenly have a very bad day, so they simply have to do everything they can, to make sure that nothing can go wrong. With precise information on a part, engineers can calculate with a high degree of accuracy when that part is going to fail. This enables them to write the end of life specifications for the part, and can ensure that it is removed from service before it has a chance to fail. It also enables them, in the case a part fails unexpectedly, to backtrack through the entire process and pinpoint anything that might have gone wrong, which led to the premature failure. If it turns out that nobody did anything wrong, they can move on to other causes for the failure, and once that's been discovered, they're able to insert any changes that might be needed to prevent the problem from occurring again, at a specific point in the process.

I've read on the intarwebs (so take it with a grain of salt), that if a fully fueled shuttle were to blow up on the pad, the blast would be several kilotons, which would no doubt cause tens of thousands of people to be killed or injured. That's not the sort of thing you want to leave to chance, and trying to find out exactly what went wrong is probably a wee bit difficult if nearly everything gets vaporized in the initial explosion. Were it not for all the documentation, we wouldn't have been able to figure out what caused the Apollo 13 explosion, since the service module burned up on re-entry.

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We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

There's little margin for error simply because weight is such a huge issues. Thus, each part must perform exactly to specification or better, as there is no redundancy to allow for overengineering.

It's a lot of energy released in very short time, but it's a very rapid burn, not an explosive bang. It'll make a lot of noise, release a lot of heat, and blow out quite a few windows.

But it wouldn't kill thousands, particularly as there is a sizeable buffer zone around the launch pad for precisely that reason - in case it does undergo catestrophic failure.

If even a tenth of that energy were released in 1/1000th of a second, however, the shock wave would flatten buildings.

Not so with a complete shuttle disentegration.

And in other news, the dinosaurs went extinct.

The specs of J-2 were more than good, so an improved version should theoretically be an excellent rocket engine, even at today's standards.

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It would definitely not kill "tens of thousands", even if a 13 kiloton atomic bomb were detonated at the launch pad.

The closest public viewing area is about 6 miles from the launch pad. They could safely view a Hiroshima-size atomic bomb from that vantage point with no protection whatsoever.

Launch control is 3 miles away, but protected inside a building.

Even if the entire launch vehicle is vaporized in an explosion, there are thousands of data parameters, some recorded at 100 or 1000 hz. The vehicle is so heavily instrumented it has a virtual "black box" flight recorder via telemetry.

As I said, its something I read on the intarwebs, and not to be consumed without a grain of salt.

How far's the debris going to fall, though? And what direction is it going to take?

Which still doesn't mean you'll be able to pin down the exact cause for the explosion, however. If, before the explosion, a couple of monitoring systems go off-line and stop reporting data, it can be difficult to determine which components caused the problem. Additionally, even if you know that the explosion was caused by turbopump 11a failing, without knowing how that pump was put together, figuring out how to correct what went wrong is going to be insanely hard.

First of all, you need to know what on the pump failed. Was it a bearing? A blade? A valve? Something else? Depending upon what went wrong, you might have very little data on the origin of the problem. Suppose a sensor went bad, and it thought the valve was open (as it should have been), and this led to the explosion. You've got to sift through the data to first find where the explosion originated, then you've got to sort through the data from those sections to try and sort out which one of them caused the problem. If all those readings are correct, then you've got go through other data to find any clues which indicate where the problem was.

Next, you've got to try and duplicate the problem (to better understand it, and figure out how to correct it). What if, however, you can't duplicate the problem? If the pump that blew had something unique happen to it, you've got to go and try to replicate the process and figure out what could have gone wrong, and why. With everything meticulously documented, you can go back through the manufacturing process of the specific pump that failed, and see if anyone did something they weren't supposed to.

Even with all that documentation, you still can't be 100% certain that you found the exact cause, only the most likely cause. The Apollo 13 explosion could have potentially been caused by a micrometeorite, but based on the evidence we do have, and the odds of it hitting a tank that was improperly manufactured, it seems likely that it was not a micrometeorite. The causes of an accident won't always be so clear cut, though.

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We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

Gotta love the Internet - so reliable.

A mile or three, at the most.

Predominantly downwind.

Given the several hundred hardwired systems, as well as video from fifty angles, I think it would be exceedingly difficult for a shuttle launch to fail on the pad without being able to discern EXACTLY what went wrong.

Consider the Challenger disaster - how many miles up was it? And we nailed the problem.

Launch pad? No problem.

Of course those steps would be taken. My point was your statement that it's "difficult if nearly everything gets vaporized in the initial explosion."

Whether you have residual parts or not, during launch there are thousands of instrumentation parameters being recorded at high speed.

One reason that much data is telemetered and recorded is for possible forensic analysis after a disaster. The engineers know they may not get any post-explosion components.

That data, combined with meticulous manufacturing and test documentation, generally allows any problem to be solved regardless of whether any post-explosion parts are available.

I'd like to see your figures backing that up.
They tend to launch when there's not a lot of wind.

Yes, because we found the debris, primarily the SRBs, and we had oodles of documentation of every step of the manufacturing and assembly process. Without recovering the SRBs and the documentation, it would have been much harder.

Yes, thanks to the levels of documentation we have, it would be possible.

__________________
We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

Which is my point as to why Boeing requires so much documentation on everything for aircraft and NASA does for the shuttle.

__________________
We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

No wonder everything costs so much!

Would a company like SpaceX have to provide that level of documentation if they launch NASA or other government payloads?

CJSF

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Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

I believe they do. The government has allowed wavers of some aspects of civilian space launches, but I don't know it that applies to things like documentation or not. I know that Rutan pulled out of building some things for NASA because the level of documentation involved was way higher than anything he'd ever dealt with before (and to be fair, much of the documentation required things which were unnecessary for his size of an operation, but would have been appropriate for a larger corporation).

__________________
We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

Wikipedia quote: "Launch Complex 39 (LC-39) is a rocket launch site at the John F. Kennedy Space Center on Merritt Island in Florida, USA. The site and its collection of facilities were originally built for the Apollo program, and later modified to support Space Shuttle operations. NASA began modifying LC-39 in 2007 to accommodate Project Constellation.[1][2] Launches from LC-39 are supervised from the Launch Control Center, located 3 miles (4.8 km) from the launch pads. "

The LCS isn't designed to handle nuclear blasts. It is well-suited to handle on-pad blowups three miles distant.

Not a lot, true. Still downwind.

Undoubtedly. But not impossible, as the ascent video clearly shows the breach. Armed with that and and the unmistakeable failure, the forensics folks would put the sections through the wringer until the failure was repeated, thereby providing evidence as to the cause.

Your figures for how far the debris would fall. Remember debris from the WTC ended up scattered a lot farther than three miles.

So? If you'll recall, I never claimed with any certainty the level of damage which would be wrought by a shuttle going up on the pad. And "handling" a blast can mean that the building's still basically trashed, but the occupants inside are okay.



Winds blow in a variety of directions. Some times they blow north, sometimes south, sometimes east, sometimes west. And occasionally, they've been known to blow in a combination of those directions. Additionally, winds can blow at different directions at different altitudes.



It shows a breech. Without the SRBs, you couldn't say that was the only breech, and you'd still have trouble pinning down what caused the breech. Was it a manufacturing defect in that particular SRB? Was it the O-Ring? Did the SRB somehow flex beyond its design limit? Or was it some other problem?

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We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

They didn't HAVE the SRBs -- they were blown to smithereens by range safety destruct charges, shortly after the vehicle breakup.

The fished out some SRB fragments, but this WAS NOT essential to understanding the problem.

Video and instrumentation clearly showed SRB joint seal leaking, right upon takeoff.

Roger Boisjoly, the Thiokol engineer most familiar with the SRB O-ring problem, tried to stop the launch. When he was overruled, he couldn't bear to watch the liftoff as he felt the vehicle would blow up on the pad due to an O-ring failure. He was surprised it survived 73 seconds.

This illustrates when the accident happened, knowledgeable people were already well aware of the exact problem. The flight instrumentation and videos verified that. They wouldn't have had trouble pinning down the problem cause, even without any SRB fragments.

There may be cases where recovering post-accident debris is more central to understanding the problem, but Challenger isn't one of them.

Direct 3.0 or any future launch system will be similarly instrumented, with similar documentation trails. As Challenger illustrates, recovering post-accident debris isn't necessarily essential to identify the root problem.