Weather Keeps Probe On Pad Monday; Window Runs Out Soon

NASA has scheduled the space probe Dawn for its much-delayed launch this Thursday. Dawn will be sent on an eight-year mission to unlock the secrets of the solar system and how it was born.

Initial exploration targets are Ceres and Vesta, the two largest asteroids orbiting the sun, in the asteroid belt between Mars and Jupiter. Lift-off is scheduled between 0720 and 0749 Thursday, after clouds prevented NASA from fueling the probe's launch booster this weekend.

Dawn is scheduled to spend eight months orbiting Vesta in October 2011, then move on to a rendezvous with Ceres in February 2015 -- traveling a total distance of over three- billion miles.

As ANN has reported, Dawn has become somewhat a poster child for mission delays.

The mission was cancelled in 2003, then reinstated the following year. NASA then announced the mission was in "stand down mode" in the fall of 2005, called it "indefinitely postponed" in January 2006, then cancelled it two months later blaming budget overruns and, of all things, delays. Then, after howls of protest from the scientific community, Dawn was officially back on less than a month later.

The probe was scheduled for a launch this year on June 20... but delays getting parts slipped that to June 30. A broken crane, competing launch priorities, and a wrench dropped into the spacecraft by a worker conspired to delay the mission further, and here we are.

If Dawn isn't launched in the next few weeks, the asteroids which are its primary exploration targets will have moved out of its range.

FMI: http://dawn.jpl.nasa.gov