Friday, November 05, 2010

GLH2 Leak and Foam Crack Delays Shuttle Launch

Sunrise at the Kennedy Space Center today. (NASA)

A cracked piece of foam insulation and a leaking fuel region -- both on the external tank of the space shuttle Discovery -- has forced a three week delay in the start of her final flight.

Today's launch attempt began with the on time start of the fueling of the ship's rust colored external fuel tank at 6AM EDT.

However, nearly two hours into fueling, the launch team discovered a small gaseous hydrogen leak at the Ground Umbilical Carrier Plate (GUCP) on the back side of the large tank.

The GUCP carries the gaseous hydrogen away from the space shuttle to a huge fire burning stand a hundred yards away where it is burned off.

Similar GLH2 leaks occurred twice last year and required several days to remove the plate located on the opposite side of where the shuttle is attached and repair the seal.

Launch pad workers will also investigate "a crack in the external tank foam that developed as super cold liquid hydrogen and liquid oxygen were being drained from the tank," a NASA spokesperson stated today. "The crack did not develop until after the launch attempt was called off."

Work to repair the huge U-shaped foam crack (above image) will be discussed over the next few days.

Following the discovery of the crack during detanking this morning, NASA's Mission Management team elected to delay launch until no earlier than November 30.

NASA had until Sunday and maybe Monday as the last days to launch the spacecraft or face a launch delay until November 30 due to sun angels at Discovery's planned port-of-call -- the International Space Station.

The Sun angels issue, known as beta cutout, will warm the station too much with a shuttle docked due to the orientation the pair would fly. Once docked, the space station turns itself with the help of the orbiter's thrusters so that Discovery's belly is in the direction of travel.

This helps minimize micrometeorites from striking the orbiter's payload bay, glass windows and engine nozzels.

On Monday, NASA hopes to be able to discuss what direction the launch team will move towards as the month decreases in time.

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