Lasers to boost communication across space
The slow download speeds associated with dial-up Internet are a distant memory for many people; however, slow download speeds are still a reality for scientists and engineers operating spacecraft many millions of miles from the Earth. For the last 60 years, the only way to communicate with spacecraft has been via radio. That could be changing soon as NASA prepares to test out new technologies using lasers for communications that, if successful, would greatly expand the capabilities of spacecraft both near and far.
So-called optical communication, which would carry information over laser light, could yield an increase in data-carrying capacity as much as 10 to 100 times what is possible via radio communication. These higher data rates would allow for scientists to collect data faster and to study sudden events – such as dust storms, cryovolcanoes, or spacecraft landings – and even enable the broadcast of video from the surface of other planets.
“Laser technology is ideal for boosting downlink communications from deep space,” said Abi Biswas, the supervisor of the Optical Communications Systems group at NASA’s Jet Propulsion Laboratory, Pasadena, California. “It will eventually allow for applications like giving each astronaut his or her own video feed, or sending back higher-resolution, data-rich images faster.”
Radio waves and lasers travel at the speed of light, but lasers travel in a higher-frequency bandwidth that enables them to carry more information. Having a means of sending more information across space in less time is an important advancement in lockstep with the increasing complexity of interplanetary missions.
NASA’s Mars Reconnaissance Orbiter (MRO), which by itself is set to eclipse the total amount of data returned by all other interplanetary missions combined later this year, transmits data at speeds up to 6 Mbps. Biswas estimates that MRO could transmit data up to 250 Mbps if it was equipped with a laser communications system.
That data rate might still seem slow, but it would represent a huge leap forward in deep space communications. NASA has planned two upcoming missions to test the technology in space for the first time.
In 2019, the Laser Communications Relay Demonstration (LCRD) will be launched to a geostationary orbit 25,000 miles (40,000 kilometers) from Earth and relay laser communications between two different ground stations in California. Among other things, it will seek to understand how atmospheric phenomenon, such as clouds and dust, can interfere with space-based laser communications.
The Deep Space Optical Communications (DSOC) experiment is scheduled to launch in 2023 as a part of the upcoming NASA Discovery mission to the asteroid Psyche. While also testing laser communications at a greater distance than with LCRD, it will have the added challenge of accounting for the Earth’s rotation as it sends information embedded in its laser beams across the Solar System. For all the challenges ahead, successfully demonstrating deep space laser communications would be a game changer for how researchers communicate with spacecraft in the decades ahead.
Video Courtesy of NASA.gov Video
Paul is currently a graduate student in Space and Planetary Sciences at the University of Akransas in Fayetteville. He grew up in the Kansas City area and developed an interest in space at a young age at the start of the twin Mars Exploration Rover missions in 2003. He began his studies in aerospace engineering before switching over to geology at Wichita State University where he earned a Bachelor of Science in 2013. After working as an environmental geologist for a civil engineering firm, he began his graduate studies in 2016 and is actively working towards a PhD that will focus on the surficial processes of Mars. He also participated in a 2-week simluation at The Mars Society's Mars Desert Research Station in 2014 and remains involved in analogue mission studies today. Paul has been interested in science outreach and communication over the years which in the past included maintaining a personal blog on space exploration from high school through his undergraduate career and in recent years he has given talks at schools and other organizations over the topics of geology and space. He is excited to bring his experience as a geologist and scientist to the Spaceflight Insider team writing primarily on space science topics.