Will Study Moon From Crust To Core
NASA's twin lunar Gravity Recovery and Interior Laboratory
(GRAIL) spacecraft lifted off from Cape Canaveral Air Force Station
in Florida at 9:08 a.m. EDT Saturday to study the moon in
GRAIL-A is scheduled to reach the moon on New Year's Eve 2011,
while GRAIL-B will arrive New Year's Day 2012. The two
solar-powered spacecraft will fly in tandem orbits around the moon
to measure its gravity field. GRAIL will answer longstanding
questions about the moon and give scientists a better understanding
of how Earth and other rocky planets in the solar system
"If there was ever any doubt that Florida's Space Coast would
continue to be open for business, that thought was drowned out by
the roar of today's GRAIL launch," said NASA Administrator Charles
Bolden. "GRAIL and many other exciting upcoming missions make clear
that NASA is taking its next big leap into deep space exploration,
and the space industry continues to provide the jobs and workers
needed to support this critical effort."
The spacecraft were launched aboard a United Launch Alliance
Delta II rocket. GRAIL mission controllers acquired a signal from
GRAIL-A at 10:29 a.m. GRAIL-B's signal was eight minutes later. The
telemetry downlinked from both spacecraft indicates they have
deployed their solar panels and are operating as expected.
"Our GRAIL twins have Earth in their rearview mirrors and the
moon in their sights," said David Lehman, GRAIL project manager at
NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "The
mission team is ready to test, analyze and fine-tune our spacecraft
over the next three-and-a-half months on our journey to lunar
The straight-line distance from Earth to the moon is
approximately 250,000 miles (402,336 kilometers). NASA's Apollo
moon crews needed approximately three days to cover that distance.
However, each spacecraft will take approximately 3.5 months and
cover more than 2.5 million miles (4 million kilometers) to arrive.
This low-energy trajectory results in the longer travel time. The
size of the launch vehicle allows more time for spacecraft checkout
and time to update plans for lunar operations. The science
collection phase for GRAIL is expected to last 82 days.
"Since the earliest humans looked skyward, they have been
fascinated by the moon," said GRAIL principal investigator Maria
Zuber from the Massachusetts Institute of Technology in Cambridge.
"GRAIL will take lunar exploration to a new level, providing an
unprecedented characterization of the moon's interior that will
advance understanding of how the moon formed and evolved."
JPL manages the GRAIL mission. It is part of the Discovery
Program managed at NASA's Marshall Space Flight Center in
Huntsville, AL Lockheed Martin Space Systems in Denver built the
spacecraft. Launch management for the mission is the responsibility
of NASA's Launch Services Program at the Kennedy Space Center in