Feb 28 2006
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16 pieces of foam fell off Discovery
NASA plans on launching 3 Shuttles this year (the first one is scheduled for May), so let’s hope they get this fixed ASAP.
Isn’t one problem with the foam, is that they switched to a more environmentally friendly version, that has the side effect of being dangerous?
I thought I read an actual NASA report on that, but I can’t seem to find it now.
Hate to say it, time to retire the shuttle. Way to expensive and rockets could save millions per launch.
Noble experiment though.
I seem to remember the very first shuttles having a white outer shell on the fuel tank that probably covered the foam (and prevented this). I’m assuming they removed it for weight reasons. Anyone else remember this?
Ya lose 16 pieces / and whaddya get / another year pushed back /and deeper in debt
(Apologies to The Platters)
“How would Oscar Wilde put it? To lose one shuttle is a misfortune; to lose two seems more like carelessness.”
– Hugo Drax, Moonraker
Here is the NASA answer to the external tank paint question:
http://www.nasa.gov/returntoflight/main/email_responses.html
Kevin, that was originaly from Tennessee Ernie Ford (16 Tons).
I too remember a report that the foam on the external fuel tank was changed out to a type that was environmentally friendly but more prone to breaking off in flight.
Let me start this rant with a statement of love: I love the space program, and the very idea that we are exploring many corners of the cosmos. But as far as the shuttle goes, well, I for one have had enough. This ‘noble experiment’ has cost far too much (how many other mission directives have been waylayed for our ‘glorious return to flight?) and had negligible outcome…and more delays, cost overruns, and more stupid problems that were problems identified more than 20 years ago!
Retire the shuttle fleet, reconfigure the existing facilities for the cev , pay the Russians whatever they want to continue(!) ferrying our astronauts to and from the research lab in LEO, and let’s cut our losses on this misguided adventure. As for ISS, let’s call it done, and de-obviate the need for further shuttle missions.
I wonder if a Soyuz could be rigged for docking with/servicing HST?
I for one still despise Richard Nixon (and his advisors) for advising thias change in direction for our human spaceflight program. EGADS!
You guys in Star City rock! Keep up the good work.
Jeff- the external tanks used to be painted white, until someone realized the paint weighed about 600 lbs, and not painting the tanks meant a lighter launch vehicle and/or more payload capability.
“I seem to remember the very first shuttles having a white outer shell on the fuel tank that probably covered the foam (and prevented this). I’m assuming they removed it for weight reasons. Anyone else remember this?”
That was white paint.
Not painting the tank saved 300 Kg.
Anybody know whether NASA has studied the possibility that painting the tank would hold the foam together?
You’d need a paint that has a tensile strength. Epoxy paint?
I’m not sure I care all that much about the expense.
The danger involved sucks, but is largely known and accepted.
What I do NOT like about the shuttle, is it is a fraking terrible implementation of a great original idea. It is the prince witout his cloths. We all sit and pretend to awe and respect… when really we are all going ‘Yuck… what a stupid joke’.
THEN we see again the price tag, and the cost in lives. I’m just curious why more people are not mad as hell, like me.
u had a bad day, u had a bad decade…was wondering, before they actually discovered the foams falling of thing, it did fall of for all the other missions right? so did they like ignore it or what?
and and….why is soyuz doing much much better after a few hundreds launches?
The shuttle is built right at the edge of feasible technology. The tiles which protect them upon reentry need to have some amazing properties, but the only way we know how to make them, makes them fragile. The need to transport the SRBs from the manufacturing plant to the launch site means they have to be in sections and then assembled at the site. Thus, o-rings to try to seal the inevitable gaps between the pieces.
We can build just as good a capsule as the Soyuz capsule. A capsule on a booster is not technology on the edge of feasibility.
But, I probably agree that this technology is just too costly, unreliable and uncapable unough that it should be scrapped.
One of my grandmothers had her hair piled up half a meter (not unlike Marge Simpson, even down to the colour!) and she used hairspray by the bucket load. I never saw any hair or foam fall off her head (there must have been foam in there, it couldn’t all have been hair, could it?). So maybe the paint job did do some good on the shuttle tank.
ruidh says:
We can build just as good a capsule as the Soyuz capsule. A capsule on a booster is not technology on the edge of feasibility.
And let’s not forget, the Russians are working on developing a space vehicle to replace Soyuz–so they’re not entirely satisfied with it themselves.
This talk about Shuttle/Soyuz/CEV brings to mind something I’ve been wondering–do we know what this CEV is supposed to be(come)? Will it be an Apollo-like capsule, a reusable shuttle-type vehicle (maybe a piggybacked spaceplane with a shuttlecock like SpaceShipOne, my favorite idea), or something else altogether?
Arthur C. Clarke always said we’ll develop the space elevator as soon as people can stop laughing at it. I’d like to think we just moved one small step closer.
Ken Said:
>I wonder if a Soyuz could be rigged for docking with/servicing HST?
Not very likely. The Shuttle provides a couple of important features for crew servicing of the HST besides just the crew. First, it has that nifty payload bay that allows carrying the large (phone booth sized) boxes that are replaced inside the HST. Second, it provides a work platform that anchors the HST to the vehicle with crew and those large boxes. Then there’s that handy robotic arm (RMS) that allows the crew to move said large boxes of electronics around and in and out of the HST without breaking them or the crew. (Yeah, everything’s “weightless”, but they aren’t massless, so inertia still bites). There’s also a large pile of tools necessary for the crew to do any decent work. Those tools are cumbersome to strap on to the crew themselves and then try to crawl around. The RMS has a work platform that can be attached that can carry and store extra tools.
And also, the Soyuz docking system is worthless for HST, because HST doesn’t have a docking system. The Shuttle captures HST using the robotic grapple fixture and then attaches it to the HST work platform in the Payload Bay so the two stay together. Conceivably, a docking system could be designed and built to allow Soyuz to mount to the HST, but it currently doesn’t exist. And once you get there, you don’t have (1) the Payloads to replace the ORUs in HST, so there’s no point servicing it if you don’t have the parts to fix it; and (2) The robotic arm to help move those parts and crew members around, so it’s nearly impossible to do the servicing.
Gp Said:
>was wondering, before they actually discovered the foams falling of thing, it did fall of for all the other missions right? so did they like ignore it or what?
Foam shedding has been a consistent problem with the External Tank. They’ve noted the problem, called “popcorning”, before. The foam installation process can create small pockets or voids, which allow pressure build up from temperature and pressure changes, which puts enough stress in the foam to cause it to break and have pieces fall off. The shuttle was designed to withstand a certain amount of damage to the tiles precisely because they didn’t think they could eliminate all possible sources of damage. However, the foam shedding was unexpected and they never really solved it. They sort of monitored the problem and assumed that as long as the shedding was in a certain range, it would be okay. Columbia showed their assumptions weren’t valid and allowing the ongoing problem without understanding the true cause wasn’t a good practice because they hadn’t quantified the possible damage amount, only the list of what had happened so far. So it wasn’t entirely ignoring it, but it wasn’t fully addressing the problem, either.
Gp Said:
>and and….why is soyuz doing much much better after a few hundreds launches?
Soyuz is a completely expended vehicle - 1 time use. Each Soyuz capsule is built from scratch, like the old Mercury, Gemini, and Apollo vehicles.
Leon Said:
>This talk about Shuttle/Soyuz/CEV brings to mind something I’ve been wondering–do we know what this CEV is supposed to be(come)? Will it be an Apollo-like capsule, a reusable shuttle-type vehicle (maybe a piggybacked spaceplane with a shuttlecock like SpaceShipOne, my favorite idea), or something else altogether?
The new CEV was decided to be a combination of Shuttle and Apollo type technology. The spacecraft itself will be an expendable crew vehicle sort of like an up-scale Apollo command capsule - seats up to six I think. It uses the ablative heat shield, not the shuttle tile. The launch vehicle will consist of a solid rocket booster built off Shuttle SRB tech.
Your grandmother probably never travelled at 17,000 miles per hour.
“Your grandmother probably never travelled at 17,000 miles per hour.”
No, you got me there, how silly of me. She did however write all of The Beatles’s songs.
Irishman said:
The new CEV was decided to be a combination of Shuttle and Apollo type technology. The spacecraft itself will be an expendable crew vehicle sort of like an up-scale Apollo command capsule - seats up to six I think. It uses the ablative heat shield, not the shuttle tile. The launch vehicle will consist of a solid rocket booster built off Shuttle SRB tech.
Ew, I’m not sure I like that. The SRBs were a shortcut from liquid-propelled boosters in the first place, to save money. Sounds to me like we might as well go back to putting an old-fashioned capsule on a booster.
You know, I recall there was an effort there to reuse capsules for a while. If I remember right, a Blue Gemini (the military version) flew, returned to earth and was refurbished, then flew again without incident. It was an unmanned test, but why couldn’t we have a CEV that’s refurbished with a new heat shield between launches? And use LOX to launch it for Pete’s sake!
A blue Gemini…don’t remember that..was it just a test?
Space Elevator…pure science fiction and quite possibly a boondoggle even worse than the shuttle!:)
Nuclear Fusion? Hey, I would like to see this happen but every time you ask it’s always another 10 years down the road…
When they finally get a real reactor going for say 5 minutes or more then that might be feasible…we are a heck of a long way from that though.
The link above talking about painting the tank suggests covering the foam with a net, etc. But my question is why wouldn’t you embedd the netting IN the foam.
It seems to me that this is no different than putting drywall tape in the seams of new sheetrock. If you don’t, any significant vibration and you get chunks of dried mud tumbling out. Embed a binder and it’s far less likely to crack/break off.
As for the netting becoming a debris hazard, it would be embedded with the rest of the tank and so it seems like it wouldn’t be a major issue.
Also, with some testing, a good size for the mesh could be determined that would limit the size of foam chunks since the borders of the mesh would limit the size.
P. Edward Murray Says:
A blue Gemini…don’t remember that..was it just a test?
I’m having trouble finding the article I originally read, but here’s a reference:
http://whizzospace.com/museum/museum3.htm
Another Blue Gemini reference (actually a Wikipedia entry about the program):
http://encyclopedia.thefreedictionary.com/Blue+Gemini
There doesn’t seem to be anything in those links about the Blue Gemini program intending to reuse the capsules, only that they took an existing capsule and reflew it once to gather data.
P. Edward Murray, depending upon your concept of a space elevator. I think the NASA feasibility study gave some pretty good results on the reasonableness to developing the technology. There are some unanswered questions and some design challenges that require more study for a solid answer, but some of the necessary technology is already being developed commercially for other applications, specifically the carbon nanotube fiber tethers.
Irishman Says:
There doesn’t seem to be anything in those links about the Blue Gemini program intending to reuse the capsules, only that they took an existing capsule and reflew it once to gather data.
Yeah, my memory was pretty hazy about what I read. I think what I had carried away from the article was that reusing a capsule had been done once, and that the Air Force concluded it could probably be done repeatedly. Seems to me like a reasonable idea for the CEV.
I think this will be the last shuttle flight. And frankly good riddance. Hopefully no more people die, but the shuttle is fatally flawed. The foam was never really the problem, the issue is putting the shuttle on the side of the propulsion system. This fact makes it susceptible to getting hit by debris as well as a more difficult system to transfer thrust to the vehicle. I’m glad that we have a new focus that will get us out of earth orbit. I suspect the CEV will get cancelled by democrats at some point, though eventually it (the CEV not its cancellation) should save money. The worst is that robotic missions are getting cut, which is absurd.
The term “Yikes!” understates the problem. NASA is now planning to cannibalize one of the three remaining Shuttles after only a few flights. This plan may expose the ISS program to the possibility of failure induced by even a simple ground accident which severely damages a shuttle, for example. Sure that’s not *very* likely, but do we know how likely it really is? Of course, the risk of an in-flight loss of another Shuttle will remain fairly high even with the work of the last year. Furthermore, NASA is now planning to rob $3 billion dollars from science programs over the next three years to pay for Shuttle cost overruns. The overruns keep coming.
I’m a NASA fanboy, and I think that humanity needs to get into space and do stuff like build permanent space habitats, moon bases, expore the planets and whatever else we can dream up. I think the benefits will pay of a million fold if we do. But doing those things requires inexpensive and reliable access to space. We don’t have it, and we’re not planning to get it anytime soon.
NASA should cancel the Space Shuttle program immediately. If the astronauts are willing to risk it, one more flight to Hubble, then call it quits.
Let’s get to work on the real problem — reliable access to space will never happen if we don’t start working on it. Let’s start now.
/gary
http://antibogon.org/blog/
[…] Epiblog: I learned this morning that 16 Chunks of Foam Fell Off Shuttle Tank Last July. This is discussed at the Bad Astronomy blog, too. […]
How about this talk to the winner of the X-prize. His ship is reusable and needs no heat shield. It’s made out of glue,fabric, and a metal frame. Out to low orbit twice. With less cost than the shuttle NASA could use this. (a larger ship of coarse) That does not make space travel safe it is dangerous. 14 people have died with the shuttle. More have died with the developement and use of the commercial jets. they thought the jets were safe. The crews of the shuttle know the risk and there is a lot of it. checking the tile before reentry is a good idea it may save lives.The foam may be better with nylon strands mixed in it. we can not stop the iss the world needs us to keep our side of the project. We told them we would do it so lets not stop now
It didn’t get to orbit, it was well below orbital speeds. That difference means everything. Coming back from orbit you are mocing much faster, and need to bleed that speed off. Ram pressure through the atmosphere is the easiest way to do it, and for that you need heat resistance.
That makes sense! I wondered why SpaceShipOne didn’t need a heat shield of some sort. I figured part of it was because it was a suborbital flight, but I wondered also if its shuttlecock system helped substantially in reducing the amount of heat generated by air compression on its way down.
SpaceShip One hovered over its launch point at ZERO speed. It’s maximum reentry speed was just over Mach 3, around 1,000 meters/sec. Orbital velocity is just over 7,500 meters per second. That’s a big difference in energy requirements. They’ll figure it out, though. If I were Rutan I’d lob a SpaceShip One to Utah, then another to Texas, then Florida, finally over the pond to Europe or Africa. Maybe team with FedEx for same-day delivery to Europe. Finally I’d work up to orbiting Earth. Good luck!
SpaceShip One exterior temperature was no higher than 1000 F, a simple ablative insulation was used to protect the skin, and only for about 1 minute. Shuttle and Soyuz see +3000 F for up to 10 minutes. CEV lunar return much higher temps an order of magnitude greater heating rates. Remember energy goes as velocity squared, and heating (power) as velocity cubed. So orbital entry is a huge leap from SpaceShip One’s suborbital entry. And lunar entry is a big step up from orbital entry. And Mars return is really way out there.