STS-121 Update Thread: Part Two

bobw · May 31, 2006

Yes, I hope everything goes smoothly. T - 1 month and counting. <div class="Discussion_UserSignature"> </div>

edkyle98 · May 31, 2006

I'm not sure about the ET sensors, but you need a micro-ohmeter to measure really small resistances. Such meters use four test probes rather than just two, allowing the lead and contact resistance to be automatically cancelled out. I've used such instruments to make repeatable resistance measurements down into the sub-milliohm ranges. These meters can also often measure through higher resistance ranges than a standard multi-meter (giga-ohms or more rather than just mega-ohms). - Ed Kyle

josh_simonson · May 31, 2006

I used one of those in an internship to characterize connector resistance degradation when the duts were exposed to humidity and corrosion chambers. It wasn't that hard, but the kiethley ohmeter was probably expensive.

bobw · May 31, 2006

Thanks for the info. about the meter. I googled eco ohm, etc. and found a link to an article about the sensors with a picture of someone from USA using a very nice looking instrument. I'll have to look up how one of those meters work but I don't think there is much of a chance of the boss signing off on one for me. I work in an industrial place and we just don't seem to have that kind of problem. Anyway, if I had one I would probably have to spend the rest of my life tightening ground wires LOL. http://spaceflightnow.com/shuttle/sts114/050720newdate/ "He said the grounding problem was extremely subtle, adding "we are talking in fractions of a milli-ohm (of resistance). "That doesn't seem like very much," he said. "But it matters from the point of view of the box. If the box has these different channels of electronics running through it and it's got power and grounding for each of those separately and if they start to get off a little differently from each other, that's when the circuits can get tripped up. So a very small amount of resistance can cause those grounds to flip up and down and that can happen when you get a large electrical transient" in another system." I think everything went OK for the launch after they fixed the ground but the article said they changed the cables, too, so that might have been it. <div class="Discussion_UserSignature"> </div>

jschaef5 · Jun 1, 2006

I'm not sure if i've ever seen a picture of the ET from the shuttle right after seperation. Is this part of one of the new camera's they put on or has it always been there or just since columbia? <div class="Discussion_UserSignature"> </div>

SpaceKiwi · Jun 1, 2006

Not only still photography either. There was some quite dramatic video footage taken on STS-114 of the ET beginning its decent towards atmospheric destruction. As I recall a big chunk of foam drifted through shot also. <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

baktothemoon · Jun 1, 2006

How many days until rollout to the pad?

bpcooper · Jun 2, 2006

It's been on the pad since May 19. <div class="Discussion_UserSignature"> -Ben </div>

baktothemoon · Jun 3, 2006

?????!!!!!! Oh well, I guess that's what happens when you step away from the computer for a few weeks. Dang, why doesn't the news ever cover that? Shows how much they care.

bushuser · Jun 6, 2006

How big a job is it to swap the electronics box?

earth_bound_misfit · Jun 6, 2006

"the SRB IEA problem was isolated and it can be repaired at the launch pad." I wasn't ever aware there was a problem. What is the IEA anyway? I've been quite surprised how quiet this thread has been, with only a month (hopefully) till launch, I would have thought everyone was getting excited, and posting questions etc. <div class="Discussion_UserSignature"> ----------------------------------------------------------------- Wanna see this site looking like the old SDC uplink?Go here to see how: SDC Eye saver </div>

SpaceKiwi · Jun 7, 2006

<blockquote>In reply to:<hr />I would have thought everyone was getting excited, and posting questions etc.<hr /></blockquote> I'm definitely ready to fire up, e_b_m, it's been too long since RTF1 for my liking. They've got several hours of pre-flight briefings happening on Friday our time, so I'm sure there will be plenty of questions to come out of that. <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

earth_bound_misfit · Jun 7, 2006

"The IEA is a Integrated Electronics Assembly. There are 2 of them. They have most ofl the avionics required by the SRB." Thanks SG. So I guess that's the part that flicks the Bic that ignites the wick <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> ----------------------------------------------------------------- Wanna see this site looking like the old SDC uplink?Go here to see how: SDC Eye saver </div>

earth_bound_misfit · Jun 8, 2006

Awesome News! <div class="Discussion_UserSignature"> ----------------------------------------------------------------- Wanna see this site looking like the old SDC uplink?Go here to see how: SDC Eye saver </div>

SpaceKiwi · Jun 8, 2006

I've videoed the preflight briefings for review as they occured overnight my time, though I caught the last half of the EVA briefing and the '121 crew briefing. I found Lindsey's comment's on max Q to be particularly interesting. Basically he has said that, due to the lesser weight Discovery is hauling to orbit this mission, they have some room to play with the flight profile on ascent. If I have it correctly, they will be throttling down the SSME's earlier as they approach max Q and not throttling back up to full 104% immediately following it? The reasoning being that such a thrust profile will exert less forces on the ET while travelling through the lower, denser part of the atmosphere. I think Lindsey said about a 7% 'improvement' in the forces being exerted on the ET. I guess the ascent profiles change from mission to mission, though I cannot recall such a 'major' (I use that word advisedly) change so early into flight? While I imagine this is a safety driven change to ascent primarily, I wonder how this will impact getting 'good' data on the ET mods? Surely they will not have this luxury of going a little slower in the early part of ascent on every mission due to weight considerations. As a test flight, I would have thought it would be better to run the more common flight profile with the correct forces being exerted on the ET? <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

scottb50 · Jun 9, 2006

Makes sense to me. <div class="Discussion_UserSignature"> </div>

montmein69 · Jun 13, 2006

HAs the ET 118 for Atlantis been shipped to KSC ? Can any delay in the preparation of STS 300 (on demand rescue mission) have an impact on the 1st of july launch of STS 121 ? <div class="Discussion_UserSignature"> </div>

SpaceKiwi · Jun 14, 2006

What is the significance of the various wing designs and colours of the US Astronaut name patches? Is this by Astronaut Class or seniority or what? <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

norm103 · Jun 14, 2006

i belive some of the various designs are cus of the diffent in the usn and usaf.

SpaceKiwi · Jun 14, 2006

<blockquote>In reply to:<hr />Are the names color coded to reflect "flown/ not yet", Shuttle_guy?<hr /></blockquote> I thought of that potential distinction also, but it is definitely not the case on the basis of the '121 crew. Lindsey and Kelly have both flown, yet one patch is gold and the other silver. I tried to match the colours up against several factors, including time in the Corp, military vs civilian, pilots vs non-pilots, flight deck crew vs mission specialists. Nothing seems to fit for the insignia and colours displayed on the '121 coveralls. SG will crack the code for us, but no doubt he's tied up with the TCDT at the moment. <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

SpaceKiwi · Jun 14, 2006

<img src="/images/icons/laugh.gif" /> That's where the hi-res version of the photo at nasa.gov came in. Unless they've been pulling some serious wool over my eyes the last six months I've been following their training, I think I've got their number in the prank-pulling dept. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

SpaceKiwi · Jun 17, 2006

The launch date of Discovery made this morning's radio news over here. A couple of soundbytes from Bill Gerstenmaier on the rationale for the decision as well. I surely can't wait for this, I certainly hope they can get away on the 1st. That would be about a 7am Sunday launch from my perspective, couldn't really get any better. <div class="Discussion_UserSignature"> Who is this superhero? Henry, the mild-mannered janitor ... could be!-------------------------------------------------------------------------------------------Bring Back The Black! </div>

askold · Jun 18, 2006

No-go from 2 senior managers, but the mission's going to fly. Good idea or not? CYA or a real concern? "Two senior NASA managers – chief engineer Chris Scolese and Bryan O’Conner, the associate administrator of Safety and Mission Assurance – did have concerns over the potential risk of foam debris posed by a number of insulated ice frost ramps along Discovery’s external tank, NASA officials said. “From their particular discipline, they felt they wanted their statement to be No-Go,” William Gerstenmaier, NASA’s associate administrator for space operations said."

gawin · Jun 18, 2006

An echo from the past…… Morton Thiokol engineer said don’t fly, bosses said fly… end result…. Difference this time engineers are making it known to public so that if something does happen they have CYA. Sad thing is they are between a rock and a hard place. They want to see it fixed and fixed rite. there is no time nor budget to get it fixed. So they are relying computer models and no real world testing and hoping for the best. So they say don’t fly but we don’t feel it is a total show stopper.

earth_bound_misfit · Jun 18, 2006

Well, with the on orbit craft scaning, there should less chance of loss of life. Eh? Bloody foam, it's a right royal pain in the "you know where". <div class="Discussion_UserSignature"> ----------------------------------------------------------------- Wanna see this site looking like the old SDC uplink?Go here to see how: SDC Eye saver </div>

STS-121 Update Thread: Part Two

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