Laser message reaches earth from 16 million kilometers away

An innovative experiment as part of NASA's Psyche mission recently achieved a significant milestone, successfully demonstrating laser communication over the farthest distance ever recorded. 

This breakthrough could revolutionize deep space exploration and lead to groundbreaking discoveries about the universe's origins. Launched in mid-October, the Psyche probe is currently en route to investigate an asteroid primarily composed of metals, located between Mars and Jupiter's orbits. 

Over the next six years, the probe will cover a distance of approximately 3.6 billion kilometers to reach the outer region of the main asteroid belt. Alongside its main mission, the Deep Space Optical Communications Technology Demonstration (DSOC) is carrying out its own mission during the initial two years of the journey. 

The DSOC aims to perform the United States' farthest experiment in high-bandwidth laser communications, testing the transmission and reception of data using an infrared laser that is nearly invisible to the naked eye.

Compared to traditional radio wave systems used in previous NASA missions, the laser can transmit data at speeds 10 to 100 times faster. If the experiment proves successful within the next few years, it could serve as the foundation for future communication technology used in human exploration of Mars. 

The DSOC recently achieved a significant feat, known as "first light," by successfully transmitting and receiving its first data from a data-encoded laser beam. The test data was sent from a distance of nearly 10 million miles and reached the Hale Telescope at the Palomar Observatory in the California Institute of Technology, located in Pasadena, California. The distance between DSOC and Hale was approximately 40 times greater than the distance from the Moon to Earth.

Achieving "first light" is one of many critical milestones anticipated at DSOC in the coming months, paving the way for high-data-rate communications capable of transmitting scientific information, high-definition images, and streaming video in support of humanity's next ambitious endeavor: sending humans to Mars," stated Trudy Cortes, director of technology demonstrations for NASA's Space Technology Mission Directorate. Meera Srinivasan, the operations lead for DSOC at JPL, based in Pasadena, Calif., said in a statement, "The Nov. 14 test was the first to fully integrate ground assets and the flight deck, requiring the DSOC and Psyche operations teams to work in tandem. It has been an immense challenge, and we still have significant work ahead, but for a brief period, we were able to transmit, receive, and decode valuable data." 

This is not the first time laser communication has been tested in space. The initial trial of two-way laser communications occurred in December 2021. Since then, experiments have successfully sent optical communications from low Earth orbit to the Moon. 

The Artemis II spacecraft will employ laser communications to transmit high-definition video of the crew's lunar journey. However, DSOC represents the first instance of laser communications being utilized across deep space, requiring precise aiming over millions of kilometers.

The initial testing of the technical demonstration's capabilities will enable the team to refine the laser's pointing accuracy. "Optical communication is a game-changer for scientists and researchers who continually seek to enhance their space missions and will facilitate human exploration of deep space," stated Dr. Jason Mitchell, director of the Advanced Communications and Navigation Technologies Division of NASA's Space Communications and Navigation Program. "More data means more discoveries." As the Psyche mission progresses, the team anticipates additional challenges. 

The DSOC team will monitor the duration of laser message transmission through space. During the first light test, it took the laser only 50 seconds to travel from Psyche to Earth. At the farthest distance between the spacecraft and Earth, it is estimated to take 20 minutes for the laser to reach its destination. Throughout this time, both the spacecraft and Earth will continue to move and rotate, potentially creating reception difficulties. 

Meanwhile, the Psyche spacecraft will continue its preparations for the primary mission, including testing science instruments and activating propulsion systems. These steps are crucial for studying the asteroid upon its arrival in July 2029. The mission aims to determine whether the asteroid represents an exposed core from the early solar system's planetary building blocks.