Mars Laser Communication Demonstration

The Mars Laser Communication Demonstration was a project to demonstrate optical communications on the 2009 Mars Telecommunications Orbiter. "Lasercom sends information using beams of light and optical elements, such as telescopes and optical amplifiers, rather than RF signals, amplifiers, and antennas" [1]

It was a collaboration of Goddard SFC, JPL, and MIT Lincoln Lab. Building on work done by MIT/LL for NASA in 2002/2003.[1]

The program for the Mars Telecommunications Orbiter was cancelled in 2005 and hence also the MLCD project.[2]

Objectives and progress

The goal was a system to transmit data at 1 to 100 M bits/sec (bps) depending on distance and atmospheric conditions.[1] It was planned to use high bandwidth encoding (eg. a Turbo-Code using iterative decoding) and a photon counting receiver (eg. Geiger mode avalanche photo-diodes) to increase the communications efficiency.

By 2004 the project was still evaluating alternative designs, particularly for the Earth terminal.[1]

Flight terminal - on the spacecraft

The optical receiver on the spacecraft would be a 30.5 cm aperture telescope. To steer the telescope to track the beam it would include a Magnetohydrodynamic Inertial Reference Unit (MIRU) being developed for other projects. The transmitter would use a laser, with a fibre amplifier, with about 5 W optical output.[1] Using off the shelf 1.5 um communications devices.

Earth terminal

The earth terminal (for the demonstration) could either use existing astronomical telescopes (eg. Hale telescope), or an Earth terminal based on the Lincoln Distributed Optical Receiver Architecture (LDORA). The earth terminal might transmit at 1030 nm to 1064 nm, at 120 W output. Either multiple beams through a single wide aperture telescope (also used for reception) or 6 separate 30 cm beams in an array of telescopes.[1]

See also
  • Laser space communication

References
  1. Townes, Stephen A.; et al. (2004). "The Mars Laser Communication Demonstration".
  2. BRIAN BERGER (July 2005). "NASA Mars Telecom Orbiter Axed As Space Agency Priorities Shift". Archived from the original on April 11, 2008. Retrieved April 28, 2008.


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