WASHINGTON, June 23 (Xinhua) -- The Lunar Crater Observation and Sensing
Satellite (LCROSS) successfully completed its most significant early mission
milestone Tuesday with a lunar swing-by and calibration of its science
instruments, NASA said in a press release.
With the assist of the moon's gravity, LCROSS and its attached Centaur
booster rocket entered into polar Earth orbit at 6:20 a.m. PDT (1220 GMT). The
maneuver will put the spacecraft and Centaur on course for a pair of impacts
near the moon's south pole on Oct. 9.
"The successful completion of the LCROSS swing-by proves the science
instruments are functioning as expected. It is a testament to the hard work and
dedication of the entire team," said
Dan Andrews, LCROSS project manager at NASA's Ames Research Center at
Moffett Field, California.
"We are elated at the results from the maneuver and eagerly anticipate the
impacts in early October," he added.
During its swing by the moon, the spacecraft's instruments were turned on
and calibrated by scanning three sites on the lunar surface. These sites were
the craters Mendeleev, Goddard C and Giordano Bruno. They were selected because
they offer a variety of terrain types, compositions and illumination conditions.
The spacecraft also scanned the lunar horizon to confirm its instruments are
aligned in preparation for observing the Centaur's debris plume.
"Each instrument returned good data that the science team will spend the
next few weeks analyzing," said Anthony Colaprete, LCROSS project scientist at
Ames. "These data will ensure we are as prepared as possible for monitoring and
interpreting data we receive during impact."
LCROSS and its attached Centaur upper stage rocket are now in a long,
looping polar orbit around Earth and the moon. Each orbit will be roughly
perpendicular to the moon's orbit around Earth and take about 37 days to
complete. Before impact, the spacecraft and Centaur will make approximately
three orbits.
LCROSS and the Centaur separately will collide with the moon at
approximately 7:30 a.m. EDT (1130 GMT) on Oct. 9, creating a pair of debris
plumes that will be analyzed for the presence of water ice or water vapor,
hydrocarbons and hydrated materials.
The spacecraft and Centaur are targeted to impact the moon's south pole
near the Cabeus region. The exact target crater will be identified
30 days before impact, after considering information collected by NASA's
Lunar Reconnaissance Orbiter (LRO) and observatories on Earth.
Nine hours before impact, about 54,000 miles (86,400 km) above the surface,
LCROSS and the Centaur will separate. LCROSS will spin 180 degrees to turn its
science payload toward the moon and fire thrusters to create distance from the
Centaur. The spacecraft will observe the flash from the Centaur's impact and fly
through the debris plume. Data will be collected and streamed to Earth for
analysis. Four minutes later, LCROSS also will impact, creating a second debris
plume.
LRO and LCROSS lifted off on June 18 on a landmark mission to scout water
sources and landing sites in anticipation of leading astronauts back to the moon
in 2020.