NASA receives laser communications from a distance of more than 140 million miles

NASAThe Deep Space Optical Communications Experiment also interacted with the Psyche spacecraft's communications system for the first time, transmitting engineering data back to Earth.

Aboard NASA's Psyche spacecraft, the agency's deep-space optical communications technology demonstration continues to break records. While the asteroid-bound spacecraft does not rely on optical communications to send data, the new technology has proven to be up to the task. After interacting with Psyche's radio-frequency transmitter, the laser communications display transmitted a copy of engineering data from a distance of more than 140 million miles (226 million kilometers), equivalent to one and a half times the distance between Earth and the Sun.

This achievement provides a glimpse into how spacecraft will use optical communications in the future, enabling higher data rate communications of complex scientific information as well as high-definition images and video to support humanity's next giant leap: sending humans into space. Mars.

This visualization shows the position of the Psyche spacecraft on April 8 when the DSOC aeronautical laser transceiver transmitted data at a rate of 25 megabits per second over a range of 140 million miles to a downlink station on Earth. Image source: NASA/JPL-Caltech

“We delivered about 10 minutes of duplicate spacecraft data during its flyby on April 8,” said Meera Srinivasan, project operations lead at NASA's Jet Propulsion Laboratory in Southern California. “Until then, we had been transmitting test and diagnostic data in our downlinks from Psyche. This represents an important milestone for the project by showing how optical communications can interact with the spacecraft's radio frequency communications system.”

The laser communications technology in this demonstration is designed to transmit data from deep space at rates 10 to 100 times faster than modern radio frequency systems used by deep space missions today.

After its launch on October 13, 2023, the spacecraft remains intact and stable during its journey to the main asteroid belt between Mars and Earth. Jupiter To visit the asteroid self.

Exceed expectations

NASA's Optical Communications demonstration showed that it can transmit test data at a maximum rate of 267 megabits per second (Mbps) from the near-infrared downlink laser of the laser transceiver — a bit rate similar to broadband Internet download speeds.

This was achieved on December 11, 2023, when the experiment sent a 15-second high-resolution video to Earth from a distance of 19 million miles (31 million kilometers, or about 80 times the distance between the Earth and the Moon). Video, along with other testing data, including digital versions from Arizona State University Psychologically inspired The artwork was uploaded to an aviation laser transceiver (see image below) ahead of Psyche's launch last year.

The Deep Space Optical Communications (DSOC) laser transceiver is on display at NASA's Jet Propulsion Laboratory in Southern California in April 2021, before being installed inside its boxy housing that was later integrated with NASA's Psyche spacecraft. The transceiver consists of a near-infrared laser transmitter to send high-speed data to Earth, and a sensitive photon counting camera to receive low-speed data sent from Earth. The transceiver is mounted on a set of struts and actuators — shown in this image — that stabilize the optics from the spacecraft's vibrations. Image source: NASA/JPL-Caltech

Now that the spacecraft is more than seven times farther away, the rate at which it can send and receive data has decreased, as expected. During the April 8 test, the spacecraft transmitted test data at a maximum rate of 25 Mbps, far exceeding the project's goal of proving at least 1 Mbps can be achieved at that distance.

The project team also instructed the transceiver to optically transmit the data generated by Psyche. While Psyche was transmitting data via its radio frequency channel to NASA's Deep Space Network (DSN), the optical communications system simultaneously transmitted a portion of the same data to the Hale Telescope at Caltech's Palomar Observatory in San Diego County, California – It is a basic demonstration of downlink earth station technology.

“After receiving data from DSN and Palomar, we visually verified the associated data in Jet Propulsion Laboratorysaid Ken Andrews, project flight operations lead at JPL. “It was a small amount of data transferred over a short period of time, but the fact that we are doing it now has exceeded all of our expectations.”

Fun with lasers

After the launch of Psyche, the optical communications demo was initially used to link pre-loaded data, including data Taters cat video. Since then, the project has proven that the transceiver can receive data from… High power uplink laser At JPL's Table Mountain facility, near Wrightwood, California. Data can also be sent to a transceiver and then linked back to Earth the same night, as the project demonstrated in a recent “transformation experiment.”

This experiment transmitted test data — as well as digital pet photos — to Psyche and back again, a round trip of up to 280 million miles (450 million kilometers). It also communicated large amounts of engineering data for the technology demonstration to study the properties of the optical communications link.

“We've learned a lot about how far we can push the system when we have clear skies Storms “They have halted operations at both Table Mountain and Palomar at times,” said Ryan Rogalin, project receiver electronics lead at JPL. (While radio frequency communications can operate in most weather conditions, optical communications require relatively clear skies to transmit high-bandwidth data.)

Deep Space Station 13 at NASA's Goldstone Complex in California — part of the agency's Deep Space Network — is an experimental antenna retrofitted with an optical station. Initially, this proof of concept received radio frequency and laser signals from deep space at the same time. Image source: NASA/JPL-Caltech

JPL recently led an experiment to combine Palomar, an experimental radio-frequency optical antenna at DSN's Goldstone Deep Space Communications Complex in Barstow, California, and a detector at Table Mountain to receive the same signal in concert. “Arranging” multiple ground stations to mimic one large receiver can help boost the deep space signal. This strategy can also be useful if a ground station is forced to go offline due to weather conditions; Other stations can still receive the signal.

More about the mission

This demonstration, managed by JPL, is the latest in a series of optical communications experiments funded by NASA's Technology Demonstration Mission (TDM) program and the agency's SCaN (Space Communications and Navigation) program within the Space Operations Mission Directorate. Development of the aviation laser transceiver is supported by Massachusetts Institute of Technology Lincoln Laboratory, L3 Harris, CACI, First Mode, Controlled Dynamics Inc., Fibretek, Coherent, and Dotfast support ground systems. Some of this technology was developed through NASA's Small Business Innovation Research Program.

Arizona State University leads the Psyche mission. JPL is responsible for overall mission management, system engineering, integration and test, and mission operations. Psyche is the 14th mission selected as part of NASA's Exploration Program under the Science Mission Directorate, which is managed by the agency's Marshall Space Flight Center in Huntsville, Alabama. NASA's Launch Services Program, headquartered at the agency's Kennedy Space Center in Florida, managed the launch service. Maxar Technologies provided the high-energy solar electric propulsion spacecraft chassis from Palo Alto, California.