What should NASA do NOW?

[drwayne]

Can't do it as currently configured. The shuttle only has power for a few weeks on-orbit operation, before the cryogenics that supply its fuel cells are gone. <br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[spayss]

"I SAID that the most probable course of action was that the shuttle would fly soon"<br /><br /> This has nothing to do with flame wars. Please substantiate why you (and almost no one else) thinks that the most probable course of action is that the Shuttle will fly soon.<br /><br /> What I've heard in science editorials, etc. is that the Shuttle is unlikely to ever fly again...let alone 'soon'. <br /><br /> How are you going to fix the foam issue 'soon' when it wasn't fixed in 2 and a half years? This was at the center of much of the Shuttle's delay to date. <br /><br /> This isn't a trivial matter. All of your ISS completion, full ISS crews, etc. depends on a reliable Shuttle...with a substantial number of flights before its retirement in 2010. <br /><br /> All of your predictions are based on the Shuttle getting off the ground according to planned schedules. Why do you see this happening when even NASA doesn't? The latest from NASA is that the Shuttle is grounded and will not be flying 'soon', if at all, again.

 

[skywalker01]

<<Did you read my suggestion?>><br /><br />About flying the Shuttle with a minimum crew and not changing the foam from what it is now?

 

[frodo1008]

OK, I stated that there were other options and levels of activity of the shuttle that could be used to carry out our obligations to the ISS. I know that there are some on these boards who believe that we (the US) should just abandon such obligations, and therefore make it easier to completely shut down the shuttle program itself. <br /><br />I have several objections to doing this. One is that we (the US taxpayers) have already paid for several billion (yes, I said billion) dollars worth of ISS equipment that has already been fabricated. It is just waiting at the Cape to be launched up to the ISS. As a taxpayer, I object to just wasting this equipment. I even have some thoughts on what to do in case of a complete shutdown of the shuttle. But that is for another post. I know that what you say about the importance of space to others such as the French is quite true.<br /><br /><br />However, I am not worried about the word of the French, or of any of the other partners in the ISS except that of the United States. I neither am a citizen of these other countries, nor do I live in these other countries. The United States is my country, and I am just old fashioned enough to want us to keep OUR word to others, whether others return the favor or not is up to them. Not only this, but I am just as certain as birth that if we let down our partners here, that others will use this (regardless of how important they may feel space really is) as an excuse to block other activities that the US may consider important. That is politics, and reality! Besides, I fully think that the information obtained from a completed ISS will prove to be quite valuable to the space programs of the future, and I would want the US to be able to fully participate without bad feelings and rancor from the other partners!! <br /><br />In other words let us make the assumption for the sake of this discussion that we will indeed make our obligations to the ISS. By the way just being late with our con

 

[drwayne]

"About flying the Shuttle with a minimum crew and not changing the foam from what it is now?"<br /><br />Yes sir.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[frodo1008]

Well I am quite surpirsed when taking your suggestion and looking over just the posts on this thread. It would seem that there are quite a lot of posters who think that not only will the shuttle fly again, but even fly again soon! I really did thing you might very well be correct and I was quite alone, but eveidently I am not!<br /><br />Thanks for the suggestion!<br /><br />Please look at my reply to RadarRedux, I specifically state a possibility that is more along the lines of your own here!

 

[cyrostir]

why havent they developed a heat resistant paint, to coat the shuttle under belly with?

 

[drwayne]

Why would you assume such a thing is possible? Remember, you are talking about 1000's of degrees, temperatures that even metals such as titanium have issues with.<br /><br />If you are going to insulate, then you have to have a material that can trap heat. This is going to be likely to be fairly low density material, such as the existing tiles. It will have to have a certain thickness to trap and hold heat away from the shuttle, which does not sound like a paint to me. More like a foam.<br /><br />On the other hand, ablators have a long track record of success. I don't see however how you are going to paint on an ablator.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[skywalker01]

A couple of thoughts come to mind.<br /><br />A big part of what makes the Shuttle valuable is its ability to carry additional crew to perform EVAs, or operate the arm, or operate the science equipment that is in the payload bay. So I guess the question here is, is the ISS far enough along that it and its crew are capable of performing these functions if the Shuttle was used as a delivery truck with only a pilot and co-pilot.<br />At a guess it would take a lot more Soyuz flights both for additional crew on the ISS and as lifeboats which then runs into the export restriction problem. But assuming that the political will exists to solve that problem then I suppose that could be made to work assuming the ISS is capable of supporting the larger crew and the larger number of Soyuz spacecraft docked there.<br /><br />The other thought that comes to mind is that I suspect that we would end up with three Space Shuttles stuck in orbit before the ISS is finished. The problems that would be caused by that, as well as the cost of their solution, would appear to make fixing the foam the easier more cost effective solution.<br />

 

[gawin]

here is a quick thought.<br /><br />what if they designed some sort of deflector "wing" for lack of a better term to cause the air flow that goes along the tank to deflect any debree away from the shuttle.<br /><br />This does have problems i know with wieght and dynamic loads but it should be possable to force the ariflow in such a way that debree is deflect away from the shuttle rather then just left to fall hap hazards and hope it doesnt hit anything vital.<br /><br />gawin

 

[spacefrak]

If only Shuttle could remain in space longer (power issue? Refueling..), it could be used as a assembly tool same way as presently. <br />Launch cargo; ISS componenets, supplies with commercial heavylauncher (or remaining orbiters..)and pick them aboard in orbit, bring them to ISS and deliver.. One orbiter in orbit all the time and rest doing the hauling remotecontrolled. <br />Use Sojuz to replace the crew (if they even want to come back once in a while..)<br />The crew would be in "real danger" only once: when returning from orbit in a Sojuz or two.

 

[drwayne]

"If only Shuttle could remain in space longer (power issue? Refueling..)"<br /><br />The capability does not currently exist. To develop it would cost quite a bit of money/time. I suspect you are better off with a purpose built solution.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

"The other thought that comes to mind is that I suspect that we would end up with three Space Shuttles stuck in orbit before the ISS is finished."<br /><br />Why would you suspect that? I specifically stated that we would ditch them - destructively. Doing so would not be a cost driver.<br /><br />And I did refer to a minimum crew to do the job - I meant the full job, not just flying up there, that might not have been clear.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[skywalker01]

Thank you for the clarification.<br /><br />So what would you propose as a solution if all three Shuttles were lost because of this before the ISS was complete?

 

[cookie_thief]

Since the <i>Endeavour</i> is already in the shop, let's go ahead and convert it and the rest of the its system to full automation. Leave the remaining shuttles as is. Then, whenever one of the manned shuttles suffers a mission stopping problem, send the unmanned <i>Endeavour</i> up in its stead. This would keep the mission relatively on track and buy time to fix the problem.

 

[mrmorris]

<font color="yellow">"I don't see however how you are going to paint on an ablator."</font><br /><br />Dow Corning 93-104 which I suggested as an ablative for the primary heat shield of G-X3 can be mixed in two different viscosities -- one which allows it to be applied directly by casting, the other allows it to be painted on.<br /><br /><i>"<b>How to apply</b><br />DOW CORNING 93104 Ablative Material can be applied directly by casting or coating or diluted for applications requiring a sprayon consistency.<br />When using a spray method, dilute the base portion to the desired consistency using heptane or naptha (see Handling Precautions) with flash points of 10°C or 16°C to obtain the best results."</i>

 

[drwayne]

"So what would you propose as a solution if all three Shuttles were lost because of this before the ISS was complete?"<br /><br />We have a problem. My proposal is in essense betting on the following three things:<br /><br />(1) You will not have damage requiring abandonment often enough to lead to that scenario<br /><br />and<br /><br />(2) The process for correctly fixing things will take enough time and dollars that the ISS will be almost a mute point.<br /><br />and<br /><br />(3) I am not betting on a solution being arrived at that is 100% effective and one that does not cause some other issue.<br /><br />Now, I use the term "bet" here deliberately to imply that I do not know all the facts, or the future. If I am proved to be incorrect in the course of time, I will of course have bet incorrectly. <br /><br />I can not state categorically whether my assumptions above are correct, I understand that they might not be.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

But is it being sprayed into a matrix, like the Apollo honeycomb, or onto a flat surface?<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[scottb50]

On an Aluminum structure the size of the under surface of Shuttle there is a lot of flexing and expansion when heated on re-entry. That was the reason the tiles were selected to begin with. <div class="Discussion_UserSignature"> </div>

 

[mrmorris]

<font color="yellow">"But is it being sprayed into a matrix, like the Apollo honeycomb..."</font><br /><br />I can't find a picture of an Apollo heat shield being manufactured. I saw one some months back of the Gemini's (can't find it either right this second). Gemini's at least, was cast, rather than sprayed. The picture I saw was of the tech pouring the ablative 'glop' into a mold that had the honeycomb reinforcement.<br /><br />In any event -- I was replying to your statement that you weren't aware of an ablative being painted on. Obviously DC 93-104 <b>can</b> be painted on. How thick a layer of the ablative that can be painted onto a given surface before requiring some form of reinforcement is another question entirely... <img src="/images/icons/smile.gif" />

 

[skywalker01]

spray-on ablators were also flown on the X-15

 

[drwayne]

"I can't find a picture of an Apollo heat shield being manufactured. I saw one some months back of the Gemini's (can't find it either right this second). Gemini's at least, was cast, rather than sprayed. The picture I saw was of the tech pouring the ablative 'glop' into a mold that had the honeycomb reinforcement. "<br /><br />I am sorry, the way I worded that was unclear. I know the Apollo material was not sprayed, it was injected into the matrix. <br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

I had forgotten the X-15 ablator, in part because I seem to recall the flight being somewhat less than successful.<br /><br />But mostly because I am just getting old...<br /><br /><img src="/images/icons/wink.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[mrmorris]

Of course the <b>root</b> issue behind your original 'paint' statement (my guess at any rate based on your reinforcement followup) is whether an ablative coating thick enough to handle the heat loads of the shuttle could be sprayed onto the shuttle underside and leading edges without the use of a reinforcing matrix.<br /><br />HeckifIknow. Not even going to begin to try to figure out the calcs required.<br /><br />Second question then would be: If it *were* possible to spray on an ablative that thick without reinforcement... what would the weight difference be over the tiles?<br /><br />HeckifIknow...<br /><br />Third question then would be: If the weight difference weren't significant... what would the manpower requirements be for removing the charred ablative after each flight and re-applying new?<br /><br />HeckifIknow...<br /><br />Fourth question then would be: If all of the above were feasible... would the failure modes of the ablative be better or worse than that of the tiles/RCC?<br /><br />HeckifIknow...<br /><br />Probably best not to switch horses in midstream... especially as there's not much distance left to ride in any event.

 

[drwayne]

You reallly have to respect someone that is willing to say<br /><br />"HeckifIknow"!<br /><br />As I recall, (and we have already demonstrated my memory is not what I remember it to be) - the issue with the X-15 flight in question vis'a'vis the ablator was related to the fact that it got charred and pitted so badly, it was hard to reprocess the surface. <br /><br />"Probably best not to switch horses in midstream... especially as there's not much distance left to ride in any event."<br /><br />I think we are in complete agreement there.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>