Nearly 40
years after humans first set foot on the lunar surface, NASA is gearing up to
go back with the planned launch today of two unmanned scouts, the robotic vanguard
for the first U.S. return to the moon in a decade.
An Atlas 5
rocket is poised to launch the two probes, a powerful
lunar orbiter and a smaller spacecraft that will hunt for water ice by
crashing into the moon, at about 5:12 p.m. EDT (2112 GMT) today from the Cape
Canaveral Air Force Station in Florida. The mission, NASA hopes, will lay the
foundation for its plan to return astronauts to the moon by 2020.
"We're
getting ready to take longer strides. To leave the shallows, once again, and
step into deeper waters of what President Kennedy called the new ocean of
space," said Todd May, manager for NASA's Lunar Precursor Robotic Program.
"The first island we plan to explore is the moon itself, our
nearest neighbor."
The $583
million mission has been delayed since October 2008 and was slated to launch on
Wednesday. But NASA opted to delay the flight by one more day to allow the
space shuttle Endeavour to try and launch after a hydrogen gas leak thwarted its
initial attempt. The leak reappeared and the shuttle remains on Earth at the
nearby Kennedy Space Center in Cape Canaveral, Fla.
Return to
the moon
Shuttle
delay aside, NASA's two new lunar spacecraft are ready to fly.
They are
the first U.S. moon probes since 1998's Lunar Prospector, though China, Japan
and India have sent lunar
probes in recent years. Today's launch is also the inaugural flight of
NASA's long-term exploration vision of sending astronauts back to the moon to
stay.
During
NASA's Apollo lunar landing missions, 12 astronauts explored six equatorial
regions on the moon for days at a time. When astronauts return, NASA plans to
send them to unexplored regions, like the tantalizing south pole, for months at
a time. But to do that, scientists need to know more about the long-term
environment future lunar astronauts will face.
The new
mission's flagship is NASA's Lunar Reconnaissance Orbiter (LRO), a satellite the
size of a Mini Cooper car with a roof rack that will build new maps of the moon
in unprecedented detail to seek out future landing zones and resources for
astronauts.
"Probably
most important to all of us is to find safe landing sites, but we also need to
find interesting landing sites," said Craig Tooley, NASA's LRO project manager.
LRO is
carrying seven instruments to map the moon from a 31-mile (50 km) orbit,
measure its temperature extremes and study its radiation environment using a
special plastic designed to mimic human tissue. It will spend a year studying
the moon to aid future astronaut missions before NASA turns it over to a
science team for a potential years-long extension.
Hunting
moon water
Riding
piggyback on LRO's Atlas 5 rocket is the Lunar CRater Observation and Sensing
Satellite (LCROSS), a smaller probe added because there was extra room on the
booster. LCROSS is NASA's
double whammy for the moon to dredge up any water ice hidden in permanent
darkness at the lunar south pole.
Past
missions have found ample traces of hydrogen suggesting water ice may lurk in
the moon's shadowed craters, but NASA hopes LRO and LCROSS will be able to find
direct evidence of the wet resource.
There are
no guarantees the water ice is actually there, or what kind of shape it is in,
mission managers said. Some observations predict ice rinks of the stuff, while
others suggest the ice is in blocky chunks or buried, if it is there at all, they
added.
"That
illustrates the importance of our mission," said Daniel Andrews, NASA's project
manager for the LCROSS probe. "Let's go see what it is."
It costs
$50,000 a pound to send anything to the moon, so finding water ice or permanent
regions of sunlight for solar power stations could be vital to help support
future moon bases, NASA officials said.
Unlike LRO
- which should take just four days to reach
the moon - the smaller LCROSS will spend months attached to the Atlas 5
rocket's large Centaur upper stage, which it will ultimately steer into a steep
collision course that will slam into a shadowed crater at the moon's south pole
at about 5,580 mph (8,980 kph). After studying the crash from afar, LCROSS will
fly through the crash plume and make its own death dive minutes later.
LRO, the
Hubble Space Telescope and other assets in space and skywatchers on Earth are
expected to observe the lunar smackdown, which is slated to occur in early
October. The final collision date depends on when the mission launches. The
target crater will be decided about a month before impact.
"The
spacecraft is here now, we're ready to go for launch and the science team is
ready," said LRO project scientist Richard Vondrak.
LCROSS is
following in the footsteps of many spacecraft that have intentionally hit the
moon. Earlier this month, Japan's Kaguya lunar probe ended its year-long
mission with a moon crash. China's Chang'e 1 probe did the same earlier this
year.
Multiple
chances
The Atlas 5
rocket carrying the LRO and LCROSS probes actually has three chances to blast
off today. NASA is targeting the first opportunity, but two other one-second
windows are available at 5:22 p.m. EDT and 5:32 p.m. EDT, respectively.
If the
rocket is unable to launch today, NASA can try again Friday at 6:41 p.m. EDT
(2241 GMT). Two other Friday opportunities are available in 10-minute intervals
after the first target. The mission's flight window closes on Saturday, after
which the two lunar probes would have to wait another two weeks before the moon
returns to a position that is favorable for launch.
After
months of delay, LRO and LCROSS researchers said they are chomping at the bit
to get started.
"We were
ready to go last fall," Vondrak said, adding that the delays were frustrating
at times. "We're eager, we're ready to go."
NASA
will broadcast the launch of its new moon probes on NASA TV beginning at 2:00
p.m. EDT (1800 GMT). Click
here for live launch coverage and SPACE.com's NASA TV feed.
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