Technicians at Pad 39A at the Kennedy Space Center, Florida, began unprecedented repair work to the solid- rocket boosters of the Space Shuttle Endeavour on 18 August.

Working inside the nozzles of the boosters, technicians are replacing the insulating material protecting the nozzle O-ring joints with a new material. Seven sets of solid-rocket boosters will undergo this work and the new material will be introduced on future production (Flight International, 9-15 August).

The O-rings had been damaged by hot gas which penetrated tiny air pockets in the material during two previous missions. The Endeavour STS69 mission is now unlikely to be launched before the middle of September, possibly delaying follow-on missions, including the second planned visit by the Space Shuttle Atlantis to the Russian Mir 1 space station in October, by the STS74.

The mission scheduled to go before the Atlantis - the STS73/US Microgravity Laboratory 2 mission aboard the Space Shuttle Columbia - has also run into a technical hitch. Its three main engines were to have been fitted with the new performance-boosting Pratt & Whitney liquid-oxygen turbopump, which was given its debut in July on one engine of the STS70/Discovery.

Following the discovery of a faulty seal after an engine test, only two of its engines will use the turbopump. Two engines have been cleared for take-off, but a third has been pulled off the flight for checks (Flight International, 3-9 May).

Brewster Shaw, NASA Shuttle operations director, has resigned and will leave in November.


Source: Flight International