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Soyuz Damage May Delay Space Station Trip
SeaDour writes "As if the failed oxygen generator on the International Space Station wasn't bad enough, rumor has it that the planned launch of a Russian Soyuz capsule to change crews onboard the station may be delayed due to a mishap during ground testing. Apparently one of the small explosive bolts, used to separate sections of the capsule during landing, prematurely exploded, which means the bolts may all have to be inspected for defects. Russian space officals haven't officially confirmed any delay of the October 9 launch date, but I'm sure it's something the two astronauts on the station are thinking about as they repressurize the station with reserve air supplies."
So, if the oxygen generator fails, they don't have redundant oxygen generators with a fail-over mechanism, to work uninterruptedly? Are they too huge that they have just one, and depend on reserve supplies? I hope they get the supplies soon. Perhaps, when China also launches their space vehicles, we will have more countries to rely on in case of space emergencies.
They're doing OK - don't knock them. Some things go spectacularly well, and some pretty badly, but most go acceptably.
"Do not drill any holes in your cat - it will not like it."
-- Nick Davies
The 'explosive bolts' mention don't actually explode. The correct name is 'frangible bolt'. A small charge goes off inside it and breaks down the structure so it seperates cleanly. 'Explosive bolt' suggests that it goes off like a firecracker, but shooting shrapnel around inside a million pounds of cryogenic fuel and delicate machinery would be unwise.
Also, in response to the post that asked why there were so many problems w/ spaceflight, there's one thing the responders failed to mention: assembly line quality.
If you build 30 soyuz capsules over a 30 year period, each one is still very much like a craftsman assembled item. If, on the other hand, you build 100 devices of similar complexity in a year, then you can have real assembly lines with better inherent quality. The defects/flight and cost would drop dramatically if there were more spacecraft being built. Check the quality of the pre-Ford cars against the Model T, and the difference is immediately apparent.
I suspect that a decade of funding neglect is what's causing such heartache for the US and Russian space programs. I wonder how long before the Chinese surpass them and set up their own space station? Given the general living conditions in the former USSR (yes, I've spent months living there), I can't see a sustained effort from the Russians for much longer. And the Americans don't seem interested anymore - the space-race ended years ago, and it no longer makes headlines unless everyone dies. I guess I better enroll in Mandarin classes... :)
NASA Said it had never happened...
Apparently one of the small explosive bolts, used to separate sections of the capsule during landing, prematurely exploded, which means the bolts may all have to be inspected for defects.
Now it has happened again.
The problem isn't (necessarily, though i'm not sure of it) that spaceflight is that much more complex. The problem is that there is a much smaller margin of error.
Airplanes can have roofs peel back, engines fall off, and all other of pretty bad things happen, and yet the planes often manage to come in for a safe landing anyways. A spacecraft has a (comparitively) small hole poked in it by some foam and the entire thing disintegrates during reentry.
Spacecraft deal with more extreme conditions and are much farther away from help, so even when something small goes wrong it can go _really_ wrong.
This Space Intentionally Left Blank
While it's true to a degree that space flight is inherently more difficult than atmospheric flight, that isn't the sole, or even the main factor contributing to the unreliability of space flight. It's also not really a problem of using old equipment. In fact, the problem can be considered using new equipment. Don't worry, I'm not crazy. Read on.
The Wright Brothers crashed several times before their first powered flight, and they crashed on their third flight, and they crashed several times more in the years following that. It was part of starting out. Compare that with now. Every part in an airplane is rigorously tested, at least in the prototype. Most parts are "off-the-shelf," which not only makes them cheaper, but means the engineers can become familiar with their failure history and plan ahead. Even the newest designs are based on one that worked well before.
In the space program, however, everything is new. The oxygen generator was built specifically for the space station. It was tested in the lab where it was built. At best, it was designed and built by applying lessons learned from a handful of similar devices before it.
Remember, NASA is about developing technology. In a way, the space program now is sort of like a software program in its alpha test stage. A lot of lessons will be learned and a lot of bugs will be identified. In the next few decades, companies like Scaled Composites will produce vehicles that better fit the description of Beta releases. Maybe it won't be too long before we're asking if interstellar travel is really that much more difficult than flying to Mars.
Yah, beacuse the reusable shuttle sysem is so much cheaper than the one time use rockets it replaces.
If it only has to work once, then it is a lot simpler and a lot cheaper to build.
I'm no rocket scientist, but exploding bolts have always seemed like an engineering cop out to me.
Engineer A: "Lets see...we have these two parts that need to be held together really tightly and then released very quickly"
Engineer B: "I have an idea, let's just build the whole damn thing out of plastique or some shit, that'll work great"
A: "Good show ol' chap. That will work fine and dandy indeed."
jokes aside, what are the compelling (practical?) reasons that exploding bolts seem to be so common in spacecraft?
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