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Discovery's Dangling Gapfiller Removed by Hand
Cyclotron_Boy writes "According to the New Scientist and NASA TV, Discovery's gap-fillers were removed successfully by hand by astronaut Steve Robinson earlier today during the eva. They didn't even have to use the forceps or the makeshift hacksaw-blade tool."
The gap filler is primarily used to prevent the tiles from rattling around during liftoff. During re-entry, the 7000+ psi pressure on the bottom side of the shuttle keeps the tiles on -- and steady.
I'm the Devil the Windows users warned you about.
The idea was that this dangling material might focus heat onto those surrounding tiles like a blowtorch on re-entry. Intead of the heat being evenly distributed over the entire surface, that area might get super-hot and burn up the shuttle.
The fabric is to prevent the tiles from banging together on lift-off. From the gist of the article, it sounds like it doesn't matter for re-entry. I guess they'll find out the exciting way when they try to land.
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According to the article they are made of ceramic-coated fabric and serve as buffers so the tiles do not rattle together and get damaged. I would imagine that during liftoff the ride is a little bumpy. The article also says that the only reason they are doing this is they think that they may cause added heat due to friction during re-entry.
This was discussed in the previous article but the material is coated in a material that can withstand thousands of degrees of heat. It would not burn off. Even the smallest stray piece of material can cause disruption upon re-entry.
The gap filler is needed to keep the tiles from rattling on LIFTOFF. Once in space, we don't need it.
The reentry has very different pressures/angles - I believe the pressure of the reentry keeps the tiles from moving enough to bump each other too badly.
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So far no American accidents in space have been fatal. We've had one fire on the pad before liftoff, one explosion during liftoff, and one single-vehicle in-air collision on re-entry. No Americans have died while actually in space, unless I totally missed something.
There are currently 9 people on ISS, and except for the 2 assigned crewmen I don't believe any of them have the necessary seats for the Soyuz. So even if you wanted to use it only 1/3rd of the people could fit.
Fortunately protruding gap filler is a minor issue, because you just can't evacuate 9 people from ISS with the attached Soyuz.
You can bring a shuttle down under computer control.
You can go into final approach under computer contro.
But you can't land. No landing gear.
The only way to open the landing gear is with a manual control. AFAIK it's the *one* part of the shuttle with no connection to the computers. ISTR that they were afraid of a computer glitch deploying the landing gear prematurely - say on orbit. The landing gear can only be stowed by the ground crew. There is no "raise landing gear" switch on the shuttle. Actually, the landing gear mostly "fall" open by gravity - it's the act of unsealing the doors premature that would cause a Bad Day.
The living have better things to do than to continue hating the dead.
Rather than using tiles wouldn't it be better to use some sort of spray adhesive
The tiles are heat radiators, not adhesives. Perhaps you meant the filler? It's not an adhesive either. There has to be gaps between the tiles (because the skin and tiles don't have the same thermal expansion coefficient), but gaps can pose problems (they increase the likelyhood of tiles falling out, for one; they also tend to channel in extra heat during reentry). The fillers deal with both of these issues.
What actually attaches the tiles to the skin isn't the filler, or even an adhesive - it is a felt strain isolation pad. A simple adhesive would come loose under thermal expansion. The tiles are attached to the pad, which is in turn attached to the skin.
"It felt almost as good as stealing cars from grandma." -- Margaret Thatcher, probably.
Technically, both Challenger and Columbia were not in space. Challenger was well within the atmosphere during liftoff, and Columbia was about 40 miles (about 65km) up, well below the 100km mark.
However, the Russians did have 3 deaths in space, on one of the Soyuz/Salyut missions (my apologies to any Russians, I don't remember the specific mission number). Komarov on Soyuz 1 was probably not an in-space death as well -- his chute tangled, and I believe he died on impact, which is definitely not an in-space death.
So out of 18 known in-flight deaths (and I am not counting Apollo 1, that wasn't in-flight), only three were in space.
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
I'm pretty sure there are some in Lower orbits too. Polar orbits are lower, some sats in the Polar orbits are NOAA/POES and DMSP weather satellites, Landsat and SPOT (remote-sensing satellites). See http://noaasis.noaa.gov/NOAASIS/ml/genlsatl.html for more info. There are not really "weather" (as we think of it) sats but gather data that is useful in many areas not just meterology.
The problem with the O-ring in the SRB had nothing to do with the heat shield of the orbiter. Challenger could very well have had a completely pristine thermal protection system and would still have been destroyed.
The post you replied to is correct -- while there have been problems with tile damage in the past, dating back to the very first mission (although the problematic area was later covered with thermal blankets rather than tiles, so the problem can't recur) -- there have been no cases of severe orbiter damage in the past due to tile/RCC damage.
i am a soviet space shuttle
Appearently you have never noticed that the shuttle has to fly. A solid hunk of iron would be much stronger, but we don't have anything that could lift a solid chunk of iron of that size into space. Even if we did, a solid hunk of iron is not very useful in space, so we would compromise on something weaker anyway.
Don't forget that the laws of ecconomics play off of the law of physics. The heavier something is, the more energy it takes to get to orbital speed, which means more fuel is needed, which means bigger rockets, and/or less payload. Either choice is less cost effective, and taxpayers don't like that.
A related concern is the heavier something is, the more energy you have to get rid on re-entry. This adds into other engineering concerns, but I'm getting a headache thinking of it all now.
page 4 from this NASA PDF:_ tps.pdf
http://www.nasa.gov/centers/kennedy/pdf/91372main
Gaps and Gap Fillers The gaps between the tiles, which range from 0.028 inch to 0.200 inch are necessary for two important reasons. The first reason concerns the difference in thermal expansion properties between the tiles and the orbiter airframe. When in orbit, the external temperature fluctuates by as much as 400 degrees F. The tiles contract much less than the airframe, due to differences in the thermal expansion; thus, the gaps are required to accommodate the difference. During reentry the gap dimensions are also critical. As the orbiter descends through the ever-thickening atmosphere, pressure gradients cause the plasma surrounding the orbiter to flow. If the gaps are too large, hot gases can flow through the gaps and can cause damage to the backup surface seals (filler bar). Gap fillers are used extensively to control the gap dimensions between the individual tiles in many areas of the orbiter and in some areas to provide mechanical 'padding' between the tiles.
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