Backgrounder: Brief introduction to LRO/LCROSS mission

WASHINGTON, June 18 (Xinhua) -- NASA's two new lunar probes -- Lunar Reconnaissance Orbiter (LRO), Lunar CRater Observation and Sensing Satellite (LCROSS), lifted off Thursday on a landmark mission to scout water sources and landing sites in anticipation of leading astronauts back to the moon in 2020.

LRO is a robotic mission aimed at creating a comprehensive atlas of the moon's features, finding possible landing sites, identifying available resources, characterizing the radiation environment and testing new technology.

After launch, LRO's journey to the moon will take approximately four days. LRO will then enter an elliptical or "commissioning" orbit. During this period, the LRO spacecraft will be checked out and the scientific instrumentation suite will be activated and tested. After about sixty days, LRO will enter its operational circular polar orbit, 50 km above the moon's surface.

The LRO payload, comprised of seven instruments, will provide vital data to enable a human return to the moon. LRO will spend at least one year in low polar orbit around the moon, collecting detailed information about the lunar surface and environment.

After a year, having collected the data for human mission planning, the spacecraft will be transferred to the Science Mission Directorate and will be used for an extended period of time to address high priority scientific questions identified by the National Academy of Sciences.

Although LRO will remotely sense evidence of resources such as water ice in cold regions of the moon, the LRO launch will also carry another spacecraft, LCROSS, which will directly determine if water ice occurs in an area of permanent shadow near the lunar poles.

LCROSS will search for water ice on the moon by sending the spent upper-stage Centaur rocket to impact part of a polar crater in permanent shadows. It will fly into the plume of dust left by the impact and measure the properties before also colliding with the lunar surface.

Whatever LCROSS discovers about the presence of water, it will increase human knowledge of the mineralogical makeup of some of the most remote areas of the moon -- deep polar craters where sunshine never reaches.

U.S. lunar probes lift off on mission to scout water, landing sites

WASHINGTON, June 18 (Xinhua) -- NASA's two new lunar probes -- Lunar Reconnaissance Orbiter (LRO), Lunar CRater Observation and Sensing Satellite (LCROSS), lifted off Thursday on a landmark mission to scout water sources and landing sites in anticipation of leading astronauts back to the moon in 2020.

The two probes, a powerful lunar orbiter and a smaller spacecraft that will hunt for water ice by crashing into the moon, were launched on an Atlas V rocket at about 5:32 p.m. EDT (2132 GMT) from the Cape Canaveral Air Force Station in Florida.

LRO is a robotic mission aimed at creating a comprehensive atlas of the moon's features, finding possible landing sites, identifying available resources, characterizing the radiation environment and testing new technology.

LCROSS will search for water ice on the moon by sending the spent upper-stage Centaur rocket to impact part of a polar crater in permanent shadows. It will fly into the plume of dust left by the impact and measure the properties before also colliding with the lunar surface.

The launch of the dual probes occurred one month shy of the 40th anniversary of the first lunar footprints.

The 583-million-dollar 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, Florida.

NASA's lunar exploration missions roll to pad for Thursday launch

WASHINGTON, June 17 (Xinhua) -- NASA's Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS) rolled aboard their Atlas V rocket to the launch pad at Cape Canaveral Air Force Station in Florida on Wednesday morning, in preparation for launch on Thursday, NASA said.

The spacecraft left its processing facility at 10:02 EDT (1402 GMT) and arrived at the pad about 35 minutes later.

The spacecraft are scheduled to lift off together on Thursday, June 18, with three attempts possible at 5:12 p.m., 5:22 p.m. and 5:32 p.m.. If launch slips to Friday, June 19, the launch opportunities would be 6:41 p.m., 6:51 p.m. and 7:01 p.m..

The LRO is scheduled for a one-year exploration mission at a polar orbit of about 31 miles, or 50 kilometers, the closest any spacecraft has orbited the moon. Its primary objective is to conduct investigations to prepare for future explorations of the moon.

The LCROSS will search for water ice on the moon by sending the spent upper-stage Centaur rocket to impact part of a polar crater in permanent shadows. The LCROSS will fly into the plume of dust left by the impact and measure the properties before also colliding with the lunar surface.

Launch of space shuttle Endeavor postponed again

Space shuttle Endeavour sits on the launch pad June 17, 2009. (Xinhua/AFP Photo)
Photo Gallery

WASHINGTON, June 17 (Xinhua) -- NASA on Wednesday postponed the launch of space shuttle Endeavor for the second time due to a hydrogen gas leak during fueling.

Endeavor was originally scheduled to lift off on June 13, but was postponed because of a leak associated with the gaseous hydrogen venting system outside the shuttle's external fuel tank.

The system is used to carry excess hydrogen safely away from the launch pad.

Endeavor's 16-day STS-127 mission to the International Space Station will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency's Kibo laboratory.

Astronauts will attach a platform to the outside of the Japanese module that will allow experiments to be exposed to space.

NASA sets new launch dates for space shuttle, LRO and LCROSS

Space shuttle Endeavour crewmembers
(L-R) Chris Cassidy, Tom Marshburn, Tim Kopra and Canadian Space Agency
astronaut Julie Payette listen to trainer and Astronaut Rescue Team Leader
Capt. George Hoggard as he instructs them on driving an M-113 armored
personnel carrier during launch rehearsal exercises at the Kennedy Space
Center in Cape Canaveral, Florida June 2, 2009. (Xinhua/Reuters
Photo)
Photo
Gallery

WASHINGTON, June 15 (Xinhua) -- NASA managers on
Monday scheduled the next launch attempt of space shuttle Endeavour's STS-127
mission for 5:40 a.m. EDT (0940 GMT) on Wednesday. The launch will take place at
NASA's Kennedy Space Center in Florida.

As a result, the Lunar Reconnaissance Orbiter (LRO)
and Lunar Crater Observation and Sensing Satellite (LCROSS) are set to lift off
together aboard an Atlas V rocket on Thursday, June 18. There are three launch
opportunities from Cape Canaveral Air Force Station in Florida -- 5:12 p.m.,
5:22 p.m. and 5:32 p.m.

Endeavour was originally scheduled to lift off on
June 13, but was postponed because of a leak associated with the gaseous
hydrogen venting system outside the shuttle's external fuel tank. The system is
used to carry excess hydrogen safely away from the launch pad.

Endeavour's 16-day STS-127 mission to the
International Space Station will feature five spacewalks and complete
construction of the Japan Aerospace Exploration Agency's Kibo laboratory.
Astronauts will attach a platform to the outside of the Japanese module that
will allow experiments to be exposed to space.

The LRO and LCROSS launch was moved to June 18 to
accommodate Endeavour's June 17 liftoff. If Thursday's liftoff of the LRO and
LCROSS is postponed 24 hours, the launch times Friday are 6:41 p.m., 6:51 p.m.
and 7:01 p.m.. Saturday's opportunities are 8:08 p.m.,8:18 p.m. and 8:28 p.m..

The LRO is scheduled for a one-year exploration
mission at a polar orbit of about 31 miles, or 50 kilometers, the closest any
spacecraft has orbited the moon. The primary objective of the LRO is to conduct
investigations to prepare for future explorations of the moon.

Launching with the LRO is LCROSS, a partner mission
that will search for water ice on the moon by sending the spent upper-stage
Centaur rocket, about the size of a sports utility vehicle, to impact part of a
polar crater in permanent shadows. The LCROSS will fly into the plume of dust
left by the impact and measure the properties before also colliding with the
lunar surface.