Monday, November 15, 2010

Discovery repairs continue at KSC

A total of four cracks in two metal support strips on Discovery's external tank are now confirmed, NASA says.

Over the weekend, technicians removed the cracked section from the first 21-foot strip where cracks were found. Nine-inch cracks on either side of the strip -- called a "stringer" -- formed during fueling of the shuttle Nov. 5, before a scrub for unrelated reasons.

Two similar but smaller cracks were found on the stringer immediately left of the first, likely caused when loads shifted because of the first cracks.

The cracked components are located on the tank's intertank, a ridged section between the internal liquid hydrogen and liquid oxygen reservoirs. They will be replaced with reinforced strips called "doublers."

Repairs continue at Kennedy Space Center's launch pad 39A with hopes of launching Discovery's final flight in a little over two weeks. The next launch window runs from Nov. 30 to Dec. 6.

Over the weekend, teams built a protective shelter to allow new foam to be applied to the tank within specified limits for temperature, humidity and wind.

Today, engineers plan to meet to discuss measurements related to the replacement of parts where a hydrogen gas vent line connects to the tank -- the location of a leak that caused the Nov. 5 scrub. A connecting plate and seal was installed Friday evening, and a new quick disconnect device is next.

In Discovery's cockpit, technicians plan to install a panel with 18 circuit breakers that were replaced and retested at NASA's Shuttle Logistics Depot in Cape Canaveral. An electrical glitch with a breaker associated with a main engine computer forced a launch delay early this month.

IMAGE: On Friday at launch pad 39A at Kennedy Space Center, workers prepared to install a new ground umbilical carrier plate on shuttle Discovery's external fuel tank. Credit: NASA/Troy Cryder

11 comments:

MARY said...

WHY DON'T YOU JUST RETIRE THE DAMN THING ALREADY???!!!!!!!!! PUT IT IN THE MUSEUM??????

Anonymous said...

I Think Mary has great Idea.
Sincerely,
Wang Wenbao

Anonymous said...

Retire it before it ENDS ALL FUTUREA FLIGHTS if or when it blows up. Better to be SAFE than SORRY afterwards.

Anonymous said...

Agree; Put it in a museum before something bad happens. Scrub the mission before we lose more astronauts. Saying "sorry" doesn't make thinks right for what is known beforehand.

NASA - A Lesson From The Past:

“ These KSC workers admitted they should have done more to prevent the inevitable fatal Challenger disaster .”
Careless and self-centered better describe some shuttle workers.
From NASA's news after the Challenger Disaster or NASA'S careless blunder:
“I should have done more," the engineer told me, shaking his head. "I could have done more."
That engineer and several others were not surprised when Challenger exploded 73 seconds after liftoff on Jan. 28, 1986. They worked for Morton Thiokol (now ATK Thiokol), the Utah-based NASA contractor which produced the solid rocket motors that lifted space shuttles from their launch pads. Some of those Thiokol engineers expected o-ring failures at liftoff. They knew that cold overnight temperatures forecast before launch would stiffen the rubber o-rings. They knew that stiff o-rings didn't provide a secure seal. In fact, there had been evidence of leakage, what the engineers called "blowby," on an earlier shuttle flight”

Anonymous said...

This scramble to fix on the pad is a blatant cover-up to fix a problem that is covered in foam. The only way to be sure of getting ALL the stringer cracks fixed is to strip the tank completely of foam and then inspect.

This tank was faulty from the time it left Louisianna on a barge to here. It was not constructed properly, and it could quite possibly KILL all the Astronauts shortly after liftoff.

The foam covering is hiding shoddy workmanship that was performed by labor who are no longer employed because the tanks are no longer made.

Do the right thing NASA, pull Discovery back to the VAB, DESTACK and STRIP the TANK.

Ryderhard.

Anonymous said...

There are thousands of things that can go wrong and cause a disaster for any rocket so I guess we should never launch anything or anybody into space.

Anonymous said...

To all of you calling for "retire it" or "better safe than sorry" - You are all idiots and cowards - statistics show there are 10+ deaths in this country every MINUTE due to car crashes, yet you climb into your cars every day and accept the risks...
Without the Space Program, you wouldn't have your beloved cell phones, computers, medicines, non-invasive surgeries, reliable cars - and on and on.
How about you congratulate the astronauts and engineers and technicians that risk their lives and and reputations and livelihoods to make your miserable lives a little bit better...

Anonymous said...

Please do not comment if you have no knowledge or credible sources on the subject. There's enough FUD on the internet already.

Anonymous said...

It`s amazing that all you idiots make these comments about something you have absolutely no idea about. Those that you constantly slam are people who have educated themselves in the various aspects of science and math to be where they are. They have made the space program a national treasure. Start bitching about when China or Russia take over in technology.
You should stay focused with being able to tie your own shoes!

Anonymous said...

For Pete's Sake, we, as a nation, have become so risk adverse that it's a wonder that three quarter's of the population even has the courage to get out of bed in the morning. Progress inherently demands that risks be taken. For those of you saying "scrap it", get the heck out of the way and let those interested in a better future get on with business.

Anonymous said...

The external tank is new and cracked only under the stresses of being fueled. How is the tank going to hold up to the stresses of the flight loads? Is this tank flight worthy?

I'm an aerospace engineer who used to support the launches including the Discovery. I got to say using this tank may be too risky and I wouldn't be surprised if NASA is asking this very question.