Logistical Difficulties, Weather To Blame

We're not saying NASA's Dawn spacecraft is cursed... but we're sure the agency will be quite relieved to see the trouble-plagued space probe finally leave the launch pad. NASA announced Friday the launch of Dawn -- at last word, planned for Sunday -- has now been rescheduled to no earlier than Monday, July 9.

The new delay is due to difficulties with a downrange telemetry aircraft, according to NASA, and the availability of a tracking ship. Also, Friday's weather forecast raised the possibility that the loading of propellants aboard the Delta II rocket's second stage might not be completed in time to support a launch before Monday.

The launch window for Monday is 1556 to 1625 EDT. According to weather forecasts, there is a 40 percent chance of unfavorable conditions for launch -- better than the 60 percent chance of poor weather forecast for Sunday.

This is far from the first time the Dawn mission has hit a snag. As Aero-News reported, NASA cancelled the mission outright in March 2006 -- after delaying it in January -- citing cost overruns, budgetary woes, and technical faults that plagued the project for years. However, the agency later granted Dawn a reprieve, after receiving several protests from the scientific community.

Late last month, NASA moved the launch date to early July, after a crane used to stack segments of the Delta II booster broke down. A worker's wrench also fell on the spacecraft's solar panel during a procedure to prepare the spacecraft for spin-balance testing, though it did not damage any cells.

Once it is eventually launched, Dawn will visit the asteroids Ceres and Vesta, contained in an asteroid belt between Mars and Jupiter. They are two of the largest such bodies in the solar system, and scientists hope the two heavenly bodies will reveal clues about the formation of the solar system.

FMI: www.nasa.gov/dawn