Earth Receives Laser Message From Deep Space, 140 Million Miles Away

The asteroid Psyche is located in the asteroid belt between the planets Mars and Jupiter. Psyche’s robotic explorer had the additional mission of testing laser communications.

Equipped with the Deep Space Optical Communications (DSOC) system, Psyche aims to make laser communication possible across vast distances in space, promising much faster connections than current methods. Despite primarily using radio frequency communication, the optical communications technology has proven its capability.

In a remarkable feat, the laser communications demo successfully transmitted engineering data from over 140 million miles away, 1.5 times the distance between Earth and the sun, after interfacing with Psyche’s radio frequency transmitter. The DSOC also successfully interfaced with Psyche’s radio transmitter, allowing it to transmit information and engineering data directly from the spacecraft back to Earth.

Meera Srinivasan, the project’s operations lead at NASA’s Jet Propulsion Laboratory (JPL) in Southern California, explained that during a pass on April 8, about 10 minutes of duplicated spacecraft data was downlinked. This duplicated data was transmitted via laser communications, while the original Psyche data was sent to ground control using standard radio-frequency communications channels on NASA’s Deep Space Network (DSN).

The objective was to assess if laser communications could perform as effectively, if not better, than traditional methods. NASA’s optical communications demonstration has proven it can transmit test data at a maximum rate of 267 Mbps using the flight laser transceiver’s near-infrared downlink laser, which is similar to broadband internet speeds.

However, because the spacecraft is now much farther away, the data transmission rate is lower. During a test on April 8, the spacecraft successfully transmitted test data at a maximum rate of 25 Mbps, exceeding the project’s goal of proving at least 1 Mbps was achievable at that distance.

Psyche is reportedly stable and healthy as it makes its way towards the Psyche 16 asteroid between Mars and Jupiter.