NASA has used lasers to communicate with a probe deep in space for the first time. The US space agency exchanged data with the Psyche spacecraft, which is on its way to the asteroid of the same name and is already over 40 times further away from Earth than the moon – almost 16 million kilometers. According to NASA, this is the furthest demonstration of optical communication to date.
Advertisement
So far, space communication has still relied on radio waves. The near-infrared laser communication, which has now been successfully tested, also uses electromagnetic waves for data transmission, but with higher capacity thanks to significantly narrower waves. This allows ground stations to receive more data. NASA assumes 10 to 100 times the volume of data. This, in turn, will help with future human and robotic missions and also allow scientific instruments with higher resolution, for example for image transmission.
Asteroid probe for research and communications testing
NASA’s Psyche space probe launched at the beginning of October to the asteroid of the same name, which orbits the sun between Mars and Jupiter. Also on board is the optical space communications instrument DSOC (Deep Space Optical Communications) for a NASA technology demonstration, as chief scientist Lindy Elkins-Tanton explained in an interview with heise online. “It is supposed to communicate with the Earth using a laser, because this allows much more data to be encoded than with radio waves. We are testing the device on the way to Psyche, at approximately an Earth-Mars distance. We will not use the laser for scientific purposes “Use the work yourself, but the test is used for future communication to Mars with high bandwidths.”
Since this is still a test, mission data is not yet being transmitted via laser. However, the space agency was able to test for possible interference with other elements of the spacecraft that could have resulted from the use of the laser, such as NASA explains.
Challenges of optical space communication
Communicating with an object in space is a particularly optical challenge because both the spacecraft and our planet are in motion. In DSOC’s current test, the near-infrared photons took about 50 seconds to travel from the probe to Earth. Once the probe has arrived at the asteroid, the transmission time is extended to up to 20 minutes. Both uplink and downlink lasers must be adjusted accordingly.
Optical communication methods have been tested in low Earth orbits and even to the Moon, but laser communication with the Psyche probe was the first test in deeper space. NASA describes this as the first step for possible communication routes to stations and spacecraft on the moon or even Mars.
(fds)