Citation
Abstract
The Goldstone Solar System Radar (GSSR) group at JPL produced a digital elevation model (DEM) of the lunar south pole using data obtained in 2006. This new DEM has 40-m horizontal resolution and about 5-m relative vertical accuracy. This article explains how this DEM was used to evaluate average solar illumination and Earth visibility near the lunar south pole. The elevation data were converted into local terrain horizon masks for the area within 100 km of the lunar south pole. These topocentric horizon masks were converted into selenographic latitude and longitude coordinates, then compared to regions bounding the maximum Sun and Earth motions relative to the Moon. Estimates of Earth visibility were computed by integrating the area of the region bounding the Earth’s motion that was below the horizon mask. Solar illumination and other metrics were computed similarly. Proposed lunar south pole base sites are examined in detail, with the best site showing multiyear averages of solar power availability of 92 percent and direct-to-Earth (DTE) communication availability of 51 percent. Results are compared with a theoretical model and with actual Sun and Earth visibility averaged over the years 2009 to 2028. Peaks near the lunar south pole with continuous DTE communications are also presented. Results for the lunar north pole were computed using the GSSR DEM of the lunar north pole produced in 1997. The article also explores using a heliostat to reduce the photovoltaic power system mass and complexity.
Keywords
Details
- Volume
- 42-176
- Published
- February 15, 2009
- Pages
- 1–43
- File Size
- 13.3 MB