Posted: Mon, Feb 19, 2001, 12:58 PM ET (1758 GMT)
Engineers are looking into a problem with multiple attitude-control thruster firings on NASA's Stardust spacecraft. The problem, reported in a weekly status report published Friday and in additional detail by Spaceflight Now over the weekend, appears when the spacecraft reaches the limits of a "deadband", a range of attitudes the spacecraft can freely drift through. The spacecraft is designed to fire its thrusters to move away from the deadband limit, but apparently the thrusters are fired multiple times, even after the spacecraft is moving in the right direction. The problem is considered minor now, but over time could become a more serious issue as the spacecraft consumes extra propellant. Other than the problem, the spacecraft is working normally: a mid-course correction burn planned after last month's Earth flyby was cancelled after it was deemed unnecessary. The spacecraft, launched in 1999, will fly by the comet Wild-2 in 2004 and collect cometary dust samples before returning those samples to Earth in 2006.
