Tim Furniss/LONDON
The STS93/Columbia Space Shuttle mission ended on 28 July with a night landing at Kennedy Space Center, Florida. The launch on 23 July - thwarted earlier by an erroneous sensor at T-7s and by lightning - continued to be eventful after it was airborne, coming close to abort (Flight International, 28 July-3 August).
At T+5s, a temporary electrical short circuit caused a drop in power in one of the three fuel cells of the orbiter and forced two of the Space Shuttle Main Engine (SSME) computer controllers to lose power. Two back-up units took over from them.
Liquid hydrogen leaked from a 12.7mm (0.5in)-thick nozzle coolant tube on the SSME, resulting in the engine overheating, which forced it to consume liquid oxygen oxidiser faster than usual.
The engine consumed 1,818kg more oxidiser than normal, forcing two engines to shut down seconds early, leaving the orbiter with an 11km shortfall, which was made up routinely by the first Orbital Manoeuvring System burn.
The five-astronaut crew, which was commanded by Eileen Collins, the first women Shuttle commander, deployed the $1.5 billion, TRW-built Chandra X-ray observatory and its Boeing inertial upper stage (IUS) during the relatively short five-day mission.
The IUS performed as expected and the third of NASA's Great Observatory series was placed into its 3,434 x 72,064km orbit.
The next Shuttle flight, the third to take place this year, will be the STS99/Endeavour Radar Topography Mission scheduled for 16 September.
Source: Flight International
