Tim Furniss/LONDON
NASA HAS FORMED an independent panel to review the loss of the Italian Tethered Satellite (TSS 1R) from the Space Shuttle Columbia during the STS75 mission on 26 February. A report into its findings will be made available within 70 days.
"Given the public investment in the Tethered Satellite, it is important to find out what went wrong...to do any less would be a disservice to the American and Italian people," says Wilbur Trafton, NASA's acting associate administrator of the Office of Space Flight.
The $440 million, 1.6m-diameter, 518kg TSS 1R reached 19.7km from the Columbia, 5h after it began its deployment at the end of a 2.54mm-thick, 20.7km-long braided copper, nylon and Teflon tether. Deployment - delayed 24h because of three computer problems - began at a speed of 0.012m/s, increased to 2.2m/s and was at 1m/s when the problem occurred.
The TSS was successfully demonstrating its primary flight objective - planned to last two days - of generating 3,500V through the tether (Flight International, 21-27 February), when the tether snapped suddenly.
The satellite and its snaking tether accelerated at a speed of 24m/s into a higher orbit, from which the satellite will re-enter the atmosphere in about 30 days.
The Columbia crew reported that the end of the remaining tether, in its 12m-tall deployment mast, looked singed and discoloured, suggesting that an electrical discharge may have been involved, caused by the outer layers of the tether being worn, possibly, during the unreeling and exposing the copper wire.
The spectre of the Space Shuttle programme's first return-to-launch-site abort hit the Columbia at T+15s after its launch from the Kennedy Space Center in Florida on 22 February (Flight International, 3-9 January). The caution-warning alarm was sounded when an errant gauge indicated a 55% loss of thrust in the left-hand Space Shuttle main engine.
Source: Flight International
