OT: Welcome home, Discovery

Since I work at NASA, it was a relief to watch them come in with a perfect landing. Here's to the brave crew and the space program starting up again.

Reply to
badgolferman
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I second that. I've had nothing on my den TV but the NASA channel for the past two weeks. They all did a great job.

Reply to
Dbu.

I've been watching the shuttles come and go since the very first on. I woke up early for three days to watch the first one go up, and drove out to Lancaster to watch one of them land -- but got a late start and missed the show.

The thing with the falling pieces seems to have been around for quite awhile, well before Colombia went up in disaster.

Didn't they used to paint the external tank wiith something to hold it together on the early flights? Or, maybe they painted the tank for another reason, and holding it together was a byproduct. In any case, what's the problem with painting the tank again to hold the foam on?

In a semi related area, why can't they put plexiglas on the belly of the shuttle to protect it from strikes in the event the foam comes off? Maybe plexiglass is a bad choice of material, but the point is that it seems to me that there could be a protective layer of something that is expendable on re-entry that would protect the heat tiles during launch. The foam seems to be in the range of a pound or two, and this wouldn't require steel plates or anything to deflect them away from the craft, all that would be needed is a thin layer of plastic or aluminum that could be jetisoned after the tanks blow off, or simply burn off on re-entry.

Reply to
J Strickland

Weight of the paint and the type used was environmentally toxic.

Reply to
badgolferman

Since you work there, maybe you can answer a question that is making the rounds.

Around 1998 or so, the EPA was allegedly pressured to change the method by which the foam was applied to the external tank. The new process does not use CFC's but does not work as well, shown by the break-offs.

Was this change, in fact, responsible for the deaths of the Columbia astronauts? If the older process is safer and more effective, why is NASA so reluctant to go back to the old method?

Reply to
user

From what I understand the tile that came off was not given the same attention that other areas had post Colombia. So I suspect they will scrutinize the heck out of it and give it the same treatment as the other parts of the tank. No tiles fell off from the other areas. The shuttle is due to be replaced by the next generation vehicle in a few years. The new design shuttle will sit on top of the fuel tank which means anything falling off will not have a chance of striking the shuttle.

Reply to
Dbu.

Back when they stopped painting the external tank, I remember hearing that it was done to save money because the paint was only for looks in the first place. It makes sense not to spend money to make the tank look pretty when it is going to burn up in the atmosphere anyway.

Reply to
Truckdude

My guess is that the shuttles pose a significant environmental problem when they burn up, not to mention when they hit the ground. It seems to me that they should give up a bit of payload, or add some more fuel, for the protection that the paint offers.

Don't get me wrong here, I'm no one to second guess NASA, and I like space flight. So, I'm just trying to explore ways to make space flight work a bit better.

Reply to
J Strickland

Well yeah, but there are still flights planned for this generation, and if it takes a coat of paint to make them safer, then I say, "let's paint them." The paint can't possibly do as much damage as shuttle parts falling on a shoolhouse, or in themiddle of downtown. Not to mention the human cost of losing a flight crew ...

They either need to catch the stuff that falls off before it falls off, or cover the underside of the shuttle so that stuff that falls off won't hurt.

Reply to
J Strickland

Yes, but when the paint is holding the foam on, who gives a shit if it is pretty, it's a safety measure.

And, it falls into the ocean, it doesn't burn up. The tanks never make it out of the atmosphere, so they don't burn up on re-entry.

Reply to
J Strickland

You're saying to paint over the shuttle tile? Which would protect it from falling foam insulation off the tank? Do you think paint would protect the tiles from the foam hitting the shuttle and poking a hole in the tile surface? I guess I don't really know, but knowing engineers, they most likely have studied the hell out of thies and ruled it out, that's just a guess. I think there is about 25 more shuttle flights left before retirement.

Reply to
Dbu.

At this point in time it seems to me that the changes they made in other parts of the external tank to correct the foam falling off should work in the areas they did not look at and apply to. Post Columbia I'm sure they will analyze the hell out of it and come up with a fix that sticks. Important thing I noted, NASA is stressing this is and will be considered a test vehicle. Something that they lost in the past. In the past it got to be like a routine airplane flight, which was a big mistake.

Reply to
Dbu.

I thought they made a change to the way they applied the foam to the entire tank, or at least the side next to the shuttle. If so, then whatever they did didn't work because pieces are still falling off.

Reply to
J Strickland

No, paint the tank tiles, or whatever the foam covering is. (I don't think the tank is tiled, it's coated.) The main point here isn't the material, it's holding the material on, OR protecting other material from the affects of material that falls off.

Which would protect it

I think the tiles on the shuttle proper can be protected with something as low-tech as plexiglas. Plastic will take the hit from the 2-pound chunks of foam and not let the tiles be damaged. What I am not taking into account, and what has to be considered, is what happens to the plexiglas later in the flight. What if parts of it burn up, and larger chunks then fly around and hit something important? Can plexiglas be attached in a manner that can be jetisoned later in a controlled fashion? Can plexiglas be affixed as a shield between the external tank and the shuttle, then fall away with the tank when it gets to altitude? Of course, this is weight, and it takes away from payload, and that has its own sets of problems.

Seriously, why not wrap the tank in SaranWrap and packing tape to hold the foam in place, then leave a science experiment on the pad because of the weight of the SaranWrap? It only has to last for two or three minutes, and at speeds of about 17,500 miles per hour. What's the big deal? I've seen this stuff wrap the same fruit cake for years ...

Reply to
J Strickland

The foam insulation on the tank seems to have stayed on except for the areas they did not attend to after the Columbia. They will fix those areas now too. It's quite a job. Did you see the launch and the video on the way up of the tank and shuttle which showed the foam coming off? Quite impressive and very good Q video.

Reply to
Dbu.

From

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"Almost nine minutes after the shuttle is launched, the empty external tank separates from the orbiter at the edge of the Earth atmosphere. Its fiery debris falls into the remote areas of the ocean around 58 minutes after launch."

"Originally, the ET was covered with a layer of white protective paint, however after the first two test flights this largely cosmetic cover was abandoned to save weight."

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Reply to
Truckdude

Yep, good to see them back again. Just make sure all that hi-tech filler and bonding agents is replaced with JB Weld and expanding grip foam, nothing will fall off then.

Reply to
Sleeker GT Phwoar

Sounds to me like you have a good idea there. I nominate you to head up the space shuttle program from now on.

Reply to
badgolferman

Do they let foreigners that close to such secure environments?

Reply to
Sleeker GT Phwoar

Ah, you're a Brit. You're OK.

Reply to
HachiRoku

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