We recently wrote about how the story of the NASA Voyager 1 space probe took a positive turn with the restoration of part of the communication (for the moment only the engineering data). Communicating in space is complex and when distances are very large things become even more complicated. In view of future human missions to Mars in the coming decades the NASA and other space agencies are experimenting with new systems. One of these is on board the NASA Psyche space probe directed towardsmetallic asteroid 16 Psyche (which it will reach in 2029).
The optical system, based on near infrared lasershould make it possible to significantly increase thebandwidth available for broadcasts than those based on radio waves (conventionally used). This means being able to send more data to Earth. In December last year a “friendly” test had seen the probe transmit a video of a cat playing with a laser pointer and now comes another proof of the Deep Space Optical Communications or DSOC.
NASA Psyche: new laser transmission from over 200 million kilometers
According to what was reported by JPL and by the space agency la NASA Psyche space probe she managed to employ the optical communication system (which however is not the main one and is still in the experimental phase) from a distance of 226 million kilometersmuch higher than those achieved previously.
Meera Srinivasan (of JPL) stated that “We downlinked approximately 10 minutes of duplicate spacecraft data during a flyby on April 8. Until then, we had been sending test and diagnostic data into our downlinks from Psyche. This represents a significant milestone for the project as it shows how optical communications can interface with a spacecraft’s radio frequency communications system”.
Compared to the test in December 2023, the transmission speed decreased considerably (the maximum speed was 267 Mbps). In the test Of April 2024 in fact, a maximum of i have been reached 25Mbps, with a minimum target of 1 Mbps, but the distance was also seven times greater. Interesting to note that NASA Psycheduring the test, was transmitting both in radio frequency to the Deep Space Network both via laser at Caltech’s Palomar observatory in California.
The amount of data sent and received during the test was small and included photographs of pets as well as engineering data. The data overall traveled approximately 450 million kilometers (round trip). One of the problems to be solved is the variability of weather conditions on Earth which could interrupt optical transmissions when particularly thick clouds are present. The better performance of the optical system via laser instead they are obtained with completely clear skies.
As written above, the Deep Space Optical Communications system Of NASA Psyche it’s not the main one yet. Further tests will be necessary (including by other probes and satellites) before definitively validating space transmission with optical systems and then disposing of those that use radio waves. Over the years, however, we will see more and more tests of this type both in low Earth orbit and at increasing distances, a turning point for sending and receiving data from space.
