September 26, 2007, Dunedin, FL--Ocean Optics has custom-engineered a spectrometer for an upcoming NASA mission to the moon's south pole. The Lunar CRater Observation and Sensing Satellite (LCROSS) will carry the Ocean Optics equipment, dubbed "ALICE," to help analyze the makeup of the lunar craters, with the goal of locating water below the moon's surface.
Ocean Optics worked closely with Aurora Design & Technology (Clearwater, FL), the company developing the reflectance viewing optics for the mission, to custom-build a spectrometer to meet NASA's exacting specifications. Ocean Optics said its technology is able to achieve up to 90% quantum efficiency with high signal-to-noise and rapid signal processing speed.
The LCROSS mission will send a rocket crashing into the moon at more than twice the speed of a bullet, in order to study the resulting ejecta cloud. The impact is expected to generate a 2.2 million-pound plume of matter, which another spacecraft carrying ALICE will fly through, looking for signs of water and other compounds. ALICE will measure the reflectivity of the plume as it rises into the sunlight, enabling scientists to distinguish between water vapor, water ice, 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 is designed to identify ionized water (visible at 619 nm), OH radicals (visible at 308 nm), and other organic molecules containing carbon, with a high degree of accuracy. According to the companies, the unit's back-thinned detector makes the most of the available light, a critical feature as the measurements will be taken from the dark region of the moon where light is scarce.
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.
To survive the harsh conditions of the lunar mission, ALICE was designed to withstand extreme temperature ranges as well as significant shock and vibration. All of the materials, optics and mounting hardware were selected with these hazards in mind. Additionally, several electronics modifications were made to accommodate conversion of the communication ports from USB to RS-422 and of the power supply from 5V to 24V.
With only 12 weeks to first prototype, Ocean Optics says ALICE has passed pre-flight testing. It has cycled from -50° to +70° C with very little change in spectral performance and passed flight qualification testing at 15g RMS vibration and over 200g shock.
LCROSS is slated to launch in October, 2008 from the Kennedy Space Center, Florida. The spacecraft will orbit the Earth twice prior to striking the lunar south pole in January 2009.