Chandrayaan Radar Peers Into Lunar Crater

Jan 22, 2009
Frank Morring, Jr. morring@aviationweek.com



A prototype lightweight synthetic aperture radar (SAR) supplied by NASA had generated its first data from the bottom of a permanently dark crater at one of the moon's poles, riding India's Chandrayaan-1 lunar orbiter to test its ability to search for water ice and other volatiles that might help support a human presence.

The Mini-SAR imaged the never-before-seen floor of the south polar Haworth crater. Developed by the Johns Hopkins University Applied Physics Laboratory and the U.S. Naval Air Warfare Center, a Mini-SAR also will fly on NASA's Lunar Reconnaissance Orbiter (LRO), set for launch this spring.

Both instruments will use their positions in lunar orbit to continue investigating the hydrogen signatures detected in the deep polar craters by ground-based radars and orbiters like the Pentagon's Clementine missile defense testbed. Some scientists believe those signatures could originate with material from ancient comets that flowed to the lunar poles and remained preserved in the deep freeze of permanent darkness in deep craters there.

NASA plans to spend "the next few months" calibrating the Chandrayaan-1 Mini-SAR, and may be able to operate it in tandem with the one on LRO. That orbiter also will send its spent upper stage into a dark polar crater so the plume of debris generated can be analyzed for the presence of ice.

Photo: NASA