Proposal Modify Shuttle Fuel Tank

[Chris Walters]

Unsolicited Proposal To Modify Shuttle External Fuel Tank​

Addressed Too:
NASA HEADQUARTERS
Attn: Sandy Russo
Code 210.H
Goddard Space Flight Center
Greenbelt, MD 20771
Sandra.R.Russo@nasa.gov
Office of Space Flight
Space Shuttle

Abstract, Introduction Project Description​

This unsolicited proposal asks as a research paper if construction changes
in the Space Shuttle External Fuel tank could resolve chronic foam problems
by:

1. Foam insulation for external fuel tank to be created using single
common injection mold with a light weight metal matrix for support designed
to be pulled in place over the fuel tank.

2. A second variation would involve cutting the prefabricated foam
unit in half vertically and installing it by snapping it shut over the fuel tank
and locking it later.

3. A light metal matrix outside the complete foam unit it used to
support the outer skin of silicone seal which like the material used
commonly on roofs is sprayed on.

4. The proposed change created an inner foam protection surrounded
by a lightweight; waterproof; and resistant to ice silicone layer of silicone
seal which is extremely adhesive and I have found over 30 years
actually very difficult to remove once it dries.

5. If NASA or Lockheed Martin are interested in this concept I would
suggest a small model of the tank be constructed and tested in the windtunnel to approximate shuttle launch conditions.

6. The ultimate purpose of this research proposal is to add structural
support to the foam and create a highly durable silicone seal around the entire
structure to prevent materials flying off the external fuel tank

Management Approach Personnel, Costs, and Facilities​

If the research idea herein was in favor the management NASA and Lockheed Martin would have to secure outside contractors to create the special molds;
metal support skeletons; and silicone spraying crews all of which are
commonly available throughout the United States. If your organizations
require me to act as consultant I would require transportation to your
offices on Greyhound; motel accomdations; food...

8. Other Matters​

If NASA is willing there are some other modifications of possible modifications of Space Shuttle tile systems which might expand the life and use of the shuttle systems which could be introducted later. I have an extensive online resume which parties interested in knowing more about my backgound can consult

http://www.geocities.com/certvolunteer

By Chris Walters
c/o 7335 Ritchie Dr
Austin, TX 78724
chrissaidthanks2002@yahoo.com

 

[Clausius2]

Chris, do you work for Nasa or so?

You seem to be very afraid about this stuff.

Ok, keep on trying it. Maybe you find the solution for Nasa headaches.

 

[Chris Walters]

From: "hq-public-inquiries"
hq-public-inquiries@nasa.gov
To: "'Chris W'" <chrissaidthanks2002@yahoo.com>
Subject: RE: UNSOLICITED PROPOSAL
Date: Fri, 29 Jul 2005 17:45:48 -0400

Dear Mr. Walters:

Thank you for your inquiry to NASA.

Under Federal regulation, NASA is authorized to accept technical proposals for evaluation only under one of two conditions: a proposal must either be (1) submitted in response to a formal competitive solicitation; or (2) presented as an unsolicited proposal. The procedure for submitting an unsolicited proposal is described in a NASA guidebook located at http://ec.msfc.nasa.gov/hq/library/unSol-Prop.html. The concept you describe is not structured as an unsolicited proposal as defined by the guidebook. Therefore, as submitted, it cannot be accepted for review. These rules are primarily intended to protect patent rights and copyright privileges of inventors.

Also, included in the above Web site are the respective NASA Centers and their particular technical areas of responsibility under the section entitled, “NASA Research areas and addresses for submission.” Perhaps you can address your questions directly to the respective NASA Center for an expedited response. After you review that information, should you continue to believe that your proposal would be more appropriately aligned with an area of research associated with a particular NASA Center, please forward a valid unsolicited proposal directly to that Center. You are strongly encouraged to follow the instructions as outlined in the “Guidance for the Preparations and Submission of Unsolicited Proposals,” Web site so that NASA Center personnel can process and fairly review your proposal.

NASA hopes that this information will be helpful to you as you pursue your goals. Again, thank you for your letter and interest in NASA.




Public Communications Management Office
NASA Office of Public Affairs

 

[Q_Goest]

Chris, I'm not meaning to be antagonistic at all. In fact, I wish you well. You seem to have an entrepeneurial spirit, and that's good. I've tried doing things like you're doing at a young age that seemed like the thing to do at the time, only to realize later in life how far off base I was in even considering what I had thought.

Anyway, here's a few thoughts:
- No consultant is going to ride on Greyhound all the way from Texas, nor even suggest such a silly detail. If you get a consulting position with any firm, NASA or otherwise, you'll set up the conditions at that time, not before. Besides which, NASA doesn't make the tank, nor do the engineering on it. They may help, but that's the responsibility of a subcontractor.
- The idea of reinforcing the tiles is fine, but as Astronuc has pointed out, the thermal expansion of the tiles needs to be accommodated. And that's just the start.

One concern regards solidified or liquified air at the tank wall. At a temperature of -420, which the tank wall is at, anything but helium and neon is cold enough to solidify. As you go out away from the wall through the tile, you'd see some point that has a temperature above -340, which is the temperature at which nitrogen solidifies (aprox). At that point, air changes to a liquid. It isn't till you get to -320 to -280 that you will get gasseous air. Oxygen liquifies at a higher temperature than nitrogen, so you can get a concentration of liquified oxygen at this level. This is a concern because of the flamability of an oxygen rich atmosphere in a potentially flammable foam insulation.

That assumes you have a temperature gradient with air in it. In reality, there is very little air in this vicinity, though there is some, mostly between the tiles I'd suspect. Instead, you have whatever gas is inside the closed cells of the foam. I'm assuming they have closed cell, I think that's a reasonable assumption. Whatever is in the closed cell is going to solidify in a similar manor though. The only difference will be that the gas is likely to change phase at a higher temperature, as opposed to a lower. If you made a foam with a vacuum inside the cells, and were able to prevent air from ingressing through the molecular structure (which is nearly impossible) then that might be the best solution.

One of the problems with the hydrogen tank tiles is the rapid decompression. As the vehicle goes through the atmosphere, the atmospheric pressure drops rapidly. In so doing, any gas inside expands as a function of pressure. The main problem I've heard about is that cryogenic liquid air starts boiling rapidly, giving off gas. And any solid may even start to melt or subliminate. I'd guess the solid is the least of the concerns. The boiling liquid air is a serious threat. One concept that NASA has considered is to purge the entire insulation with helium, but that is very costly to say the least, and helium is a limited resource even more so than petroleum.

There's a lot that goes into the details. Simply covering up the entire surface with a vapor barrier and reinforcing it is just one consideration. There are numerous details to consider. Also, there are numerous other rockets which use hydrogen for a fuel, and how they do it has also been considered, I'm sure. If you have some ideas about how best to do this, why don't you throw them out for suggestion.

 

[Chris Walters]

Q-Goest: did you misread this article?

Hello Q_Goest: many thanks for your reply and input. I am
probally wrong but the shuttle tiles are only mentioned in
passing the topic of this article is possible changes to
the external fuel tank. The idea we are discussing here involves
sandwitching the external fuel tank foam between 2 layers
of silicone with an internal lightweight mesh of metal for
structural strenght. If I was asked to travel I don't ever
fly and always travel Greyhound (sometime Amtrack).

I have 20 years experience in consulting with government
in other fields and my work has lead to the creation of 5 or
6 federal statutes. As your comment suggest changes in NASA
or Lockheed Martin are unlikely becuase large organizations
don't like to change the way they operate and in fact
the "contractors" and NASA mistake have lead to 2 shuttle
disasters-another will end the program.

I'm still kind of new to Physics Forums and haven't figured out
how to delete my previous article" Modification of Space Shuttle Tiles?"
to avoid confusion. Thanks for the technical details
and input. Chris Walters

PS There is a fair article of the Space Shuttle External
Structure and function on line:

http://en.wikipedia.org/wiki/Space_Shuttle_external_tank#ET_thermal_protection_system

 

[Q_Goest]

Hey Chris, I share your concerns about the possible demise of the shuttle program. And I'd agree that Lockheed Martin and NASA are highly unlikely to seek outside assistance unless it comes with considerable credentials and of course, lots and lots of experience. Unfortunately, there really isn't a whole lot of experience outside of the aerospace industry.

I found a bit more information about it after doing a quick web search. Here, the article cites the liquid air entrapment problem I mentioned:

At the time of Columbia's destruction, NASA engineers believed a phenomenon known as cryopumping was responsible for foam shedding. When the external tank is fueled for launch, air trapped in voids in the insulation or near the skin of the tank can turn into a liquid. As the shuttle rockets away, aerodynamic heating can cause that trapped liquid to turn back into a gas. The pressure generated by that phase transition, it was believed, could blow overlying pieces of foam away from the tank.

The Columbia Accident Investigation Board concluded such cryopumping alone could not explain the separation of the suitcase-size chunk of debris that doomed Columbia. But Readdy said today additional testing shows a different type of cryopumping can, in fact, cause such shedding.
"We've found out that the bolts and the nuts being applied to actually construct the different areas of the tank ... before you put the insulation on, that any kind of gap in there might be an opportunity for liquid nitrogen or liquid air to form," he said. "And what happens is, during the ascent environment, when the shock waves form on the external tank, aerodynamic heating and friction occurs and as a result, even trapped air kind of expands."

The expansion of that trapped air "imparts a velocity to that particular piece that causes large pieces to come off and instead of (peeling) away from the tank, actually being pushed away from the tank due to that gas pressure behind it," Readdy said. "That is really the root cause we've been able to discover here.

Ref: CFD Review

One solution is to have a blanket of helium underneath the foam which was the solution used for the Centaur upper stage used with the Atlas I. They've switched to a "fixed foam" insulation which is similar to the present shuttle foam, though I don't know the exact differences or how that insulation fairs in comparison.

I saw somewhere that the Saturn rocket insulated from the inside of the tank. I've tried doing that for a cryogenic system that went down to -450, and it worked quite nicely, though I'll admit it was for helium gas and if it were a liquid there would be other issues to overcome, though certainly not insurmountable ones.

One problem with silicone is that it will get extremely hard and brittle at the temperature the liquid hydrogen is at. I believe the Centaur uses epoxy, and I believe they've tried others, but I don't think silicone was ever tried because it's an elastomer that will likely crack due to thermal stresses. Even the epoxy might crack, but it's a much better material.

Also, putting silicone on the outside may be problematic too. Aerodynamic heating during ascent results in very high temperatures and although silicone is a good high temperature elastomer, I suspect there will be issues, besides which it isn't impervious to air. The air will still get in. And of course there's the weight consideration.

Maybe if there was some way of sucking the air out of the insulation, or filling it with helium, or providing a low flow helium purge on it. I know they considered a very high flow helium purge before going back to flight, but it was such an enormous amount, it became prohibitive. That isn't to say that much helium is required, but it gives you an idea what has been considered.

 

[Chris Walters]

Process Flown STS #1 & 2

Addressed Too:NASA HEADQUARTERS
Attn: Sandy Russo
Code 210.H
Goddard Space Flight Center
Greenbelt, MD 20771
Sandra.R.Russo@nasa.gov
Office of Space Flight Space Shuttle


It appears that NASA already used and discared Fire Resistant
Latex flown in STS-1 and STS-2 as described in the Book
Space Shuttle by Dennis Jenkins (1996) Library Congress
#9694309. On page 242 Dennis describes the ET Thermal Protection
System to include ETC PR2488 & Ablatos MA 255 and SLA 220.
The Fire Retartant Laxtes was removed to save 545 lbs and
$15,000 of cost to external fuel tank.

I making an unsolicited bid proposal I didn't realize the
idea of using latex or other rubber composite protection over
the foam system was already tried. Chris Walters

cc
Media Reps Jan Wrather
(303) 971-5967
janet.wrather@lmco.com
Harry Wadsworth
(504) 257-0094
harry.wadsworth@lmco.com

 

[Q_Goest]

Interesting info. Interesting also about the cost being mentioned. The savings on the latex treatment may be tiny, but the savings of putting that many pounds of payload into orbit is huge. A pound of payload to Geo used to be about $10,000 per pound. Not sure if that's come down much since 10 years ago, but I suspect it has. Anyway, the Shuttle isn't going to Geo of course, but I would guess it costs quite a bit to put 545 pounds of payload up.

 

[Chris Walters]

Question Modification of Entire Shuttle Program

Question Modification of Space Shuttle System[/br]
Based on Improved Use of Existing Assets​

This is a generic idea which NASA refers to as an unsolicted bid to improve the use of existing space assets to extend the life of the space shuttle system and improve safety. It is believed the existing system could be reverse engineered to create a system which has fewer complexities and would be stastically less likely to fail:

#1 Replacement of Shuttle Outer Skin​

1. The shuttle would be stipped of it's various outer thermal tiles to the inner aluminum skin

2. A system of lightweight inner tiles would be place around the inner aluminum skin with an inner gasget of either silicone or other latex.

3. An out skin of possibly of titanium or other high tensile metal would form the shuttle outer skin.

4. We would need to create a small model to show the new configuration of outer skin of metal; inner layer of tiles; and inner layer of aluminium

#2 Revised Mission Profiles​

1. As the shuttle is basically a "space plane" it designed to spend most of it's time in orbit

2. When not in use the shuttle is docked on an oribital pivot or triangle with the other shuttles for maintence; fueling; and other aspects of mission preparation

3. Mission expendables are regularily lofted into orbit by what the Russians currently are experts at "big dumb rockets" which are reported to be magnitudes of order cheaper than shuttle launches and can easily include personnel and even science projects.

4. If the Russians are experts in "big dumb rockets" ask the space partners to use their expertise on this facet of the operations.

5. The shuttle would have to under go modifications to include docking devices on the wing tips; nose; under belly and probally under the tail to accommodate being moved by a remote space tractor.

6. The shuttle revised program requires few if any travels to Earth and has modifications to include refueling in space (details not explained here); ongoing maintence in space by a small resident crew.

#3 Use of Cocoon​

1. The Space Shuttle cocoon is an artifact which is lofted into orbit by "big dumb rockets" and designed to fit over the shuttle like a glove when it returns to earth.

2. The cocoon is metal shaped in the form of the front and sides of the shuttle covered with a extra heavy amount of thermal protection.

3. The space shuttle docks with the "cocoon" and attached by hard points in the nose; wing; and then then begins it decent

4. The cocoon is designed to take all the heat of reentry while permitting the shuttle inside to use it's front thrusters; rear engine; and wing slats to manuver

5. When the Shuttle has decended and slowed enough the cocoon is jetisoned by simply flying the shuttle upside down and backwards where air pressure will cause it to slip off

6. The space shuttle then lands as it would normally

#4 Discussion of Reverse Engineering​

It seems plausible that many of the design flaws in the current space shuttle system were created in the 1970's when engineers tried to incorporate too many new and untried technologies. Reverse engineering and revision of the space shuttle mission profile means the vehicles spend most of their time parked in space instead of the in the hangar. The Shuttle would be used primarily to fly only on missions in space instead of making endless trips too and from the Earth as a sort of low class ferry for shuttle crews.

 

[ray b]

ICE is the problem

simple solution
move the launch site to a low humid envroment
like a desert
as the problem ain't the foam
it is ICE the forms from the very humid air in FLA esp on a ocean coastal envroment
that hits the tiles and breaks them not just the foam

btw they have an other site vandenburg AFB in Cal in a dry lake bed

or they could move back to the original site in new mex that was a desert site white sands

------------------

 

[Chris Walters]

STS 1 & 2 already flew with special chemcial seals

Hello Danger & Ray: and thanks for your input. We learned that
the process of sealing the foam was already flown on
STS Missions #1 & #2 as cited further below.

Astronuc certainly did have an excellent idea of placing
stip heaters in a silicone or latex sealer around the
foam.

The Cocoon or anyother proposed system if it could be designed
and engineered would have to be tested in a wind tunnel on
a model before it could actually be installed on the larger
system. Consider Q-Goest previous estimates of $10,000
a pound to lift materials into orbit and then consider the
cost of lifting the shuttle into orbit 123 times. The
billions in costs savings of leaving it in orbit might
have paid for the costs of modifications and purchase of
several more shuttle.

I am somewhat new to physics forms and have made the
mistake of having 2 similar conversations going on at
the same time. Thanks again Danger-Chris


Addressed Too:NASA HEADQUARTERS
Attn: Sandy Russo
Code 210.H
Goddard Space Flight Center
Greenbelt, MD 20771
Sandra.R.Russo@nasa.gov
Office of Space Flight Space Shuttle


It appears that NASA already used and discared Fire Resistant
Latex flown in STS-1 and STS-2 as described in the Book
Space Shuttle by Dennis Jenkins (1996) Library Congress
#9694309. On page 242 Dennis describes the ET Thermal Protection
System to include ETC PR2488 & Ablatos MA 255 and SLA 220.
The Fire Retartant Laxtes was removed to save 545 lbs and
$15,000 of cost to external fuel tank.

I making an unsolicited bid proposal I didn't realize the
idea of using latex or other rubber composite protection over
the foam system was already tried. Chris Walters

cc
Media Reps Jan Wrather
(303) 971-5967
janet.wrather@lmco.com
Harry Wadsworth
(504) 257-0094
harry.wadsworth@lmco.com

 

[Astronuc]

Hah! They are seriously consider the mesh or netting - finally!

http://www.orlandosentinel.com/news/custom/space/orl-bk-shuttle081105,0,4333611.story?coll=orl-home-headlines

"We probably won't make the September launch window," said Bill Gerstenmaier, a senior NASA manager at Johnson Space Center in Houston.

He said NASA is looking at a number of potential fixes for the tank, including some measures that could be done rather simply. But others, such as re-designing the PAL ramp, may take longer. Gerstenmaier also said NASA is considering more creative solutions, such as putting netting over areas of the tank.

 

[Chris Walters]

Reply from Lockheed Martin

Hello Astronuc:

Thanks for your most recent reply. I got a nice reply from Lockheed Martin
which is shown below. Hope whatever
they try they test it on a model in a windtunnel
first.

I also considered your figure of $10,000 a pound
to life the 165,000 empty pounds of the shuttle
into orbit at a cost of $165 Million. This goes
back to the idea of enormous saving to leave
the shuttles parked in space and use "big
dumb rockets" to lift cargo into space as
much cheaper.


From: "Buddy Nelson" <buddynelson@mac.com> Add to Address Book
Subject: Re: Submit Unsolicited Bid External Fuel Tank-Research
Date: Tue, 2 Aug 2005 10:21:15 -0700
To: chrissaidthanks2002@yahoo.com
CC: "Michelle Brown" <michelle.a.brown@lmco.com>,
"Jan Wrather" <janet.wrather@lmco.com>,
mary.jo.polidore@lmco.com


Mr. Walters -- Thanks very much for your ideas on the shuttle
external tank.

As you know, despite the foam shedding at the PAL ramp and a couple
other areas of concern, Discovery actually suffered 80% fewer "dings"
than average during launch. Nevertheless, we are working closely with
NASA to address and fix those few areas of the tank that remain
problematic.

We appreciate your suggestions.



Buddy Nelson
Lockheed Martin Space Systems Company
Communications