ESA to Beam World’s Longest Laser Light to Carry Science Discoveries From Space to Earth

The European Space Agency (ESA) will use laser beams to deliver scientific discoveries from space to Earth.

The concept of optical communications -- using laser to signal across space -- has a long heritage, but it is only now that it will be operational with the European Data Relay System's (EDRS) "Space Highway" returning ample data from the Earth-observing Sentinel satellites.

According to Clemens Heese, an optoelectronic engineer at ESA's Opto-Electronics Section, they also hope to use this technology for the proposed Asteroid Impact Mission (AIM), operating from up to 75 million km away, or half the distance between Earth and the Sun.

The mission, slated to launch in October 2020, involves traveling to a binary star system - the paired Didymos asteroids, which will come 16-million-km closer to Earth by 2022. The spacecraft is tasked to perform high-resolution visual, thermal and radar mapping of the system's moon -- which is called Didymoon -- to build detailed maps of its surface and interior structure.

Through AIM, ESA wants to demonstrate the capability of optical communications. The plan is for AIM to carry its own optical communications terminal to return scientific results from the Didymos binary asteroids by shining a laser back to Earth across a maximum of 75 million km of empty space.

"That might sound a lot, but operating around Mars one day will involve further distances still," Heese said in a statement.

According to ESA, optical communications is capable of returning results at several times higher data rates than standard radio signals. A laser beam shone back from AIM's laser telescope would have a ground footprint of about 1,100km. However, the equivalent radio beam radiating out across space would end up wider than the Earth itself.

"Today literally every bit of the internet is transmitted with lasers through fiber links. That means we have a big terrestrial source of laser components and building blocks, which we can tailor and develop further for use in space," Heese said. "We'll end up with different virtual instruments -- like a Swiss Army knife approach."