NASA may bend rules to continue the launch.

apnews.myway.com...

CAPE CANAVERAL, Fla. (AP) - With the countdown entering its final hours and a fuel gauge problem still unexplained, NASA said it is prepared to bend its long-standing safety rules to launch the shuttle Tuesday on the first flight since Columbia's doomed mission 2 1/2 years ago.

Discovery and a crew of seven were set to blast off for the international space station at 10:39 a.m., after a two-week delay caused by a malfunctioning hydrogen fuel gauge in the spaceship's giant external tank.

Nature, rather than the fuel gauge, could ultimately decide whether Discovery takes off. Forecasters put the odds of good launch weather at 60 percent, with rain and storm clouds both posing threats.

NASA had the paperwork ready to go in case the equipment trouble reappeared and the space agency's managers decided to press ahead with the launch with just three of the four fuel gauges working. That would mean deviating from a rule instituted after the 1986 Challenger explosion.

should they continue the launch even though they cant actually find out wat the problem is? its pretty risky to brush even a minor problem even if its false alarm to the sensors.

From what I understand, it's not really bending rules. NASA requirements are to have two working backups for every piece of equipment, so with 4 redundant sensors, if one is malfunctioning, it still meets specs.

My understanding is that since there are SO many things that could possibly go wrong with the overall system, that the "rules" are more like relative priorities.

There is a ranking of priority items and severity if failure occurs. What's interesting is if you study all of the launches (in the writeup from the Columbia accident) which I had to do for an engineering dynamics course, you will notice that almost all of the launches had frozen insulation ripping off the big booster tank. But it was considered a low priority item.

Likely having less than 4 sensors is a relatively high priority item after the Challenger situation, but, it was not the fault of the sensor, it was the fault of the seaming design and the rubber O-rings, and the cold launch temperature that was the root cause of the Challenger accident.

The reason we have redundant sensors is so that if one or two fail we have backups. So the question obviously is is it worth scrapping a whole launch for a redundancy? If you consider that the fuel system has a very good success record in warm temperatures, this is likely not a significant issue. It's interesting to note that both of the failures occured within a week of each other in late January (with subzero temperatures overnight).

Ed

I think the problem here is more a lack of understanding why the sensor is failing rather than its actual failure. As I said with four sensors, the failure of one isn't much of a problem in and of itself, but the fear is it could be symptom of a larger problem.

Hasn't NASA been bending or ignoring rules to launch for years?

The next thread about this shuttle will be about it's crash.

[edit on 7/25/05 by flipjargendy]

[edit on 7/25/05 by flipjargendy]

I just cant understand why the people that built it, cannot figure out why it doesnt work right.


Doesnt that seem...... sad?

Here is an intersting editorial that is relavent to this.

But no amount of engineering caution can make space flight perfectly safe. The speeds and heating rates are extreme, and the technology is unavoidably pushed close to its limits. Every human flight carries a potentially deadly risk. Thus, every human space flight must pursue mission objectives worth dying for.[...]
The shuttle and space station will be footnotes at best or, at worst, cited as examples of technological myopia.

How can we evolve our human flight program once again into a historic endeavor? The answer seems clear: We need to start exploring again. The obvious destination this time is Mars, a potential human habitat of unrealized possibilities in the best case (or at least a refuge for human survival in the worst). No other place outside Earth in this solar system offers such interesting possibilities.

The human exploration of Mars may well have to be extended beyond this century to be feasible. It is logically an international project, building upon the collaborations developed around the space station. And it encompasses a human destination that many would accept as worth dying for, just as were great geographic explorations in the past.

Intersting way to look at it. But then again an orbital space station would probably be necessary for any expeditions and colonization of mars. If the shuttle and ISS are footnotes, then they might be footnotes that Space Exploration Historians of the future will pay special attention to.

Originally posted by Dulcimer
I just cant understand why the people that built it, cannot figure out why it doesnt work right.

Doesnt that seem...... sad?

What, it suprises you that a machine built from over 375,000 parts, from over 400 different companies that were each the lowest bidder on the parts they designed/built, might have a few issues?

I'm getting a bit bored with the Shuttle now...We need the next generation of Spacecraft.
It should have been replaced years ago.
We should be walking around Mars now at least!
Ever since Apollo, everything (manned)has gone far too slowly.
We seem to have lost the momentum(and the funding)...It's all very sad.

Latest updates:

1118 GMT (7:18 a.m. EDT)

As shuttle commander, Collins is the first astronaut to board the shuttle. She is taking her forward-left seat on the flight deck.

Collins has flown in space on three earlier missions, becoming the first woman shuttle pilot and commander. Read her biography here.

1112 GMT (7:12 a.m. EDT)

Commander Eileen Collins has made her way across the catwalk-like Orbiter Access Arm to the White Room positioned against the side of Discovery. The closeout crew is helping her don other survival gear.

1111 GMT (7:11 a.m. EDT)

The Discovery astronauts have reached the 195-foot level of the tower.

www.spaceflightnow.com...
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Everything seems to be going smoothly


I agree that the shuttle is too old, and should be replaced. If only they hadn't 'liberated' Iraq, they could have spend much more on research into the shuttle's replacement...

you gotta hate a government that's more than willing to spend hundreds of billions on fighting wars but drags its feet when putting up the currency for a shuttle replacement. With the funding NASA could come up with something incredible no doubt.