NASA has slowed development of Jet Propulsion Laboratory's Dawn mission, cutting the project's budget, shuffling employees and pushing back the scheduled June 2006 launch date.
Selected as a Discovery Program mission in 2001, Dawn is designed to orbit two asteroids in the belt between Mars and Jupiter - Vesta in July 2010 and Ceres in August 2014.
Chris Russell, the mission's principal investigator and a professor of geophysics at UCLA, said he was shocked by NASA's recent request that Dawn "stand down."
"They basically said that we should slow down or almost stop the development while they decide to take a look at it and make an investigation," Russell said. "They got concerned by the number of problems that they saw that we were having."
Tom Fraschetti, Dawn's project manager at JPL, said the problems largely arose in the development of Dawn's ion propulsion system.