Key shuttle review on tap at KSC

A two-day review considered crucial to clearing shuttle Discovery for flight will begin at Kennedy Space Center this afternoon as NASA continues preparations for a planned July 1 launch.

NASA engineers will brief senior managers on the results of analyses carried out to determine whether the shuttle's redesigned external tank will shed pieces of foam insulation large enough to cause severe damage to the orbiter Discovery.

NASA managers then will decide whether the probability of such a foam strike is remote enough to be deemed an acceptable risk, a finding that would keep plans for a July 1 launch intact.

NASA never will be able to completely prevent foam from falling off the 15-story tanks in flight, managers say, and the agency fully expects Discovery's tank to shed small pieces of insulation. The intent of the post-Columbia redesign is to halt the loss of foam chunks large enough to cause critical damage to an orbiter.

Analyses to date has shown there is a chance so-called Ice Frost Ramps could shed foam large enough to do severe damage to an orbiter's heat sheilding, which protects the ship and its astronauts from intense heat encountered during atmospheric reentry.

The ramps are manually applied blocks of foam designed to keep ice from building up on metal brackets that secure pressurization lines to the outside of the tank. Managers in late April decided the probability of a catastrophic foam hit from one of 34 Ice Frost Ramps was low enough to proceed with the planned July launch without further modifications.

The two-day review is expected to wrap up about mid-afternoon Wednesday.