Shuttle flights "have" been in danger for past 26 years!

Huge bomb shell out of NASA on the shuttle program on the situation with ECO sensors. With new people looking at the sensor system some more flaws have been found and these flaws may have been giving bad readings or flase readings for the past 26 year history of the program. The following are quotes from Aviation weekly which has come by some emails by the Astronaut Office on the subject.

Debate about what to do with the ECO system caused managers to totally reverse positions within 24 hr.—swinging first toward flying without relying on half of the sensors, to the current assessment that the whole ECO system must be functioning and fully redundant. Some top managers initially eyed flying with no ECO sensors operational, given that they believed new data indicate the system has always been unreliable...

“It seems to me likely that we have been flying the entire history of the shuttle program with a false sense of security and that we never had reliable protection from a [catastrophic] liquid hydrogen low-level engine cutoff,” says Wayne Hale, shuttle program manager...

The problems with Atlantis and/or its Lockheed Martin external tank (ET) are now considered so fundamental to program safety, that the difficulties have also halted any option of alternate flight operations with Endeavour or Discovery, says Hale.

The STS-122 ECO sensor problems with Atlantis will delay launch of the European Space Agency Columbus module until at least sometime in January.

“And until we come to the bottom of this mystery, we are in no better shape to launch any other orbiter,” says Hale.

Here is the link its a lengthy article.
www.aviationweek.com... (link is under Aviation Week & Space Technology)

So people can have a better understanding of the ECO and its function and location here is a image from this link which is also provided.

Twenty four propellant sensors are used in the shuttle's external tank, 12 each in the oxygen and hydrogen sections. Eight are used in each tank to measure the amount of propellant present before launch. Four in each tank, known as engine cutoff - ECO - sensors, are part of a backup system intended to make sure the ship's engines don't run too long, draining the tank dry with potentially catastrophic results, after other problems that might prevent an on-time shutdown.

NASA's original launch commit criteria required three operational ECO sensors for a countdown to proceed. But in the wake of the 1986 Challenger disaster, the LCC was amended to four-of-four because of concerns two sensors could be knocked out by a single failure in an upstream electronic black box known as a multiplexer-demultiplexer. The single-point failure was corrected during Discovery's last overhaul, but the four-of-four launch rule remains on the books.

www.spaceflightnow.com...


[edit on 22/08/06 by Canada_EH]

Wow got to say that for a space exploration thread the response here has been pretty lame. The info I guess is more of the same dangerous stuff thats been coming out of the program. Still though I know the moon hoax theory is fun but this is real world stuff on the actual program.

The more complicated the system, the greater the frequency of failure. I favor redundant simple systems.

I doubt this will put space exploration on hold for too long, it will simply increase the awareness of risk, which is as it should be. The competition for space is heating up again, and that means that the level of acceptable risk will also move upwards.

However, the next generation of shuttle designs will hopefully learn from this problem.

(And yes, there is interest, just remember that this is in the middle of a long holiday period. The wife frowns on me not coming away from the computer to greet guests when they arrive. )

Well, this is a problem...we either have 4 complex redundant systems that fail frequently or multiple simple systems that would require more study and a possible redesign. Both taking years, a ton of money and the bid going to the cheapest contractor....
Hmm...cheapest contractor.....that may be cause of these problems.
As for the next generation of spaceflight (Orion), I believe that this system (ECO) will not be used. We have officially moved backwards in time and technology as we retire the shuttle.
That is the true conspiracy/problem with NASA. There was a brilliant plan called Mars Direct which was cheap and efficient...far better than this new Apollo On Steroids called Orion. 2020 to get back to the moon...and what, 2050 for Mars...this is nuts.
This all assumes we actually got to the Moon in the late 60's, early 70's.