Shuttle repair techniques not required...

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drwayne

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Shuttle repair techniques not required for return to flight<br /><br />KENNEDY SPACE CENTER, Fla. (CBS) - NASA remains on track for launching the shuttle Discovery on the first post-Columbia mission next May or June, senior agency managers said today. While certified techniques for on-orbit repair of tile or wing leading edge damage may not be available by then, efforts to minimize foam debris impacts, coupled with a variety of other safety upgrades and the "safe haven" provided by the space station, give managers confidence the shuttle can safely return to flight sometime next spring. <br /><br />The next available launch window for mission STS-114 opens May 12 and closes June 3. Engineers at the Kennedy Space Center currently are in the process of stacking the ship's twin solid-fuel boosters and installing three hydrogen-fueled main engines. Discovery's external fuel tank, the subject of extensive insulation design changes in the wake of the 2003 Columbia disaster, is scheduled to arrive at the spaceport around Jan. 5. <br /><br />Rest of Article Here:<br />http://www.spaceflightnow.com/news/n0412/06rtfupdate/ <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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najab

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Confirming what has been said many times already - if you stop the damage from occuring in the first place, you don't need to be able to fix it.
 
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pathfinder_01

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I agree with the stop the damage idea, but it would be nice to have some ability to fix a damaged heat shield in space. Who knows a micrometeoroid impact or perhaps a faulty tile installation that wasn’t caught on the ground might doom another shuttle. It would be nice to have a plan B. <br /><br />I agree with NASA not holding off the launch but I hope they continue developing it.<br />
 
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najab

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><i>Who knows a micrometeoroid impact...</i><p>I'd be <b>way</b> more worried about the crew compartment and aft-fuselage than the TPS where MMOD is concerned. The Shuttle usually flies payload bay 'down' for precisely that reason - it can take hits on the TPS that it can't take on the more delicate upper side.<p>><i>...a faulty tile installation that wasn’t caught on the ground...</i><p>The Orbiter can loose single tiles and suffer no ill-effects. Depending on the area it can loose as many as a dozen tiles and still make an intact landing.<p>><i>It would be nice to have a plan B.</i><p>I suppose you can't argue with that, but realistically I don't see them <i>ever</i> having to use it.</p></p></p></p></p>
 
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najab

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><i>The ability to inspect and repair a vehicle would seem to be a pretty basic requirement, one that ANY traveller through distant and inhospitable lands would ask of their vehicle.</i><p>I agree. However there is a point of diminishing returns. Let's say we were planning to cross the desert in a 4x4. It would be foolish to set off without a couple of spare tires. A couple of belts and a some extra oil and coolant would be wise too. I guess we might need a fuel pump. And if we're bringing a fuel pump we might as well bring an oil pump too. I suppose the oil pan since we might hit a rock. Cylinder gaskets...never know when they might go. And if we're going to bring gaskets we might as well bring a head-end gasket. And a spare engine block. Transmission failure would be bad, so we better bring a spare one....and another 4x4 to carry it all!<p>Realistically, you check out the vehicle before you set off and carry a small amount of spare parts. And you accept that if something goes horribly wrong you will die. At least in space you won't die of starvation.</p></p>
 
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Leovinus

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<blockquote><font class="small">In reply to:</font><hr /><p><i>>It would be nice to have a plan B.</i><br /><br />I suppose you can't argue with that, but realistically I don't see them ever having to use it. <p><hr /></p></p></blockquote><br /><br />And the Titanic is unsinkable. <div class="Discussion_UserSignature"> </div>
 
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najab

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Not a fair comparison - the Shuttle is not a passenger vessel. Shuttle astronauts are paid professionals and accept the risk.<p>But, to keep with your analogy, if they hadn't made full-speed through ice-laden sea the Titanic wouldn't have sunk. It wasn't the lack of lifeboats that killed people, it was the iceberg.</p>
 
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drwayne

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Actually - taking this tangent even further - more lifeboats would not have helped - they did not get all the boats they had launched as it was.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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Leovinus

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My analogy is appropriate because it is aimed at your statement, not the type of vessel or the willingness of astronauts to take the risk. Your statement was "I don't see them ever needing to use it." It is the same mindset that made the crew of the Titanic careless, the designers of the Titanic providing inadequate lifeboats, etc. The crew knew that nothing could sink their ship and the designers didn't put enough lifeboats on because they knew they'd never be needed.<br /><br />Now NASA does not apparently agree with your assessment because they are limiting flights to ISS only in case such a repair would be required. <div class="Discussion_UserSignature"> </div>
 
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najab

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Fair enough, ignore the first part of my response - the second part is the important bit anyway.<p>Tile repair is difficult. Much better to <b>avoid</b> getting the damage in the first place than try and repair it when it happens (much better to avoid hitting icebergs than test the 'unsinkability'). NASA has done a lot to reduce the likelihood of needing tile repair. By eliminating the bipod ramp and changing the way the foam is applied they have made it highly unlikely that serious damage will occur during ascent.<p>By limiting flights to ISS only they have provided a safe-haven if damage does occur, and I assure you that given the choice they would use the safe-haven rather than attempt repair.<p>Between these two measures they have made it highly unlikely that they will ever have to do tile repair - there would have to be an event during ascent that (a) damages the TPS enough for them to be worried, but not so much that it can't be filled with a tube of caulk; (b) prevents them from reaching ISS; and (c) doesn't kill them.</p></p></p>
 
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najab

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><i>...and the designers didn't put enough lifeboats on because they knew they'd never be needed.</i><p>I read somewhere that they didn't put on more lifeboats because they spoiled the look of the ship.</p>
 
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Leovinus

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Yes. But if they felt they'd be needed, the look of the ship wouldn't have mattered. They were kept off for appearences. Post-Titanic, all the rules were changed. <div class="Discussion_UserSignature"> </div>
 
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drwayne

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"the designers of the Titanic providing inadequate lifeboats"<br /><br />Actually, the designers proposed many more lifeboats than the Titanic carried, in fact, the Titanic was equipped with special davits to allow more than one boat to be launched from a station.<br /><br />The Titanic actually exceeded board to trade requirements for the number of lifeboats. The fact of the matter is that the night the Titanic sunk was in fact not a normal night, the seas were remarkably smooth. Much of the time on the North Atlantic, lifeboats are nearly useless.<br /><br />(Sorry for the tangent, but this is an area of interest, and I couldn't help it)<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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Leovinus

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Let's start a thread over in Free Space about it. <div class="Discussion_UserSignature"> </div>
 
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drwayne

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Cool!<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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mah_fl

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So, if they do get a hole in the shuttle wing they will use the ISS as a lifeboat, untill of course all the O2 runs out. How will they all be ferried back to Earth ?
 
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Leovinus

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Easy. Breathe slow and wait for another shuttle. <div class="Discussion_UserSignature"> </div>
 
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najab

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><i>...they will use the ISS as a lifeboat, untill of course all the O2 runs out.</i><p>Oxygen won't be a problem. The Station has more than enough oxygen to support 10 people for 30 days. Don't forget they haven't really touched the supply in Quest's high-pressure tanks. Food is more likely to be a problem.</p>
 
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spayss

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The issue of external repair isn't just one of practicality and rational risk taking. It's also one of image.<br /><br /> It doesn't appear that external repair is reasonable. Therefore 'what if' there's external damage on a future Shuttle flight and it can't be repaired. A crew is killed. Yikes. Then you will see NASA paralysed with safety issues and unable to take risk not only with the Shuttle but every spacecraft it builds for the next decades. <br /><br /> So, yes, a reasonable risk should be taken if the Shuttle and NASA was the 'end game'. But it's not. Another shuttle disaster could spill over into irrational safety demands in the design of the next space mission after the Shuttle. <br /><br /> I would think that the Shuttle would by flying right now if it wasn't for the first Shuttle loss. There's accumulated paralysis (not paranoia but almost). The next generation of spacecraft will be burdened by the psychology of Shuttle failures.<br /><br /> Thinking WAY ahead. What do we want? 15 years or whenever from now the next generation of craft has a disaster (it WILL happen). Then what? It all grinds to a halt again. IF there was a third Shuttle disaster then what would be the credibility of assurance that all is ready to assume launches?<br /><br /> Yes, there's risk and yes there's an amount of ridiculous expectations. I'm just concerned that another disaster could extend the ridiculous safety expectations beyond the life of the Shuttle.
 
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chew_on_this

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The "reason" for both shuttle disasters was blind arrogance. It's pretty easy to take a chance when it's not your own life you're risking.
 
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spayss

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It's not arrogance at all. The reverse. Those involved in space exploration understand it is dangerous. The challenge is trying to make the public aware of realistic risks while at the same time not stopping all progress.<br /><br /> A more interesting question would be if, after a 2 and a half year delay in Shuttle launches, will the next flight of the Shuttle be any safer than the previous hundred plus flights? If those in charge of making the actual decision to launch were asked, in private, if the Shuttle is safer...what would they answer? Sure, they've accomplished all these 'safety requirements' but were these requirements mostly P.R. for public and congressional consumption?
 
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chew_on_this

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With challenger, the flight director knew of the risk to the the booster seals due to the extreme cold. I still remember the wry smile on his face just before the shuttle blew up. If that wasn't arrogance I give up.
 
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eldensmith

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<i>What I'd like is a little robustness in our access to leo. Multiple vehicles from multiple sources--european, american, russian, chinese, and private-sector vehicles. I'd like to see automated rendezvous and docking and universal standards so that if someone needs help, that there would always be options. During the shuttle post-mortem discussions, the thing that staggered me was the realization that--even had we spotted the damage--there was virtually nothing that could be done to save the crew. If I was running the circus, expanding my options via Deltas, Arianes, SRB-derivatives, Falcons or whatever would be on the the top of my agenda.</i><br /><br />I second this request.
 
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najab

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><i>With challenger, the flight director knew of the risk to the the booster seals due to the extreme cold.</i><p>That is a bold-faced lie. I do not appreciate your making such libelous accusations. The launch team did not know of any danger. The MCC team did not either. The launch decision was taken by MSFC managers and the content of the pre-launch telecon was not made public until after the accident.</p>
 
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chew_on_this

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So you're saying he never had any idea before that launch or previous launches that the seals could be a problem in cold weather? Baloney.
 
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