English: The LEND is one of seven instruments aboard NASA’s Lunar Reconnaissance Orbiter spacecraft

LEND is a neutron spectrometer similar to another instrument, the High Energy Neutron Detector (HEND) that has been operating around Mars since 2001 on the Mars Odyssey spacecraft. The neutrons measured by these instruments are formed by cosmic-ray interactions with the planetary surface. If hydrogen is present, it will change the energy spectrum of those neutrons, providing quantitative information on hydrogen distribution. Unlike HEND, LEND is designed with a passive collimator that provides high spatial resolution (10 km FWHM) of neutron emission at the lunar surface. No other neutron instrument with this imaging capability has ever flown in space.

The Lunar Exploration Neutron Detector (LEND) will create high-resolution maps of hydrogen distribution and gather information about the neutron component of the lunar radiation environment. LEND data will be analyzed to search for evidence of water ice near the moon’s surface. LEND was developed at the Institute for Space Research in Moscow.