Communication Link Design

Overview

For all exploratory space missions, the communication system forms the heart of the whole design. The Apollo 11 mission captured the world’s imagination primarily because of the live video streams that were transmitted to the earth from the moon. For the Lunar X-prize, the challenge is to transmit real time High Definition video signals from the rover to the earth. This requires high data rate error free signals. One important difference between the design of the uplink and the downlink is the data rate. While the uplink is a control channel having 1 kbps of data rate and Bandwidth equal to 775 Hz, the downlink is a HD video channel having 10 Mbps real data rate and 7.75 MHz of Bandwidth. Because of the high bandwidth, forward error correction methods are required only on the downlink.

Because the Allen Telescope Array in Hat Creek, CA has offered free services for seven earth days to receive & demodulate the Mooncast for the Lunar X-prize, ATA would be used as our Earth Station.

The following table summarizes total cost of the communication system. The break down of these cost can be found HERE.

Summary of Communication Cost ($)

Rover to Landing Station

21,550.00

Landing Station Transponder

34,434.40

Rover to Earth Link

15,800.00

Earth to Rover Link

8,256.00

Total

80,040.40