Posted: Sat, Mar 8, 2003, 1:02 PM ET (1802 GMT)
Scientists have found a new comet to send ESA's Rosetta spacecraft to, primarily because no other qualified comets are available, British media reported Friday. The BBC and New Scientist reported that scientists have settled on comet 67P/Churyumov-Gerasimenko ™ aka "Chury" ™ to send Rosetta to, with a launch scheduled for February 2004. Rosetta was scheduled to launch in January on a flight to another comet, Wirtanen, but investigations into the loss of an Ariane 5 in December caused the launch to be delayed beyond the end of the launch window in late January. Scientists have been looking at alternative comets Rosetta could fly to, but restrictions on the mission essentially ruled out any other comet but Chury. Those restrictions include a launch by mid-2005 and a comet rendezvous near the orbit of Jupiter, so that the comet is far enough from the Sun its surface will be cold and inactive enough to permit a safe rendezvous and landing. It would be possible for Rosetta to go to Wirtanen, but would require a trajectory that would take the spacecraft around Venus, too close to the Sun to permit safe operations. Chury is several times larger than Wirtanen, and its correspondingly stronger gravity will require revisions to Rosetta's software to permit a safe approach and landing when it arrives in 2014.

Related Links:

•  New Scientist article
•  BBC article