Recent and upcoming deployments of satellite laser communication systems are bringing Internet-like speeds for data transmission in space. The result could be a revolution in communication, both on Earth and across the solar system.
Laser communications through optical fibers move tens of terabits of data every second between cities and across oceans. But for the majority of Earth’s surface, where running fiber is impractical physically or financially, communication satellites in space provide connectivity—to remote ground users and also to mobile platforms such as aircraft, ships and even other satellites. These links rely on radio-frequency (RF) communications, which, while reliable, are orders of magnitude slower in moving data than optical fiber links, and have issues related to antenna footprint, power requirements and limited available spectrum.
The potential for the laser to overcome these issues in space was realized soon after its invention, although its special properties introduced new issues, such as the pointing and tracking of narrow beams over great distances while overcoming cloud cover, turbulence and other hurdles introduced by the atmosphere. Although the first laser communication systems were demonstrated in space in the 1990s, it is only recently that the technology, reliability and economics of photonic components have combined with the need for more bandwidth to push these systems more broadly into operation. The U.S. National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) are now deploying their first operational systems, which could pave the way for later commercial suppliers and, in future years, revolutionize communication both across the globe and across the solar system.