STS-114 Mission Update Thread (Part 5)

[mrmorris]

<font color="yellow">"Assuming you *could* completely shutdown ..."</font><br /><br />Once you've assumed the impossible, everything else, no matter how impractical, must be... um... pointless?<br /><br />Who cares if it requires the impossible? The orbiters aren't made to stay in orbit for extended periods of time. Start with this assumption rather than inventing ones that cater to what you <b>wish</b> were the case.

 

[emerrill]

"Once you've assumed the impossible, everything else, no matter how impractical, must be... um... pointless?<br /><br />Who cares if it requires the impossible? The orbiters aren't made to stay in orbit for extended periods of time. Start with this assumption rather than inventing ones that cater to what you wish were the case. "<br /><br />What the hell? No where did I say that I 'wish' this was the case. I know how things work, and that the shuttle is not designed for long duration stays.<br /><br />It is a simple theoretical question. Not ever thoretical. What is the rate that the cyro's are simply lost at?<br /><br />Its a simple question, there is no reason to start attacking for no apparent reason.<br /><br />-eric <div class="Discussion_UserSignature"> </div>

 

[mrmorris]

<font color="yellow">"It is a simple theoretical question. Not ever thoretical. What is the rate that the cyro's are simply lost at?"</font><br /><br />Here's a simple theoretical question. If humans could fly -- at what rate would they burn calories?<br /><br />Simple, theoretical, probably reasonably easy to calculate (given sufficient data about the human in question, air density, and the muscle fiber involved) and <b>completely</b> pointless. Therefore, why would anyone have done the calculations, or have them close at hand, or care? The cryo question has the exact same problem... which is almost certainly why SG responded as he did... although he did leave off the 'Who cares?' portion of his answer. <img src="/images/icons/smile.gif" />

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>The vehicle can not survice with no power. It could not be powered back up. <p><hr /></p></p></blockquote><br /><br />If I'm not mistaken, this is because it needs power to run its heaters, and without the heaters, it will be fatally damaged, correct? That is totally apart from the problem of servicing the fuel cells so they can provide it with power again for a hypothetical descent.<br /><br />Thermoregulation is a problem that most laypeople forget about, and understandably so; it's not a very big deal here on Earth. In space it's a huge problem, which absolutely every spacecraft has to deal with. I remember towards the end of Mir's lifetime when its batteries started to go funky it would have problems keeping a constant temperature; the flight controllers resorted to putting it into a slow roll so that solar heating would be more even. (Sort of a rotisserie concept.) <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[emerrill]

"Simple, theoretical, probably reasonably easy to calculate (given sufficient data about the human in question, air density, and the muscle fiber involved) and completely pointless. Therefore, why would anyone have done the calculations, or have them close at hand, or care? The cryo question has the exact same problem... which is almost certainly why SG responded as he did... although he did leave off the 'Who cares?' portion of his answer. "<br /><br />Actually to the contrary, I bet the number is well known somewhere. Its an important number. If you know you are using x amount per time unit, you also have to know how much loss you have per time unit, or you wouldn't know how much time you have left. Now cryo's boil off at a *relatively* high rate (relative to other fuels), but I dont know how that rate compares to the normal use rate, maybe it's a low amount <1%. <br />But I would pretty much guarantee that this number is known. You have to know that once you fill the tanks, you are going to lose some amount per time unit, even if your fuel-cells are not running.<br /><br />Im not asking for any particular reason. It has nothing to do with being able to save a stranded shuttle or anything, its just a piece of information. I think you confuse 'wishing things' and just curiosity.<br /><br />-eric <div class="Discussion_UserSignature"> </div>

 

[emerrill]

"Thermoregulation is a problem that most laypeople forget about, and understandably so; it's not a very big deal here on Earth. In space it's a huge problem, which absolutely every spacecraft has to deal with. I remember towards the end of Mir's lifetime when its batteries started to go funky it would have problems keeping a constant temperature; the flight controllers resorted to putting it into a slow roll so that solar heating would be more even. (Sort of a rotisserie concept.)"<br /><br />Yeah, thermo is a huge problem. On our satellite we have micro thrusters that output alot of heat. We ending up being able to just use some emissive paint, and a barbecue roll.<br /><br />-eric <div class="Discussion_UserSignature"> </div>

 

[shuttle_rtf]

>RTF said there is a short window in Dec. I was not aware of thaat. It is a mote point, I am afraid, because of the ET problems. The ET fix will not be ready to allow a launch in 2005. That is only my opinion. <<br /><br />I agree and yes, a moot point for sure.<br /><br />I was taking that information from a post MMT press conference in which Wayne Hale was answering a question on the next launch possibility...and he listed off the next four windows.<br /><br />Info just in from MAF claims that the PAL Ramp question (remove, modify etc.) is due to be answered 'imminently. I'll see if I can ask around - and I'm sure we'd all appreciate if you hear anything, SG.

 

[radarredux]

> <i><font color="yellow">The ET fix will not be ready to allow a launch in 2005.</font>/i><br /><br />I am sure this was covered earlier, but...<br /><br />Has there been any studies on how the tanking tests affect the integrity of the foam?</i>

 

[phaze]

For your viewing pleasure:<br /><br />"Hi Mom!"<br /><br />From Wednesday morning's EVA. Pictured is Soichi Noguchi, the photographer is Steve Robinson.

 

[steve_the_deev]

Hey SG, I just talked to the MPS people ans they told me there was no clear answer to the ECO failure and now it works. Go figure.<br />I felt all along it was a grounding issue of which they did find and fix items in that arena. Have you heard of a final reason of why ECO sensor had a problem the firsty go thru? Also on the PAL ramp I'd hat to see a complete redesign. My thought was so simple I had a few Engineering folk give me the double take. But remember we flew the first two or three Shuttles with that white paint. I am quite sure they could cout the PAL with what we now have in the Polymer world of High / Low Temp coatings that would adhere to the foam with very high strength thus preventing either the PAL foam or the coating itself to come lose. Very simple fix. At firstI was thinking why not paint the complete ET like the good ole days but that's a weight issue and larhe swaths of paint may come off during ascent.<br /><br />

 

[halman]

1207, et al,<br /><br />What really needs to be discussed, I believe, is sacrificing payload capacity for safety. Foam is by its very nature a fragile material, considering that it consists largely of air. To create a foam that will withstand supersonic flight is an extraordinary feat, especially when considering that the foam is anchored to a metal which is cooled to around -270 degrees C. Although an earlier formulation of the foam was not as susceptable to shedding, (as I recall,) it was deemed unsuitable for use. Now we are facing another delay in flying because this fragile material is not remaining intact during the stresses of launch.<br /><br />The only certain way to eliminate this problem is to add an additional anchoring system to the foam installation, something which will hold the foam in place even if a section of it is not adhering to the tank. To do so will require mass, in the form of some type of filaments, possibly in the shape of a net. This mass will subtract from the mass that the orbiter can carry to orbit. The penalty may be so severe that the modules the shuttle is supposed to deliver to the space station will excede tha capabilty of the shuttle.<br /><br />Considering that a Shuttle Derived Heavy Lift Launch Vehicle is the most likely launch vehicle to succede the shuttle, why not put off the completion of the International Space Station until such time as the SDHLLV is on line, and use the shuttle to collect the modules in orbit and haul them to the station? We would not be sacrifing the space station for the shuttle, and we could avoid sacrificing astronauts for payload capacity. <br /><br />Modifying the External Tank in such a way that loose foam cannot be shed would not take long if mass were not a concern. Accelerating the development of the SDHLLV to be used in tandem with the shuttle could be financed in part with savings from reduced shuttle flights. This would move all of our efforts in space forward, without sacrificing safety <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[shuttle_rtf]

>MSFC folks do not talk to KSC folks very much......<<br /><br />They love you guys too <img src="/images/icons/wink.gif" />

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>Not to insult anybody, hHowever I try not to deal with thermo guys; they tend to be a bit...strange. I am sure they think engineers are strange as well. <br /><p><hr /></p></p></blockquote><br /><br />LMAO !!! <div class="Discussion_UserSignature"> </div>

 

[shuttle_rtf]

I've got images of their mums still wrapping them up in vests and heavy coats with mittens, and sun screen factor 500 when out in the sun <img src="/images/icons/wink.gif" />

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>Considering that a Shuttle Derived Heavy Lift Launch Vehicle is the most likely launch vehicle to succede the shuttle, why not put off the completion of the International Space Station until such time as the SDHLLV is on line, and use the shuttle to collect the modules in orbit and haul them to the station? We would not be sacrifing the space station for the shuttle, and we could avoid sacrificing astronauts for payload capacity. <p><hr /></p></p></blockquote><br /><br />Good idea. Also will insure the SDHLV move forward in a fast pace. But unless I read it incorrectly, it will be a while before the SD Heavy in-line configuration will come on line.<br /><br />Realistically there's no foam that will not shed. Modifying this on the ET is no small task without completely redesign the ET. Look at the "newer technology" EELV foams, particularly the Delta IV, they still break and shed.<br /> <div class="Discussion_UserSignature"> </div>

 

[lunatio_gordin]

whoa. that was a weird double post. never seen that happen before...

 

[lunatio_gordin]

oops. i didn't realize there was that many more pages XD

 

[bushuser]

All the important information about the Discovery TPS has come from on orbit inspection. The elaborate and restrictive precautions made to photograph launch were a good engineering study, and should be repeated once after the ramp modification. However, other than some really entertaining pictures, launch photography didn't add much to safety evaluation. They should soon deemphasize daytime launch, in favor of thorough laser/photo inspection prior to reentry.<br /><br />I suppose there is little need for inspection if the future brings us an in-line launch configuration. No more "stuff falling on people"

 

[drwayne]

So I take it you would not put much value in the boost phase data as an indication of areas that should get the thrice over?<br /><br />Wayne<br /><br /> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[bushuser]

It was useful this time, and should be used again to evaluate any changes they make in the ET for the next flight. I don't think it should be a priority for every launch. Careful inspection before reentry is going to be a priority from here on out to shuttle retirement.

 

[dougbaker]

I am amazed at NASA.<br />I am reminded of an old saying about cost, delivery time, and quality. You can never have it fast, cheap and good. You can’t have all three, and if you try to optimize for one, the other two may go to an extreme. So you can have it quick, but it may be low quality and be expensive. If you want high quality (safety, low risk), it most likely will be slow and expensive. I have feared that NASA has put just a great importance on low risk and safety, that will take a very long time to get anywhere with space exploration or the cost will be so high, not even the US Federal government can pay for it. I don’t want to see any one get killed or injured, but if this approach was used for other high risk but high reward area, we would still be flying planes with propellers and driving vehicles pulled by horses. So fixing a problem could take a long time, and then.. a surprise. NASA is actually going to allow an extra task on the EVA with a tool that was not designed and tested for years before being used. They are going to use a modified saw and grey tape solution to “fix” the shuttle while in orbit. Wow. Perhaps there is hope or else NASA is really a two headed monster.<br /><br />And to be very clear, I am commenting on the organization not individuals that are often constrained by the management and history of the organization.<br />

 

[halman]

propforce,<br /><br />Without redesigning the External Tank, there are ways to keep foam from shedding. But they all add mass to the tank, such as a Kevlar jacket for the ET, or a a net immersed in the foam. But such solutions allow flying without the risk of foam strikes, which is what is badly needed right now. The shuttle is still a very valuable tool, for many things. Grounding the fleet while searching for a perfect solution is not desirable, I believe. Accepting lost payload capacity in return for resuming flying in the near future is. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[shuttle_rtf]

EVA 3 starts in 90 minutes. Everyone excited or nervous?<br /><br />I'm both.<br /><br />I'm expecting another superb triumph for the STS program today...and once again it's going to come down to a skilled astronaut and a hacksaw (if required).<br /><br />TOTALLY different senario, but this reminds me of the filter they built on Apollo 13..out of sticky tape and spare material. I know this has nothing to do with an emergancy like Apollo 13, but still, it's a load of brains and the simply things that make it here.<br /><br />Reminds me also of a quote from that terrible - yet visually fun - film Armageddon: "Just digging a hole.......in frigging outer space" <img src="/images/icons/smile.gif" />

 

[bobw]

I hope to see the station arm change base points. I don't think I have ever seen that before. I don't know if there are any cameras to view it and I doubt they will have one of the astronauts keep his helmet camera on it the whole time. <div class="Discussion_UserSignature"> </div>

 

[SpaceKiwi]

<blockquote><font class="small">In reply to:</font><hr /><p>I'm expecting another superb triumph for the STS program today...and once again it's going to come down to a skilled astronaut and a hacksaw (if required).<p><hr /></p></p></blockquote><br /><br />My money is on a simple pull out of the spacers. I'm most nervous that the side walls of the adjacent tiles may be damaged in the process, but that is probably somewhat based in fear than fact.<br /><br />I'm overall really pleased with how the inspection process has worked out, most importantly with the gathering of data on ascent. I agree with SG (always the safest bet!) that night launches should be possible once they have verified the ascent data collection process is accurate.<br /><br />Despite the fact that various 'sensationalist' news organisations have been trying to beat up a story with debris hit's all week, I think it's 'great' to see problems and be able to verify them accurately now. I liken this whole TPS/ET situation to those old maps you see from the days of sailing ships, with the serpents drawn in on the edges to denote areas that hadn't been explored at that time. The media have tried to create some TPS serpents, but I think this process is going to be an overall triumph for NASA and Shuttle.<br /><br />Which brings me to my final observation. It is somewhat disappointing that it looks like the Shuttle fleet will be stood down until the foam shedding situation is addressed. Whatever that means, as foam shedding will remain a risk no matter what they do. Rather like a jet sucking a bird or birds or volcanic debris through the intakes. <br /><br />The point is you can't cover for every eventuality and the law of diminishing returns suggests that we are probably at that point now in my view. The fact is the PAL debris didn't hit the Orbiter and, if it had, NASA now has the capability to detect it. For 20 something remaining flights, I'm not convinced another ET redesign is entirely necessary. Yes the PAL fo <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>