Laser communication systems
Lasers could one day carry interplanetary communication signals between Earth and Mars.
Current Mars rovers and satellites send and receive signals from Earth via radio waves at a data rate of a few megabits per second[1]. If lasers could be used instead, the transmission would form a tighter beam, with more of the total energy being delivered to the receiving antenna and less wasted. This means a higher data rate, for the same power consumption[2]. With current technology, at Earth-Mars range, a laser could increase bandwidth by a factor of 10 compared to radio waves, making high-definition video streams possible. Future refinements in the technology could lead to a data rate 100 times that of radio waves[1].
Laser communication has never been tried at this distance. NASA plans to test long-distance communication using an infrared laser in conjunction with an upcoming mission that will send a probe to an asteroid, scheduled to launch in 2022 and arrive at its destination in 2026.
A new Deep Space Network antenna currently under construction will have dual functionality for both radio and laser signals[1].
Engineering challenges for Earth-Mars laser communication include interference from sunlight, precise pointing of the narrow beam despite spacecraft motion and vibrations[2], interference from Earth's atmosphere, space temperature extremes, radiation, and forces on delicate equipment during launch[1].
Alternatively, if enough power is available then radio communications may continue to be used for high bandwidth communications.
References
- ↑ 1.0 1.1 1.2 1.3 Carter, J., 2020, NASA Will Soon Use 'Space Lasers' To Give Us Live Video From Mars And The Moon, Forbes, https://www.forbes.com/sites/jamiecartereurope/2020/02/11/how-space-lasers-will-bring-the-solar-system-its-broadband-moment-and-live-video-from-mars.
- ↑ 2.0 2.1 Seffers, G.I., 2018, NASA Counts Down to Laser Communications for Mars, SIGNAL Magazine, https://www.afcea.org/content/nasa-counts-down-laser-communications-mars.
