Columbia back in orbit with same crew

Halsell and his crew spent only four days in orbit last time. NASA aborted the mission because of alarming voltage swings in one of the fuel cells, which generate electricity. The fuel cell was replaced after Columbia returned to earth on April 8, and the same crew was reassembled for another go at it.

The same 33 laboratory experiments are flying as before: fire, plant, crystal and metal studies that resemble the kind of research to be conducted on the future international space station.

Engineers still do not know why the fuel cell malfunctioned, although it’s now apparent that the shuttle could have remained safely in orbit, said shuttle program manager Tommy Holloway.

Columbia’s fuel cells appeared to be working well this time, but one of three hydraulic units used to steer the spacecraft during landing exhibited a pressure drop once the shuttle reached orbit and alarms went off.NASA launch manager Loren Shriver said it did not appear to be much of a problem in any event, the hydraulic units are not needed again until the shuttle returns to earth on July 17.

This is the first time in 36 years of US human space flight that a crew has flown in space together more than once, and is the quickest return to space for any American — within only 84 days. Even if it had wanted to, NASA could not have sent Columbia to Russia’s crippled space station Mir as only space shuttle Atlantis is equipped with the necessary docking device.

Columbia’s four scientists plan to set 144 small fires in enclosed chambers during the flight to study the behaviour of flames in weightlessness. The dangerous fire aboard Mir in February highlighted the need for such research.It is costing NASA between $ 60 million and $ 70 million to repeat the mission.