In the ten years since its launch from Cape Canaveral, NASA’s Dawn spacecraft has orbited the two largest worlds in the asteroid belt and overcome defective components that threatened to derail the mission on its 4 billion-mile voyage, discovering unexpectedly rich geologic tapestries suggesting both destinations have a watery past.
The roughly $500 million project has made history, becoming the first spacecraft to orbit two different objects other than the Earth and the moon, and making the first up-close surveys of the dwarf planet Ceres and the giant asteroid Vesta, which rank No. 1 and No. 2 among the biggest objects in the asteroid belt, a region between the orbits of Mars and Jupiter.
“Dawn has exceeded everybody’s expectations, and certainly mine,” said Carol Raymond, Dawn’s deputy principal investigator from the Jet Propulsion Laboratory in Pasadena, California. “I think it’s been an exceptional mission from so many different perspectives. Certainly, the fact that we flew to and orbited two objects in the main asteroid belt, the two most massive objects in the main belt, is a feat in and of itself.”
Spaceflight Now members can read a transcript of Carol Raymond’s interview.
The mission almost never made it to the launch pad.
Cost overruns and difficulties with Dawn’s electric propulsion system — a set of three ion engines using electricity and xenon gas to produce thrust — prompted NASA to cancel the mission in March 2006. The space agency reinstated the mission less than a month later after an appeal from managers at JPL.
NASA selected the Dawn mission in 2001 from a list of proposals submitted by scientists. Then slated for launch in 2006, Dawn joined NASA’s Discovery line of cost-capped missions exploring the solar system, a program that has included the Mars Pathfinder rover mission…