NASA dig deeper on ice issues

by Chris Bergin

Wednesday’s fuelling test was carried out in real time on the launch pad to check for any flaws. The Debris Verification Board were evaluating concerns of foam impacts from the main fuel tank, while engineers have been checking the effect of ice upon the External Tank (ET-120).

Both tanks have been modified since the Columbia (STS-107) disaster in 2003 – when the Shuttle tore apart on re-entry into the Earth’s atmosphere – because of a piece of insulation foam that had broken off the main fuel tank. This subsequently breached the left wing’s leading edge on assent and caused the Orbiter to break up.

Ice formation is also a potential concern, particularly upon blast off by way of shedding whilst the shuttle’s main engines fire uphill.

“Ice is a biggie,” stated Wayne Hale, deputy Shuttle manager. “One of the things we were very interested to look at was the performance of the tank and ice growth on the tank.”

The fuelling test consisted of a process involving 500,000 lbs of super-cooled liquid hydrogen and liquid oxygen being pumped into the ET, while also testing how Discovery, her Solid Rocket Boosters (SRBs) and the launch pad itself performed under extremely cold temperatures. Hale remarked that, “The main tank has [now] been provided with new insulation and four heaters to prevent ice formation.

“We had an outstanding day,” Hale went on to announce. “The new external tank performed well, Discovery performed in an outstanding manner and the launch pad performed almost without flaws.”

However, a concern has been noted on a double sensor fault, with a story expanding on this on-going issue to follow.

The deputy Shuttle manager however, did add, “It performed very well, that is heartening news. But that is not all the story.

“We’re doing some testing at Redstone Arsenal and other places regarding the potential for ice to shed off the tank during the ascent and we think there are a number of ways we’re going to come to a good conclusion on that. But there is work remaining before us on that.”

New NASA Administrator Michael Griffin told employees that he was determined to resume the space shuttle program: “All other commitments will flow around what I have to do in order to support the return-to-flight decision.” Griffin – under the authority of President Bush – will give the final clearance for the $6 billion ship to launch.

It seems that in light of this recent testing, Griffin’s determination to see the Space Shuttle fleet return to flight will pay off.

“With the completion of this tanking test, NASA is one step closer to returning the Space Shuttle fleet to flight,” said Michael Kostelnik, NASA’s deputy associate administrator for International Space Station and Space Shuttle Programs.

“Although we have further milestones to complete before we fly, we are proud of the technical advancements we have made the last two years to ensure a safe mission.”

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