NASA is working on a new method of communicating with spacecraft from Earth that uses lasers to transmit data — and they’re not just doing it because it sounds awesome, which it does.
If successful, this new technique, called free-space optical communication (FSOC), could greatly improve the speed of space communication and enhance the abilities of spacecraft.
NASA is preparing to launch the Laser Communications Relay Demonstration (LCRD) in 2019. For the demonstration, the agency plans to send laser signals from California to a satellite in geostationary orbit 25,000 miles away and back to a different ground station.
In 2023, the Deep Space Optical Communications project is planning to fly to a metallic asteroid and beam laser signals back to Earth at a distance even farther than the LCRD’s in a more challenging test of the technology.
NASA has been working on laser communications for a while. The 2013 Lunar Laser Communication Demonstration (LLCD) successfully sent data to Earth from a lunar orbiter at a rate six times that of modern radio frequency communications.
Current space communications use radio frequency (RF) to transmit information. The radio spectrum is one part of the electromagnetic spectrum and covers the frequencies of 1 Hz to 3 THz.
Only two facets of the electromagnetic spectrum can make it through the Earth’s atmosphere. One is visible light and the other is radio — although only parts of the radio frequency range can break through. Radio frequencies between about 30 MHz and 30 GHz can be used for space communication.
Space communication is just one of the many things radio waves are used for. People use radio waves for all kinds of purposes including communications, powering robotics, and sealing medical IV bags. There are even certain places on Earth designated as radio quiet zones so scientific study can take place. This leads to intense competition for the right to use certain frequencies.
Advantages of FSOC
With all of its many applications, the radio spectrum has become crowded with users and high amounts of data volume. One of the advantages of laser-based communications is avoiding this congestion.
NASA demonstrated that FSOC could be used to quickly send large amounts of data without error. In fact, using laser technologies could lead to an expansion of data-carrying capacity to anywhere from 10 to 100 times what’s possible with radio frequency communication. This will allow scientists to collect more extensive data and maybe one day even view video broadcasted from outer space.
The increase in the speed of transmissions FSOC technology will bring will also allow researchers to monitor occurrences closer to when they happen and communicate with spacecraft more easily.
Additionally, FSOC transmission equipment will have construction and operation advantages over RF because it can be smaller and requires less power.
Challenges to FSOC
Although tests of FSOC have so far been overwhelmingly successful, the technology does have some potential weaknesses. For example, optical communication is at risk for interference from cloud cover and atmospheric turbulence.
To combat this difficulty, ground stations would have to be located in areas with fairly consistent clear skies. Radio frequency technologies would be used as a backup to ensure communication wouldn’t be cut off because of the weather. Equipment may also include adaptive optics that can be adjusted based on weather conditions.
Laser beams are also much narrower than radio waves, so they’re more difficult to track, direct and receive. Although this is a challenge, demonstrations have successfully aimed and received optical transmissions.
Impact on Space Exploration
The ability to send more data more quickly between outer space and Earth is an important advancement for space exploration.
Scientists will be able to communicate with spacecraft faster and more reliably, increasing the feasibility of interplanetary missions that venture deeper into space.
The surge in the amount of data scientists can send and receive will also allow them to get a better picture of the areas of space they explore. They might even be able to monitor events in real time — or at least closer to it — with this technology.
The ability to transmit video could also be extremely beneficial. Every astronaut could potentially have a live video feed they send back to Earth, allowing technicians to track their progress and keep them safer. Broadcasting video from outer space also creates a fascinating, new way for researchers to study the cosmos and for everyday people to share in the experience.
FSOC technology doesn’t just have implications for space travel either. The military and other groups may also benefit from a faster communication method with a larger data capacity and a less-crowded spectrum.
Improving space communication is crucial for providing the advancements scientists need to explore deeper into outer space and to help us better understand the universe we live in. FSOC has the potential to do just that.
Megan Ray Nichols is a freelance science writer. Most notably, she contributes regularly to American Machinist and Manufacturing Transformation. She also writes weekly on her personal blog, Schooled By Science. There, Megan enjoys discussing scientific news and discoveries. Subscribe today and follow Megan on Twitter to stay connected.
Filed Under: Aerospace + defense