Exploration and Communications Coverage Trade Studies for the International Lunar Relay Satellite
- Paper number
IAC-09.A3.2INT.6
- Author
Dr. Charles Lee, California State University, United States
- Coauthor
Ms. Lynette Zamora, United States
- Year
2009
- Abstract
Efforts by the U.S. and other international space agencies (Canada, France, Germany, India, Italy, Japan, the Republic of Korea, and the United Kingdom) are underway to develop and deliver instruments to the lunar surface to explore the Moon collaboratively in the next decade. A series of geophysical nodes, begin with two NASA landers to be launched as early as 2013 and 2014, will evolve gradually into an International Lunar Network (ILN) of six to eight elements. These geophysical monitoring stations are expected to be launched and operated by the different space organizations, but will function simultaneously as a single network. The ILN is likely situated at one of the ten high-priority landing sites, which have been identified in the NASA’s Exploration Systems Architecture Study (ESAS) as locations of profound scientific value. Six among these sites are either located on the far side of the Moon, which has no direct contact with Earth, or at the lunar limb, where it could, depending on the libration of the Moon, spend days without seeing Earth. Thus the presence of a relay satellite at the Moon will make the establishment of the ILN flexible, versatile, and global. More importantly, communication payload of the geophysical nodes, in both mass and power, will be reduced as lesser effort is required to send data to Earth via a relay satellite at the Moon. The International Lunar Relay (ILR) satellite is named because it requires the use of compatible communications spectrum, standards, compliances, and interoperability between the different international partners. In this article, we focus on the coverage and the telecom capabilities provided by the different orbit selections for the ILR. We particularly consider stable frozen lunar orbits that can provide pole-to-pole global communication coverage and at the same time excellent data throughput. Nominal S-band telecom configurations for both the geophysical stations and the ILR will be assumed. Various contact and telecom metrics such the contact frequency, duration, maximum gaps, link performance, data rates, and data throughputs will be calculated using the JPL-developed Telecom Orbit Analysis and Simulation Tool (TOAST). We will end the article with the discussion of our findings and the optimal orbit suggestions for the ILR.
- Abstract document
- Manuscript document
(absent)