Despite
facing looming technical problems with a launch vehicle and assembly crane,
NASA officials said in a telephone conference today that they are intent on a
July 7 launch of the Dawn mission.
If the
launch vehicle and assembly crane aren't repaired, however, the U.S. space agency faces a "traffic jam" into space that could cost around $25 million.
Rough
weather caused mechanical difficulties in components attached to the launch
vehicle during its transportation, a NASA official said.
Todd May,
the deputy associate administrator for programs at NASA headquarters in Washington, said both the asteroid-belt-exploring Dawn and Mars-bound
Phoenix missions are very sensitive to launch changes. To reach their
targets, each
must leave Earth within a defined window of time.
"They're
both planetary, so they have limited launch windows," May said. "It's a hard
window constraint to get (Phoenix) off by Aug. 25," he continued, so any
movement of the Dawn launch window could also interfere with Phoenix's
launch—as well as the STS-118
shuttle mission, expected to launch on Aug. 7.
In
addition to the launch problems, one of Dawn's solar panels was damaged while
at NASA's Kennedy Space Center during processing. On June 18, NASA said
technicians repaired damage, which was caused by an "errant tool."
The Dawn
mission team will decide on July 2 whether they will launch Dawn July 7. May
explained that scrubbing the launch would cost around $25 million, but said the
team is moving "full steam ahead" for a launch next Saturday.
"To some
extent there's no looking back," he said of an agreement to launch. "We will be
watching the weather closely and by that time have the launch vehicle issues
out of the way."
NASA hopes
to use Dawn to investigate two
leftover chunks of the early solar system. Ceres was once called the
largest asteroid and is now re-labled as a dwarf planet. The other target:
asteroid Vesta. Both objects reside in the asteroid belt between Mars and
Jupiter.
The two
bodies share similar properties with Earth, and astronomers believe Ceres, at
about 590 miles wide, might harbor
ice beneath its dusty shell. Vesta is a mostly dry rock roughly 330 miles
in diameter.
If all goes
as planned, the spacecraft will first orbit Vesta in 2011 and then Ceres in
2015. At each stop, Dawn will collect detailed information and photographs of
each rock, such as their shape, size, composition and even clues to their
internal histories. Scientists think such information about Earth's
asteroid-belt cousins could reveal clues as to how the solar system formed.
advertisement
