The U.S. space agency NASA announced on Monday the reinstatement of the Dawn mission, a previously-canceled project to explore two asteroids.
The mission, named because it was designed to study objects dating from the dawn of the solar system, would send a robotic probe to Vesta and Ceres, two of the largest asteroids orbiting the sun between Mars and Jupiter.
It was initially canceled on March 2 because of technical problems and budget overruns, NASA said.
But the decision was strongly criticized by the mission scientists at a recent conference, and, after further reviews and evaluation, NASA officials said they had regained confidence in the mission.
"We revisited a number of technical and financial challenges and the work being done to address them," said Rex Geveden, the NASA Associate Administrator who led the review.
"Our review determined the project team has made substantive progress on many of this mission's technical issues, and, in the end, we have confidence the mission will succeed."
"There are always pretty tall challenges," Geveden told reporters in a teleconference, "and it looks like Dawn is ready to take those on and beat them."
NASA first approved the Dawn mission in 2001 as part of its low-cost Discovery mission program. Propelled by a novel electric ion engine, the Dawn spacecraft had been scheduled for launch in June 2006.
But technical difficulties and other problems delayed the launch to July 2007, boosting the cost from 373 million to 446 million dollars.
The cost overrun and a 13-month launch delay prompted NASA's March 2 decision to scrap the mission, which came after 257 million dollars had already been spent, the space agency said.
However, after in-depth study of the cost overruns and technical challenges in the mission review, NASA changed its mind, and concluded that the mission should proceed. NASA agreed to reinstate funding and added about $70 million more to cover the project's overrun. Dawn is now scheduled to launch in the summer of next year and it should reach its first target in 2011.
Unfortunately, the funds needed to save the project would prevent other programs from moving ahead, Geveden indicated.
"Sometimes future missions or current missions have to sacrifice," he said.