Laser communication

Laser communications from space have been researched heavily in recent years, with groups focusing on Earth orbit demonstrators, and satellite to satellite links. The Lunar Reconnaissance Orbiter has also shown the possibility to transmit data from another planetary body to Earth using a laser as the source. With laser technology improving and the increase in Earth based optical ground stations, laser communication could be a reasonable technology to be a major data link between the Earth and Mars. The new Starlink network being set up by SpaceX uses laser links between satellites to provide the required bandwidth. In 2024 SpaceX proposed Marslink, a Starlink network for Mars, in response to a NASA request for proposal. A basic Starlink satellite can handle 20 Gbps (giga bits per second). However, ground stations and positioning signals are required, so the actual performance will depend on these. Coverage is also an issue, with a large number of satellites required to provide complete coverage.