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LRO a resounding success
DR EMILY BALDWIN
ASTRONOMY NOW
Posted: 22 June 2011


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The Lunar Reconnaissance Orbiter (LRO) has been declared a full mission success by NASA, delivering more than promised and forever changing our view of the Moon.

Launched on 18 June 2009, the $540 million spacecraft's primary objective was to create a comprehensive atlas of the Moon's features and resources necessary to design a future manned lunar outpost.

"LRO was originally conceived to deliver the kinds of information that we need to plan for safe and effective exploration of our Moon," says Michael Wargo, chief lunar scientist for exploration at NASA headquarters. "And that's exactly what we did, in spades. And by doing that, we've fundamentally changed our scientific understanding of the Moon."


Three complementary views of the near side of the Moon, courtesy of LOLA, showing topography (left), surface slope values (middle) and roughness (right). All three views are centered on the relatively young impact crater Tycho, with the Orientale basin on the left side. Image: NASA/Goddard/Massachusetts Institute of Technology.

LRO's general science mission began in September 2010, and between the spacecraft's seven instruments, LRO has returned nearly 200 terabytes of data – enough to fill some 41,000 standard DVDs – via NASA's Communications Network the Near Earth Network, which uses the new 18 metre Ka-band auto-tracking antenna system in New Mexico, as well as the S-band network to collect Doppler tracking data correlating the science data. The Satellite Laser Ranging Network, also a part of the Near Earth Network Project, provides the high precision laser ranging to the LRO spacecraft.

LOLA, the Lunar Orbiter Laser Altimeter, has provided four billion measurements, 100 times more than all previous lunar measurements of its kind combined, yielding information on topography, surface slope values and roughness in greater detail than ever before. Readings include vital information on locations that receive sunlight or are in permanent shadow for the majority of the year; both of which provide useful sites for future solar-powered bases, or sites where water might be frozen, respectively.

LRO's complementary spacecraft mission LCROSS was sent smashing into one such permanently shadowed crater in October 2009, throwing up traces of water ice, as well as many other mineral resources that could be mined to create rocket fuel, for example.

DIVINER, LRO's Lunar Radiometer Experiment, found a record-breaking temperature of -248 degrees celsius (25 kelvin) in one location. DIVINER also measured the temperature of the Moon during the recent lunar eclipse on 15 June, finding an average decrease of 100 kelvin across the surface as the Moon entered Earth's shadow.


The first global daytime and nighttime thermal maps of the Moon are created using Diviner data. The inset shows temperature changes during the LCROSS impact. Image: NASA/Goddard/UCLA.

Meanwhile, LRO's camera LROC has produced a global map of the Moon with a resolution of 100 metres per pixel, with higher resolution images capturing detail at 0.5 metres per pixel. "With this resolution, LRO could easily spot a picnic table on the Moon," says LRO's Project Scientist Richard Vondrak of NASA's Goddard Space Flight Center. Not quite a picnic table, LRO did image the locations where Apollo astronauts walked, placed scientific instruments and drove rovers.

LRO's other instruments – LAMP (Lyman-Alpha Mapping Project), LEND (Lunar Exploration Neutron Detector), CRaTER (Cosmic Ray Telescope for the Effects of Radiation) and Mini-RF (Miniature Radio Frequency) – are between them contributing maps of hydrogen distribution and water ice, and providing details of the lunar radiation environment that could aid in the development of protective technologies to help keep future lunar crew safe.

"Not only did we accomplish all of this during the exploration phase of the mission," says Vondrak, "but two more years of wonderful science are already under way." LRO is now in the hands of NASA's Science Mission Directorate, with ongoing, near continuous acquisition of science data. Funded through to at least September 2012, officials say the technical capability is there to see the spacecraft operate well past this date.