Monday, October 27, 2008

Spudis flies with Chandrayaan

Noted planetary geologist Paul Spudis has been named as Principal Investigator for one of two American instruments on their way to the Moon on-board Chandrayaan 1.

The Indian Space Research Organisation's (IRSO) Lunar orbiter passed a 150,000 km Earth orbital apogee, Sunday, already higher than any spacecraft launched by India. Eight nations are participating in a suite of eleven remote sensing instruments on Chandrayaan's mission.

Chandrayaan 1 was successfully launched from Sriharikota, on the southeastern coast of the Sub-Continent, October 22.

Spudis is the immediate-past director of the USRA's NASA-chartered Lunar and Planetary Science Institute in Houston.

Spudis is now PI for the team, headed by Johns Hopkins Applied Physics Research Laboratory and the Naval Research Laboratory, that designed and built the Mini Synthetic Aperture Radar (MiniSAR), imaging radar to map the Lunar poles. MiniSAR will map the permanently-shadowed abyssal craters and valleys at the highest lattitude, in search of water ice and other volatiles.

"This has been a controversial area of investigation for the last decade," explained Lunar and Planetary Institute Director Dr. Stephen Mackwell, "The inclusion of the MiniSAR instrument in the Chandrayaan-1 mission will allow us to collect information on these deposits by mapping them from an instrument in lunar orbit - a first in the exploration of the moon."

U.S. missions Clementine (1994) and Lunar Prospector (1998) both detected the unique signature of Hydrogen, in and around both Lunar poles, with Neutron detectors designed to separate elemental signatures resulting from the spillation of Cosmic Rays breaking about on and immediately below the Moon's surface.

The public release, last week, of images inside Shakelton Crater, taken from the Terrain Camera on-board Japan's Kaguya reportedly eliminated the likelihood of ice at the Lunar poles, but most planetary scientist were not surprised by the images. Few were expecting any water ice there to be immediately visible, in the form of snow or a frozen pond. Most believe what volatiles or water ice there might be at the Lunar poles to be buried or well-mixed with dusty regolith.

Hydrogen and other "volatiles" cannot freely range on the lunar surface, and since the Apollo Era the Moon has been considered among "the driest places in the Solar System."

The Moon's "exosphere," however, has since been interpreted as very dynamic, rather than static. The constant rain of cometary water ice and charged particles are thought to literally shatter and bounce all over the Moon, some of it coming to rest in the dusty "Cold Traps," permanently shadowed from disbursing by proton-packed Solar Wind.

Over a four and a half billion year history, the Moon's manifest history of impacts large and small is thought to have gathered many tons of volatiles in these Cold Traps.

NASA's Long-term plans call for a semi-permanent manned presense on the rim of Shackleton Crater, overlooking the 20 mile wide, permanently darkened interior, where some portion may have naturally stored the stuff that both life and rocket fuel are made of.

Spudis, as both a scientist and director, has been closely associated with Lunar and Martian science for thirty years. An penultimate "multi-tasker," Spudis has probably forgotten more about the Moon than most NASA directors will ever know.