Retiring the Shuttle ASAP - How do we do it?

Ad Astra · 2004-11-16 11:54:18

Our favorite curmudgeon is back!

It had been a while since Jeff Bell has written for SpaceDaily. He comes back with a few witty lines, such as calling the Nuclear Regulatory Committee "Girly Men."

Martian Republic · 2004-11-16 13:31:04

Could a separately launched Progress meet up with a separately launched US module, launched by an EELV?
Remember, try not to use anything that dosen't exsist, which means no Shuttle C plans. We need to figure out a way to free up funds for an SDV first.
I'm not sure what is the correct answer, we have many problems now but I hope NASA can go forward agian and do good

I suppose that it would depend on what we want to do next in space and how much we want to spend. That will pretty much dictate what we do or don't do or could do in space. But, with the current budget we could do more of the same or clear the board and maybe do a new manned Lunar Landing and/or possibly Mars landing strung out over a ten to fifteen year time frame, but it would be primarily a Foot and Flag program though and not a whole lot more. We also might be able to do a whole lot more unmanned programs and keep a limited manned program going on a shoe string. Unless we can expand the NASA budget several times what it is now, that is about all that we will be able to do.

Larry,

SpaceNut · 2004-11-17 09:14:33

The trouble with any off the shelf unit is two fold in that they do not have the heavy lift requirement of the future and they are not man rated or capable at this time.

SpaceNut · 2004-11-18 12:04:01

NASA's bid to fly shuttle runs into budget reality in Congress

Lawmakers this week are struggling to find enough money to safely return the space shuttle to flight while still meeting President Bush's demand to pay for longer-term endeavors that could lead to a mission to Mars.
NASA's backers on Capitol Hill have been fighting for months to secure all $16.2 billion that the Bush administration requested for the space agency, or at least enough money to keep the shuttle program in good shape.
Congressional aides said this week that lawmakers are hoping to secure at least $15.9 billion for NASA in a giant spending package for 2005.

White House draws line on NASA's 2005 budget Bush vows veto for plans with too much or too little

BUDGET BATTLE
Congress and the White House have different opinions about funding NASA in the 2005 fiscal year.
• President: $16.2 billion request
• House: $15.1 billion proposal
• Senate: $16.4 billion, including $800 million in emergency funding

Their plan called for using $500 million in emergency funds for the shuttle program's "return-to-flight" needs and $300 million to boost efforts to launch a mission to refurbish the Hubble Space Telescope.

Yang Liwei Rocket · 2005-07-17 13:39:36

U.S. Sen. Kay Bailey Hutchison, R-Texas, who chairs the Subcommittee on Science and Space, said she believes Congress will provide the money needed to keep the shuttle running safely until its successor is developed. "I think the key is not whether they are getting too old, but whether they are maintaining them properly," she said.

http://www.azcentral.com/news/articles/ … tle17.html

Aging space shuttle’s doom seems to be in the stars

Setbacks, risks due to old technology make end seem near

CAPE CANAVERAL, Fla. -- Maybe NASA’s managers still view the shuttle as the Cadillac of space technology, but they sometimes make it sound as if it were a cranky old Ford with a few too many miles on it.

dicktice · 2005-08-03 17:37:41

If the Space Shuttle's external fuel tank's foam is the main culprit threatening completion of the ISS by 2010, how about reconsidering the following? Remember the first launch, with the tank painted/coated white? The reason given for not continuing to launch with a white tank was to save weight. The insulating foam goes on white and oxidizes to rust colour, as I understand it, with time and exposure to air.
Now I ask any of you who may be concerned: What if the white (whatever it was) coating could have prevented the pieces of foam from breaking away from the tank, eliminating the unpredictable striikes and possible damage to the orbiter's reentry-heat protection tiles?

GCNRevenger · 2005-08-03 18:57:22

It wouldn't have, that paint layer was quite thin.

Holding the foam on would require a heavy layer (think pickup truck bed liner) or a netting to hold on loosend foam.

SpaceNut · 2005-08-03 20:37:10

Space Shuttle external tank

The first two external tanks, used in STS-1 and STS-2, were painted white. As a weight-saving measure, Lockheed Martin ceased painting the external tanks beginning with STS-3, leaving only the clear primer over the now-trademark rust-colored insulation, saving approximately 1,000 pounds (0.5 t) of weight.

Not all that much of a savings.

GCNRevenger · 2005-08-03 21:21:07

Considering that is 2% of the total Shuttle payload, it was an obvious improvement.

Commodore · 2005-08-03 21:47:08

Is there any reason they can't insulate the individual LOX and LH tanks within the ET, instead of outside of the whole thing?

That way if anything falls off, it doesn't go far, and definately doesn't hit the Shuttle.

John Creighton · 2005-08-03 22:22:57

Is there any reason they can't insulate the individual LOX and LH tanks within the ET, instead of outside of the whole thing?
That way if anything falls off, it doesn't go far, and definately doesn't hit the Shuttle.

I’m wondering for a sec here, how thick is the tank? Could you take half the material that makes up the tank walls for the inside of the tank, half the material for the outside and have the foam sandwidged between the two layers glued on one side to the inside wall of the tank and the other side to the outside wall of the tank. This way the foam all of a sudden adds to the structural strength of the tank and cannot fall off the tank. Moreover, such a composite structure can support a greater moment and makes it easier to build an even larger tank if a larger tank is ever needed.

GCNRevenger · 2005-08-03 23:12:37

Within the ET? The Hydrogen and Oxygen tanks aren't inside the tank, they are the tank. There is no outter, secondary tank wall; the only think between the foam and the fuel is one layer of metal just enough to hold the fuel under the stresses of launch.

Look, poeple... this needs to be a QUICK fix, NASA does not have alot of time here, and every day that Atlantis is not go for flight is another day that NASA just bleeds credibility. Redesigning the way the tank is built from is not happening, the current design plus or minus foam formulation, a mesh/coating wrapper, and how/where the foam is applied is set in stone.

John Creighton · 2005-08-03 23:25:18

Within the ET? The Hydrogen and Oxygen tanks aren't inside the tank, they are the tank. There is no outter, secondary tank wall; the only think between the foam and the fuel is one layer of metal just enough to hold the fuel under the stresses of launch.
Look, poeple... this needs to be a QUICK fix, NASA does not have alot of time here, and every day that Atlantis is not go for flight is another day that NASA just bleeds credibility. Redesigning the way the tank is built from is not happening, the current design plus or minus foam formulation, a mesh/coating wrapper, and how/where the foam is applied is set in stone.

I know the tank doesn’t have two walls but it would seem a structurally more sound way to make a tank. Perhaps it involves too much of a redesign for the shuttle (not sure how long it takes to build a take or modify the factory equipment). However, better engineering alternatives are worth discussing. For instance if the tank had a sandwich structure then the foam issue could not be used as an argument against shuttle c.

Grypd · 2005-08-04 08:34:43

So if it has to be a quick fix to a problem that just does not seem to be going away then there really is left only the one choice.

A measure must be added to or on the foam to stop it falling off. This cannot be new spraying techniques or a new foam material as to develop and properly test would take too long in to short a window.

A simple statement the next question though is harder this measure must weigh as little as possible so as to reduce the weight loss to the shuttle. It also must be done quick.

A Solid metal skin on top of the foam is not going to happen it would be too heavy and even another coating of a solid material sprayed on would increase weight too much. This only leaves a form of netting to cover the shuttle.

so netting it must be

GCNRevenger · 2005-08-04 08:52:39

You introduce loads of problems though, as the foam is chilled the gasses trapped inside will contract and liquify, plus the foam itself will get terribly brittle. And this is what is holding the two halves of your tank together.

Ordinarily yes, a "better" solution would be to find a way not to have external foam at all or some other engineering solution, but not this time. Shuttle needs to fly again. Soon. NOW. A quick and simple fix is absolutely imperitive.

SpaceNut · 2005-08-04 10:45:52

If the problem with the foam is as others put it, size of bubbles and atmospheric pressure that is within them. I would say then a couple of steps could be taken one of which is to go back to a lower pressure airosol if feon can not be used and the other would be to spray the foam within a near vacumn in order to trap less gas pressure within each bubble or is this caused by the airosol. ???

GCNRevenger · 2005-08-04 15:47:04

Even with switching back to the old foam, I still bet that there is some shedding, which needs to be stopped or at least some non-foam mechanism employed to limit fragment size.

Blowing the foam in a vacuum would be very difficult, and might make the bubbles too big. It would also require reformulating the foam with different amounts of freon.

SpaceNut · 2005-08-05 05:51:35

One of the draw backs for smaller cells is that more foam is applied to cover the same thickness. Which would take away from the launch payload cpacity.

GCNRevenger · 2005-08-05 07:17:25

The question isn't the thickness of the foam as much as its thermal conductivity; smaller cells may not mean signifigantly increased conductivity, since you are still getting a similar number of air/foam interfaces that the warm Florida sun and heat has to fight its way through.

dicktice · 2005-08-05 11:12:24

From the last few posts, re. painting/coating the ET foam ...

[Quotes]

It wouldn't have [prevented the foam to come off], that paint layer was quite thin.

Holding the foam on would require a heavy layer (think pickup truck bed liner) or a netting to hold on loosend foam.

The first two external tanks, used in STS-1 and STS-2, were painted white. As a weight-saving measure, Lockheed Martin ceased painting the external tanks beginning with STS-3, leaving only the clear primer over the now-trademark rust-colored insulation, saving approximately 1,000 pounds (0.5 t) of weight.

Not all that much of a savings.

Considering that is 2% of the total Shuttle payload, it was an obvious improvement [not to paint the ET white].

[End quotes]

... here are some counter-arguments:

Was any foam separation noted during the first white ET two launches (I thought it was only the first), or was it just dumb luck?

If, in fact, a sprayed-on coating of suitable thickness could be shown to prevent any loosened foam from falling from the ET during launch, thereby eliminating the possibility of the orbiter tiles being damaged in that way--what thickness would be needed, and how much lower down on the ET would it be need to be applied so as not to jeopardize the orbiter ... only to below the wing leading edges, for example?

A 1000 pound reduction in payload capacity, when the only other alternative is NOT to launch for fear of falling-foam pieces possibly damaging the orbiter tiles, would be a small price to pay in order to complete the ISS as specified, by 2010.

How many crew are required just to fly the Orbiter up to LEO? Could two or three crew, together with all their personal gear, not be eliminated, for a total of 1000 pounds or more, or whatever amount of coating, noted above, might weigh at launch? After all, up to five additional crew could already to be aboard the ISS (via Soyuz TMA) and trained to assist in the work required when they dock. Afterewards, the orbiter could then be usefully employed to transport a couple or more of them to The Cape.

SpaceNut · 2005-08-05 11:39:02

How about painting only the side that faces towards the orbiter. That still cuts the weight saved in half to only 500 but thats better than nothing.

GCNRevenger · 2005-08-05 11:57:39

Of course the layer or netting would only be applied to the orbiter's 40-50% of the tank, and preferably down all the way to near the tail ramp that guards the engine nozzles from reentry gasses. Reduced possibility of damage to a minimum.

As far as STS-1 & 2, how would they have known that foam fell off the tank? No cameras were mounted on it nor the orbiter which could have seen any detach, and the crews did not take superhigh resolution pictures of the tank after seperation, which required a quick maneuver and coordination between the crew of Discovery. I don't think that it was seriously considerd a threat, and NASA expected Shuttle's heat shield to be strong enough... and probobly worried more about the early-model SSMEs blowing up.

Exactly my feeling... if the foam shield subtracts 1,000 or 2,000 or 5,000lbs from the orbiters' payload, thats just too bad, they need to find a way to get the payload from someplace else. Shuttle has flown with a crew of five before if memory serves, but Discovery needed all seven to do all the repair work on ISS in addition to Shuttle repairs and repair training.

dicktice · 2005-08-05 17:42:05

I'm in total agreement with the last post. Now, with regard to the above-mentioned spur of the moment, Dubya-simple way to prevent foam chunks from falling onto the orbiter ... will NASA even consider such an expediant? I sure would like to hear their reaction, just to know it's been considered along with the many other suggestions we've been posting. Do I hear insane laugher in the wings?

RobS · 2005-08-05 21:11:48

You can't blow the foam's bubbles in a low pressure environment or a partial vacuum because when the tank is taken out of the chamber, the higher atmospheric pressure would crush the bubbles.

-- RobS

GCNRevenger · 2005-08-05 21:36:37

I'm in total agreement with the last post. Now, with regard to the above-mentioned spur of the moment, Dubya-simple way to prevent foam chunks from falling onto the orbiter ... will NASA even consider such an expediant? I sure would like to hear their reaction, just to know it's been considered along with the many other suggestions we've been posting. Do I hear insane laugher in the wings?

Nope, it sounds like NASA is just going to rip off the PAL ramps, or even just tell the Michoud people to be "extra careful," and call it good.

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#51 2004-11-16 11:54:18

Re: Retiring the Shuttle ASAP - How do we do it?

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