Spectrometer orbits the moon

NASA LCROSS mission takes a Ocean Optics spectrometer named Alice to the moon to analyze lunar makeup and look for water. The Centaur rocket carrying LCROSS will remain in orbit with the satellite until October 9. At that point the units will separate, sending the rocket, at more than twice the speed of a bullet ...

By Peter Welander July 14, 2009

UPDATE: Oct. 9 from EDN : NASA hits its target .

A custom-engineered spectrometer from Ocean Optics is part of the scientific payload on NASA’s Lunar Crater Observation and Sensing Satellite (LCROSS) mission, which was successfully launched June 18 from the Kennedy Space Center in Cape Canaveral, FL.
Dubbed "Alice" by its builders, the device is designed to help study the makeup of lunar craters with the goal of locating water below the moon’s surface. The Centaur rocket carrying LCROSS will remain in orbit with the satellite until October 9. At that point the units will separate, sending the rocket crashing into the moon at more than twice the speed of a bullet. The rocket impact is expected to generate a 2.2 million-pound plume of matter that Alice will analyze looking for signs of water and other compounds.

In partnership with Aurora Design & Technology , whose work included development of the reflectance viewing optics for the mission, Ocean Optics adapted its highly-sensitive QE65000 spectrometer to survive the harsh conditions of this mission, including extreme temperature ranges, radiation, shock, and vibration.

Alice will measure the reflectivity of the debris cloud as it rises into the sunlight, enabling scientists to distinguish between water vapor, frozen water, and hydrated minerals, such as salts or clays, with molecularly bound water. With a wavelength range of 270-650 nm and an optical resolution of less than 1.0 nm, Alice will be able to identify ionized water (visible at 619 nm), OH radicals (visible at 308 nm), and other organic molecules containing carbon. Though the measurements are to be taken from the dark region of the moon where light is scarce, the unit’s back-thinned detector makes the most of the light available.

Water hidden deep in the moon’s craters could mean drinking water or even the ability to break down the hydrogen and oxygen molecules into rocket fuel, laying the foundation for the moon as a staging point for further space exploration. You can track the progress of Alice and LCROSS on the mission’s website .

-Edited by Peter Welander, process industries editor, PWelander@cfemedia.com,
Control Engineering Process Instrumentation & Sensors Monthly
Register here to select your choice of free eNewsletters .