2017.A.2.3. Communication Relay and Navigation Micro Satellite for Lunar South Pole Landing Exploration Mission

Author(s)

Lihua Zhang (1)
Peng Wang (1)

DFH Satellite Co. Ltd, China

Session

A.2

Keywords

Communication relay Navigation Lunar

Abstract

After lunar nearside and farside landing exploration mission, the south pole of the Moon will be the next objective for robotic exploration mission. Since the lunar poles and lunar farside have minimal to no direct access to Earth, it is impossible to effectively communicate and navigate with surface landers and rovers in these areas of the Moon without a dedicated spacecraft.

In order to support future lunar south pole exploration missions, a communications and navigation micro-satellite system concept is described. Based on ever maturing micro and nano satellite technology, this relay and navigation satellite design can be implemented at low cost and short development time. The total mass of the spacecraft is only about 50kg. The design concept is a 3-axis stabilized spacecraft that can support forward and return links with lunar surface assets, as well as navigation and location to them. X band will be used for both communication relay links and the links between spacecraft and Earth. A high gain parabolic antenna is used for communication relay links with lunar surface elements and the large volume of science data down link to Earth. Four-way ranging technique will be used to provide high precision location and navigation information for lunar surface assets. The payload will be developed based on heritage designs from CE-4 relay satellite.

An inclined elliptical frozen orbit will be used for the spacecraft. it enables a communication link to be established from the spacecraft to any surface element in the southern hemisphere for over 8.5 hours, If longer coverage is needed, a constellation with three spacecraft can be developed. The three spacecraft can provide 100% continuous, two-fold lunar south pole coverage. The spacecraft would be launched together with the lander and the rovers. It would begin a trans-lunar injection after separation from the launch vehicle. A series of course correction burns would be performed to ensure spacecraft reach the Moon’s gravitational field. Then through several capture burns to enter a highly elliptical frozen mission orbit with an 12 hours period. the total delta-V requirement is approximately 500 m/s. It will be provided by green ADN propulsion system. The spacecraft would operate in this orbit for a nominal 3 years mission. Because of little orbit station-keeping, it is possible to extend lifetime of spacecraft.