Originally posted by Rabid:
Scarry. I would not want to be on that ship. Another disaster would probably end the project.

Robert

...Ships that won't just keep NASA going, but going somewhere.

Originally posted by coyote:
Those shuttles never seemed like much more than satellite repair vans to me...

Originally posted by doug osborne:
...Interesting...you don't start building a house by putting up a ladder, you lay a foundation...

Originally posted by fantasticsound:
Oh, and in my lay-person's view, the current hope of space exploration is in the hands of Burt Ruttan and the team he's assembled to build private, affordable spacecraft that can fulfill the promise of relatively inexpensive space travel that will lead the way to making space travel commonplace.

Originally posted by Prague:
...I would say a fuel sensor to Nasa is the equivalent of a bad connector in the music biz...

Originally posted by Prague:
...Nasa is the organization that made the greatest history of the universe: The only known occurence of intelligent life going from one celestial body to another, and back. There is no other proof of this ever happening.

And they get hecklers. :rolleyes:

Originally posted by TinderArts:
I think they are finally getting this stuff right. Before the last two disaters, they'd probably have launched today with the sensor issue. There are 4 fuel sensors and it only takes 2 functioning to discover a fuel problem from what they said on NASA TV. I'm happy that they don't even want to take that risk.

Originally posted by TinderArts:
A human (or bunch of humans) made the call this time after the computer had detected the problem. This was evidenced by the live coverage on NASA's TV coverage with live control room feeds.

Originally posted by fantasticsound:
Regarding hecklers; If this was aimed at my buddy, Techristian, then so be it. Te, you deserve it for your hyper-cynical thread name.

Absolutely not, Prague! The reason they stopped the launch is because this sensor is absolutely critical to their survival on the mission. Fuel is in short supply and must be carefully rationed for whatever they must do, that they can return from space. The issues are far different than if the sensor in your car fails.

The fuel sensors in question are in the external tank. Their purpose is to shut down the shuttle main engine if the fuel runs out, so that the engine remains controllable. This is only applicable to the ascent phase of the mission, not the return phase. In reality, the event they are there to detect will never happen as fuel sufficiency is calculated quite conservatively. However, if the sensors were to falsely report no fuel during the ascent, that would not be good.

According to the news reports I've seen this problem arose months ago in testing and the engineers could not determine the cause. Frankly, that scares the cr*p out of me. That they couldn't determine the problem or wholly replace the system with a fully tested and operable sensor is, IMO, unacceptable.

The sensors themselves are in the external tank, near the bottom. Swapping out external tanks (from the backup mission) would swap the sensors. However, the technicians weren't able to determine if the sensors are at fault, as opposed to cabling or computer problems, because at some point in the troubleshooting process it all started working correctly again and couldn't be made to malfunction.

You do remember that members of NASA were responsible for allowing the inclusion of the faulty rocket booster valve that destroyed Challenger and killed the astronauts aboard, right?

The Challenger accident was caused by a faulty o-ring in one of the solid rocket boosters. Or, more accurately, by the decision to launch in cold temperature conditions that were specifically warned against by the SRB manufacturer, Morton-Thiokol. Rubber seals don't work too well when they're frozen.