: LOLA

Principal Investigators for LOLA :

David Smith Solar System Exploration Division, Goddard Space Flight Center, Greenbelt MD 20771 301 614-6010

Maria Zuber Dept. of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Boston MA 02139 617 253-6397

The Lunar Orbiter Laser Altimeter (LOLA) investigation will provide a precise global lunar topographic model and geodetic grid that will serve as the foundation of this essential understanding. Building on our previous experiences on the Moon and Mars, we now know that topography at scales from local to global is necessary for landing safely and, in addition; it preserves the record of the evolution of the surface which contributes to decisions as to where to explore. The topographic model provided by LOLA will be at a level that will allow safe landings and enhance exploration - driven mobility once on the lunar surface.

The LOLA investigation has two overarching objectives that will significantly advance the Nation's Space Exploration Initiative:

+ Produce a high-resolution global topographic model and global geodetic framework that enables precise targeting, safe landing, and surface mobility to carry out exploratory activities.

+ Characterize the polar illumination environment, and image permanently shadowed polar regions of the Moon to identify possible locations of surface ice crystals in shadowed polar craters.

The LOLA instrument pulses a single laser through a Diffractive Optical Element (DOE) to produce five beams that illuminate the lunar surface. For each beam, LOLA measures time of flight (range), pulse spreading (surface roughness), and transmit/return energy (surface reflectance). With its two-dimensional spot pattern, LOLA unambiguously determines slopes along and across the orbit track.

Image above : LOLA instrument Artist Rendering.