Lunar Atmosphere and Dust Environment Explorer (LADEE)

Description

The Lunar Atmosphere and Dust Environment Explorer (LADEE) is currently under study for launch in 2011 on a Minotaur-V. LADEE is designed to characterize the tenuous lunar atmosphere and dust environment from orbit. The scientific objectives of the mission are: 1) Determine the global density, composition, and time variability of the fragile lunar atmosphere before it is perturbed by further human activity; and 2) Determine the size, charge, and spatial distribution of electrostatically transported dust grains and assess their likely effects on lunar exploration and lunar-based astronomy. further objectives are to determine if the Apollo astronaut sightings of diffuse emission at 10s of km above the surface were Na glow or dust and document the dust impactor environment (size-frequency) to help guide design engineering for the outpost and also future robotic missions.

The nominal science orbit will last 100 days. The orbiter will carry a neutral mass spectrometer, an ultraviolet/visible spectrometer, and a dust detector. The total science payload mass must be less than 20 kg with normal power of 60 W and a 100 W maximum. There is also a technology demonstration, the Lunar laser Communication Demonstration. Communications will be via S-band with a 10 Kbps science data rate. Total mass of the orbiter will be approximately 130 kg.

The instruments will detect and constrain the abundances of species expected to be prevalent at the 50 km altitude, due to the solar wind and its interactions with the surface, release from regolith, and radiogenic sources. The NMS is a quadrupole mass spectrometer designed ot detect species up to 150 amu and will look for CH4, S, O, Si, Kr, Xe, Fe, Al, Ti, Mg, OH, and H2O. The UV/Vis will detect Al, Ca, Fe, K, Li, Na, Si, T, Ba, Mg, H2O, and O and will monitor the dust composition.

Slated for launch in April 2008 on a Minotaur with a Star 37FM or FMV upper stage, LADEE will spend about 5 months reaching nominal lunar orbit and checking out systems before its 100 day science mission starts. The nominal science orbit will be a near-circular (about 50 km) retrograde equatorial orbit with a period of 113 minutes. The periselene will be over the sunrise terminator. After the science mission is complete the orbiter will be put into a higher elliptical orbit for the technology demonstration, which will last for about 9 months. Total mission cost is estimated at roughly $100 million.