NASA news conference~~~ Live Thread

MSNBC | 1-05-03 | Dog

[XBob]

173 - "I've been saying since Monday on this forum that it's not foam. "

see 178

the tank insulation is a totally different animal than the tile insulation, and much more coheresive.

though, the more info I get, the more I think it is possibly ice saturated tank foam.

[XBob]

It would be much better to have several CRV's launched into various orbits ahead of time,

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good idea, see 179

[XBob]

If the ice weighted 1 lb and was going 300mph, it would have 6K ft-lbs of energy. the heavier the patch, the less the relative speed of the impact - remember that the debris was going the same speed as the orbiter when it broke loose. A light fluffy object would decelerate rapidly from the air-resistance, but a heavier object, such as ice, would both maintain its forward momentum, and be more prone to flutter outward. If uncoated ice, a flat piece of ice would likely begin coming apart just from the stresses when it turned perpendicular to the air-stream. 273 posted on 02/06/2003 11:22 AM PST by lepton

[XBob]

If the ice weighted 1 lb and was going 300mph, it would have 6K ft-lbs of energy. the heavier the patch, the less the relative speed of the impact - remember that the debris was going the same speed as the orbiter when it broke loose. A light fluffy object would decelerate rapidly from the air-resistance, but a heavier object, such as ice, would both maintain its forward momentum, and be more prone to flutter outward. If uncoated ice, a flat piece of ice would likely begin coming apart just from the stresses when it turned perpendicular to the air-stream. 273 posted on 02/06/2003 11:22 AM PST by lepton

[XBob]

If the ice weighted 1 lb and was going 300mph, it would have 6K ft-lbs of energy. the heavier the patch, the less the relative speed of the impact - remember that the debris was going the same speed as the orbiter when it broke loose. A light fluffy object would decelerate rapidly from the air-resistance, but a heavier object, such as ice, would both maintain its forward momentum, and be more prone to flutter outward. If uncoated ice, a flat piece of ice would likely begin coming apart just from the stresses when it turned perpendicular to the air-stream. 273 posted on 02/06/2003 11:22 AM PST by lepton

[freepersup]

The foam would hit with more speed, but wouldn't the ice have more force ? I am thinking of a pine cone striking a 3/4" sheet of plywood at 500 mph, versus a 1" steel ballbearing striking a 3/4" sheet of plywood at 300 mph. I know this isn't comparing apples to apples.

How porous is the foam insulation ? I ask, because you commented on possible ice laden insulation. The added weight of moisture/ice in the foam, could be a contributing factor in the separation of the foam from the main tank.

[snopercod]

Speaking of good ideas, why not have a video camera on the ET looking back at the shuttle tiles? I know they installed one in the ET Aerospike area once for that purpose. It would be even easier to put one in the Intertank area.

The problem might be getting the video to the ground, especially after ET Sep.

It could be done on the boosters, too.

[Rockitz]

Some colleagues here are wondering if it's a piece of foam with ice attached. That may explain the rigidity of the piece and yet the higher combined density relative to just a piece of foam. Any votes for ice-foam combo out there?

[XBob]

186 - "How porous is the foam insulation ? I ask, because you commented on possible ice laden insulation. The added weight of moisture/ice in the foam, could be a contributing factor in the separation of the foam from the main tank."

I don't know, however, I think it is a type of closed cell polyurethane, so it should not be very porus. However, I think the tank had been sitting around for nearly 5 years since manufacture, so the Florida humidity could have gotten to it.

Sonar5, do you know how old that tank is?

[XBob]

Speaking of good ideas, why not have a video camera on the ET looking back at the shuttle tiles?

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This sounds pretty do-able to me. and there should be no great problem for telemetry/monitoring.

[XBob]

ice-foam combo ?

I vote - consider it as a possibility.

However, spectroscopic analysis should be able to determine composition.

[Bryan24]

Begging your pardon, but I do have a good idea of the time it takes to prep a shuttle and payload. We decided to launch shuttles with NO backup plan. Shoot, we planned on flying thee things dozens of times. Yet we can't have 2 ready to go at the same time?

NASA built a craft that an errant duck would render mortally wounded. The craft has 34 bajillion different parts. Yet, once you ight the SRBs, for all practical purposes their fate was sealed.

BTW, the CRC (crew rescue capsule) would be an unfueled module. What is it's purpose?

A crew of seven launches and serious mishap occurs during orbit. Teh shuttle sustains serious damage that requires 3-4 astronauts to go rescue them. You can't bring 11 back in the shuttle cabin.

[freepersup]

Lay person here- casting a vote for ice laden foam insulation as prime culprit.

[freepersup]

Thanks for the perspective and detailed explanations. I had a bit of an epiphany because of it. I was really missing the boat with regards to the difficulties and complexities involved in the pursuit of a spacecraft by another spacecraft attempting orbital syhchronization. My head hurts- just from thinking about it.

If fuel is a problem (volume and weight) why doesn't NASA pursue the idea of powering a shuttle rescue vehicle with a nuclear propulsion system ? Is that feasible ?

As snopercod suggested, one or more rescue vehicles could be prepositioned in orbit, loitering, and the shuttle could then be launched into an orbit containing a rescue vehicle.

[Frank_Discussion]

Yeah, the whole "changing-orbit-angle" thing is a problem with the way we do things. Chemical Rockets are stone-age stuff, but it's what is used by all the space agencies. It's the only thing that will lift the loads to orbit. But when you've used it up, there's not much you can do to manuever on-orbit.

You are right, a true nuclear rocket could provide quick assistance, but the greenies would have a stroke. There IS a new program coming up that uses nuclear power to run electric engines, Project Prometheus. It was to have been a big announcement in the NASA budget briefing on Monday. Current events eclipsed that announcement.

[Mamzelle]

Just started to read...was there any comment on military photography of the Columbia while in orbit?

[freepersup]

Check out this thread- It's just what the good doctor ordered.

http://www.freerepublic.com/focus/news/838015/posts?page=1

[freepersup]

Here it is again, hot linked...
http://www.freerepublic.com/focus/news/838015/posts?page=1

[freepersup]

I haven't read completely through this thread, but the topic is military photos of Columbia's left wing and appears to provide a better lead in story (more facts in the body of the article).
http://www.freerepublic.com/focus/news/837858/posts