What Happens to Insulation Foam at Mach 23?

Stardate 4318.0

This has been an interesting on-going debate for some time. I do not profess to know the technical details about the make-up or placement of the insulating foam on the booster rockets and fuel tanks for the Shuttle. However, I do know that when they are travelling at 23 times the speed of sound, things tend to be a little shaky, and while still in the atmosphere, probably under tons of stresses that most of us simply cannot comprehend.

That being said, the media is really playing this one out. NASA has a culture of safety first, which obviously is essential in their line of business. It is proven by the cancelled launch a few weeks ago. Now they are adamant after studying all of the footage that the foam piece that came off did NOT hit the Discovery at all. This is obviously great news, though I believe the astronauts are goign to check over the shuttle for damage. They are currently docked with the International Space Station, transferring 15 tons of supplies there.

This is the statement from Administrator Griffin from NASA on the Foam Shedding:

RELEASE: 05-207

Statement on Foam Shedding From External Tank

NASA engineers are evaluating the loss of a large piece of insulation foam from the Space Shuttle Discovery’s external fuel tank during Tuesday's launch. Based on initial assessments, the foam -- which appears to measure approximately 24 to 33 inches long, 10 to 13 inches wide and 2-1/2 to 8 inches thick -- was seen by high-resolution camera equipment added to the Shuttle system after the loss of Columbia in 2003. The accident was caused by foam from the external tank hitting the orbiter during launch.
There was no indication the piece of foam sighted Tuesday caused any damage to Discovery. The Shuttle will undergo further inspection beginning Thursday to check for any significant damage to the orbiter.
"As with any unexpected occurrence, we will closely and thoroughly evaluate this event and make any needed modifications to the Shuttle before we launch again," NASA Administrator Michael Griffin said. "This is a test flight. Among the things we are testing are the integrity of the foam insulation and the performance of new camera equipment installed to detect problems. The cameras worked well. The foam did not.”
Discovery’s seven crew members are being updated with the latest ground team analysis of the foam loss and are continuing to take part in the inspection process.
For the latest information about the STS-114 mission, visit:
http://www.nasa.gov/returntoflight

So now we can look at how the foam is applied to the tanks...

Workers at Michoud Assembly Facility in New Orleans have transferred
External Tank 120 -- the Space Shuttle External Tank slated for the launch of
the orbiter Discovery next spring -- into the facility's vehicle assembly
building. The tank is erected vertically so that foam insulation can be applied
on the liquid hydrogen tank-to-intertank flange area, a tank structural
connection point. The foam will be applied with an enhanced finishing procedure
that requires two technicians, a new mold-injection procedure to the intertank's
ribbing and real-time videotaped surveillance of the process. The foam was
removed from all existing tanks when the intertank area was identified as a
potential debris-shedding source following the loss of the Space Shuttle
Columbia and her crew on Feb. 1, 2003.

Interesting stuff. So they apply the foam in New Orleans and then transfer the tanks to the Kennedy Space Center. This transfer by barge takes 5 or 6 days and I suppose it is thouroughly inspected upon arrival.

This led to design changes to eliminate most of the peeling foam and to control ice on the tank. The changes include new ways of applying the foam insulation, the addition of heaters at key points to prevent the formation of ice before launch, and adding cameras that can monitor the outside of the tank during launch.

"We can never completely eliminate foam coming off the tank," Coleman said Tuesday. But she said tests suggest that any debris that does fly free will not cause damage like that which destroyed Columbia.

They seem to accept that this will not be a foolproof method. Though they have made extensive alterations int he method of applying the foam and also by adding heaters to help prevent icing. The cameras are key in monitoring the entire launch and flight process, so I think given the chance, everything is cool. It could have been a freak accident. Who knows.