The foam that detached on liftoff and led to the space shuttle Columbia disaster last year has been removed from redesigns of the fuel tanks that launch shuttles into space, NASA officials said.
NASA approved a redesign that installs heaters in place of some of the foam, which is applied to the fuel tanks as a shield against ice buildup, according to a statement released by the space agency on Monday. Foam will still cover most of the tanks, but heaters will be used in parts of the bipod area, where the fuel tank attaches to the spacecraft.
"This is a fix that really gets to the root of the technical problems that caused the loss of Columbia," said Michael Kostelnik, a NASA deputy associate administrator.
Workers at a NASA facility in New Orleans have begun retrofitting the tank that is set to be used next year in the first shuttle mission since the Feb. 1, 2003 Columbia disaster, said Harry Wadsworth, a spokesman for Lockheed Martin, the facility's main contractor.
The tank is expected to be ready for shipping to Kennedy Space Center in Florida by late October, Wadsworth said. The tank will then be attached to the shuttle Discovery, which is set for the first shuttle mission since Columbia, in March or April.
An investigation into the Columbia disaster determined that a briefcase-sized chunk of foam flew off the bipod area of the external tank during liftoff and struck the shuttle's left wing, creating a hole. Searing gases entered the hole when the shuttle re-entered the atmosphere, the investigators found, leading to its destruction over Texas and the deaths of all seven astronauts.
Ice forms on the outside of the tanks because they are filled with liquid fuel that reaches temperatures as low as minus 423 degrees Fahrenheit.
