RTF on discovery channel

[holmec]

Its on now. <br /><br />Shuttle_guy, What is your take on the Columbia Accident Report? (that is if you see this post).<br /><br />External Tank - making sure the foam doesn't come off.<br /><br />Inflight repairs:<br /> -tiles<br /> -leading edge<br /> -scratches<br /><br /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[jurgens]

awesome!<br /><br />Thanks for telling me.

 

[holmec]

Looks like caulking techniques are very important for tile repair. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[tuckerfan]

I don't quite get that. Why not use thin sheets of heat resistant material with an adhesive back to them that the astronauts could simply peel and stick over the damaged areas. Seems to me that'd be a lot faster than trying to use a caulk gun. But I will say the engineer working on the caulk gun is a MAJOR babe!

 

[strandedonearth]

"Why not use thin sheets of heat resistant material with an adhesive back to them that the astronauts could simply peel and stick over the damaged areas"<br /><br />That would just cover over a gap full of vacuum, which would then pop when it hit the atmosphere.<br /><br />

 

[holmec]

That's right. You have to think of the environment change. Going from a vaccum to air pressure and extreme temps to more mild temps (except for reentry). Lots of things to think about. And this excersice is good for future reference on new ships and construction in space. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[CalliArcale]

I'm no materials scientist, anvel, but my first reaction to that idea is that popping the bubbles and then applying more of the material:<br /><br />a) doesn't preclude bubbles being formed in the second application (that is, you could get into an endless loop of caulk application)<br /><br />b) results in a weak layer between the first and second caulk applications<br /><br />c) depends upon being able to reasonably detect all of the bubbles<br /><br />d) depends upon being able to lance them; I don't recall them talking about this in the program, but I suspect this stuff hardens fairly quickly<br /><br />Indeed, it's better than doing nothing. But the phrase "it's better than doing nothing" isn't all that encouraging in a safety-critical application. It doesn't surprise me, though. When this all started, I figured any proposed band-aid solutions would be too immature to be reliable and we'd be left with something that is "better than nothing" but far from ideal. <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>

 

[CalliArcale]

Good question. It might be a bit of a weight issue, though. The foam is very lightweight, and reinforcing it will neccesarily make it heavier. Just deleting the white paint saved a whopping 15,000 pounds! <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>

 

[mrmorris]

<font color="yellow">"...a giant nylon stocking..."</font><br /><br />What's needed is to replace the foam with a gigantic tea cozy. At T-3 you whip the tea cozy off and launch. There's not time for condensation to acumulate and form into ice... plus you eliminate both the weight of the foam *and* the chance of falling debris. Eureka!<br /><br /><br /><img src="/images/icons/smile.gif" />

 

[SpaceKiwi]

They should talk to the F1 boys and girls about that. I'm sure they'd be happy to try and modify a few tyre warmers. <img src="/images/icons/smile.gif" /> <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>

 

[SpaceKiwi]

No, no, no, you get Grandma to crochet one for you. The tough part is choosing the wool colour. <img src="/images/icons/wink.gif" /> <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>

 

[CalliArcale]

I find that a circular-knit stockinette stitch unravels much more smoothly than crochet. I recommend knitting the ET cozy. <img src="/images/icons/tongue.gif" /><br /><br />Hmmm.....I'm kinda curious how much yarn that would take. I'm gonna do some quick estimating to satisfy myself. <img src="/images/icons/wink.gif" /> <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>

 

[CalliArcale]

Well, I found some information and came up with a SWAG that probably only vaguely approximates reality. (If you spend your lunchbreak estimating yarn needed for an ET cozy, does that mean you're a pathetic nerd, or just really weird?)<br /><br />Anyhow, I ran some numbers. Using Dale Helio yarn (I happened to have a label from it in my purse, so I could get its yardage) on size 3 US needles (that's 10 UK/Canada, or 3.25 mm if you're working in metric) and making a fairly crude assumption about how much yarn it takes to make a single stitch, it will take 1,120,272 yards of yarn. This will require 10,278 balls of Dale Heilo 100% wool yarn, which will weigh 513.9 kg. (I apologize for the mixed units, but Heilo, being a Norwegian product, is sold in metric, but the ET's sizes, being American, are quoted in imperial.)<br /><br />This actually is for a circular-knit cylinder as tall and wide as the ET, so it won't cover the aft dome and is not as efficient as it could be around the tapered top of the liquid oxygen tank. It's also an unbroken cylinder -- that is, it has no holes for SRB attach points, Orbiter attach points, or the LH2 vent umbillical.<br /><br />It's obviously not going to be as good as the foam. With this scheme, it's got the same approximate thickness and thermal protection as a Norwegian sweater. <img src="/images/icons/tongue.gif" /> Wool is a surprisingly good material for this; unlike acrylics it won't melt, and unlike cotton it has a fairly high burning temperature. (They used to make firemen's coats out of wool for this reason.) It's also a good insulator, which is of course why sheep evolved it. <img src="/images/icons/wink.gif" /><br /><br />And that's another question. How many sheep would have to be shorn to make this ET cozy? On one website, I found that the average weight of an adult wool sheep's fleece is about 2.3 kg. Assuming all of that fleece is usable wool, which it probably isn't, it would take a flock of roughly 224 sheep to provide <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>