The milestone, reached on July 29, 2024, concluded the first phase of the mission since its launch aboard the Psyche spacecraft on October 13, 2023. Meera Srinivasan, the operations lead for the project at NASA's Jet Propulsion Laboratory (JPL), highlighted the importance of this achievement, stating, "The milestone is significant. Laser communication requires a very high level of precision, and before we launched with Psyche, we didn't know how much performance degradation we would see at our farthest distances. Now the techniques we use to track and point have been verified, confirming that optical communications can be a robust and transformative way to explore the solar system."

Managed by JPL, the DSOC experiment uses a flight laser transceiver aboard the Psyche spacecraft and two ground stations. The downlink station is the 200-inch Hale Telescope at Palomar Observatory in California, while the uplink station is the Optical Communications Telescope Laboratory at JPL's Table Mountain facility, which transmits 7 kilowatts of laser power to the spacecraft.

Laser communications offer significant benefits over traditional radio frequency systems by allowing the transmission of data at rates up to 100 times faster. This technology is critical for future missions, including crewed missions to Mars, which will require the ability to send complex scientific data, high-definition imagery, and video.

Currently, Psyche continues its journey toward a metal-rich asteroid in the asteroid belt between Mars and Jupiter, propelled by ion thrusters and remaining in stable condition.

Performance Highlights
The DSOC technology demonstration transmits data via near-infrared light, which allows for much higher data transfer rates than radio waves. Even when Psyche was 33 million miles (53 million kilometers) away, the system transmitted data at 267 megabits per second, comparable to broadband internet speeds on Earth.

On June 24, when Psyche was 240 million miles (390 million kilometers) from Earth, the system achieved a sustained data transfer rate of 6.25 megabits per second, far exceeding what a comparable radio frequency system could achieve at that distance.

Successful Testing
A key goal of the DSOC project is to demonstrate that laser communication can reliably transmit large volumes of data at higher speeds. During this phase, the system successfully sent data, including unique digital sets like high-definition video and images from the Psyche spacecraft. Notably, on December 11, 2023, it transmitted the first ultra-high-definition video from space, which featured a cat named Taters, from 19 million miles away.

Abi Biswas, the technology demonstration's project technologist at JPL, said, "We met that goal and transferred huge quantities of test data to and from the Psyche spacecraft via laser." Almost 11 terabits of data were downlinked in the first phase of the project.

The next phase of the mission is scheduled to begin on November 4, when the flight transceiver will be powered up again to ensure the hardware's continued operation. Ken Andrews, project flight operations lead at JPL, explained, "We'll power on the flight laser transceiver and do a short checkout of its functionality. Once that's achieved, we can look forward to operating the transceiver at its full design capabilities during our post-conjunction phase that starts later in the year."

Related Links
Deep Space Optical Communications (DSOC)
Space Technology News - Applications and Research