The message was transmitted by the infrared laser beam of NASA’s Psyche probe, the spacecraft traveling towards the asteroid of the same name, located in the outer part of the main asteroid belt, between the orbits of Mars and Jupiter. The communication traveled 226 million kilometers in space, one and a half times the distance between Earth and the Sun.
Credit: Malone
A laser message, transmitted to Earth from the incredible distance of 226 million kilometers – one and a half times what separates us from the Sun – has just marked a new record in the pioneering era of optical communications from deep space. It was sent by the Psyche probe, the NASA spacecraft launched last October and currently traveling towards the asteroid of the same name, located in the outer part of the main asteroid beltbetween the orbits of Mars and Jupiter.
After the first tests from “a few” tens of millions of kilometers away (about 80 times that between the Earth and the Moon), the innovative laser communication technology on board Psyche, called Deep Space Optical Communications (DSOC), was tested now that the probe is about seven times further away, successfully sending a message from the greatest distance ever experienced for this type of communications and, NASA underlines in a note, transmitting data at a maximum speed of 25 MbpsThat “far exceeds the 1 Mbps target expected from that distance”.
The laser message transmitted to Earth from Psyche shatters a new record
The new laser message transmitted to Earth from Psyche consisted of a copy of the technical data which the probe normally sends via radio waves to NASA’s Deep Space Network (DSN). The technical data was then transmitted for the first time also via the infrared laser beam (Deep Space Optical Communications, DSOC), when the spacecraft was at 226 million kilometers from Earth (in previous tests, the data transmitted was not that collected by Psyche, but preloaded digital videos and photographs – such as the video of Taters the cat –, or data sent to Psyche and then retransmitted to Earth).
The Earth has just been hit by an energy beam transmitted from space
The location of the Psyche probe on April 8, when the spacecraft’s laser beam transmitted data at a rate of 25 Mbps over a distance of 226 million kilometers from Earth / Credit: NASA/JPL-Caltech
The new test, which took place on April 8, also demonstrated that, even from 226 million kilometers away, data could be downloaded at a maximum speed of 25 Mbps: a result which, as mentioned, goes well beyond the expected target of at least 1 Mbit per second and is “10 to 100 times faster than state-of-the-art radio frequency systems currently used by deep space missions” NASA specified.
“We downlinked about 10 minutes of duplicate spacecraft data during a pass on April 8 – said Meera Srinivasan, project operations manager at NASA’s Jet Propulsion Laboratory (JPL) – . Until then, we had been sending tests and diagnostic data in 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”.
Waiting for the next test in June
Optical communication technology from deep space is proving to be very promising, although there are still some aspects to be resolved, such as interruptions due in the presence of cloudsa problem that radio communications do not suffer from.
“We have learned a lot about how far we can push the new system when the skies are clear even if, occasionally, storms disrupted operations both at Table Mountain and at Palomar (the two ground stations that receive optical communications from Psyche, ed.) – explained Ryan Rogalin, project electronics manager at JPL –. While radio frequency communications can work in most weather conditions, optical communications require relatively clear skies to transmit data at high bandwidth”.
The wait is all for now the next test which will take place in Junewhen Psyche is at a distance of 2.5 times that between Earth and Sun: the maximum distance between Mars and Earth will also be equal and, if the results are as hoped for, it will mean that in the future it will be possible to develop an optical communication network to support humanity’s next giant step: the sending of beings humans on Mars.
