NASA gives ramp rationale

by Chris Bergin

During a press briefing today, NASA gave its reasons for pressing ahead with the expected July launch of Shuttle Discovery on STS-121.

Despite concerns raised during yesterday’s PRCB, managers made the decision to go ahead with the second test flight, full in the knowledge that more work will have to continue on reducing foam liberation from the External Tanks.

Following the removal of the PAL ramp from all External Tanks – starting with ET-119, which will fly with Discovery this summer – extra work has focused on the ice/frost ramps, which line the outside of the tanks.

Wind Tunnel testing has shown that some liberation will be possible from these ramps, although computations and tests show it is expected to be minimal.

MSFC (Marshall Space Flight Center) was the more ardent in their recommendation that a delay should be placed on STS-121, while extra evaluations and modifications are made to the ramps, mainly the reduction to the foam surface that make up the individual ramps.

‘We reviewed that yesterday, work from hundreds of people, and we reached a conclusion that it was a mixed conclusion,’ noted Shuttle manager Wayne Hale, confirming the split opinion that came out of the PRCB.

‘There is further work we’d like to do on the tank. Yesterday we worked on the ice/frost ramps.’

However, the recommendation to carry out further work on the ramps was rejected, as NASA pushes towards the July launch date, an opportunity that stretches from July 1 to 23.

Work still has to be completed, even while Discovery is readied for launch. NASA hope to finally conclude their position at the Flight Readiness Review (FRR) which takes place next month.

‘We’re working towards the July launch opportunity, we have a huge amount of work ahead of us, but I think we have a good plan,’ said Shuttle manager Wayne Hale.

Further, expanded articles will follow shortly.


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