March Space Shuttle Launch Delayed Because of Hail Storm

Next month's launch of the Space Shuttle Atlantis has been postponed by NASA due to damage suffered in a hailstorm, mission managers announced Tuesday. The launch window was to have been from March 15 until March 25.

The shuttle was caught on the launch pad, says N. Wayne Hale Jr., the shuttle program manager, which caused "the worst damage we have even seen" to the external fuel tank's foam insulation. There were thousands - perhaps as many as 7,000 - of tiny divots on the top of the tank. While most of the rest of the shuttle was protected by part of the launch pad itself, the fuel tank extends far above the structure.

In addition, three ice-frost ramps on the upper part of the tank were damaged in the wind gusts that went as high as 62 miles per hour.

"This was large, wind-driven, damaging hail," says Hale. "We have had hail a number of times in the past, hail is not unusual in Florida ... But usually the hail is quite small and rarely causes damage."

There were also a couple dozen blemishes on the left wing of the shuttle, but no serious damage has yet been detected. Any light damage would require cosmetic repairs only, although further testing will of course be performed.

And although the estimated 7,000 divots seems incredibly high, John Chapman - manager of the external tank project office - says far fewer than that would require actual repair. Some shallow divots may be sanded smooth, while others will be filled with pourable insulation and sanded smooth.

The foam on the external fuel tank has been a source of worry since the beginning of the shuttle program. Foam can fall off during lift-off and damage thermal tiles and panels which protect the shuttle on re-entry. In February, 2003, the Space Shuttle Columbia and the seven crew members aboard were lost after insulating foam struck the left wing just after lift-off.

Shuttle Program director Hale said, "we do not believe we can make the launch window for the March launch of Atlantis." The shuttle will have to be rolled back to the hanger for repairs. The planned mission was a construction visit to the International Space Station. The next earliest opportunity to visit the Space Station will be in late April, after a Russian Soyuz vehicle visits.

Sources:

www.nytimes.com/2007/02/28/science/space/28hail.html
www.spaceflightnow.com/shuttle/sts117/070227delay/