The project team also commanded the transceiver to optically transmit Psyche-generated data. As Psyche transmitted data over its radio channel to NASA’s Deep Space Network (DSN), the optical communications system simultaneously transmitted some of the same data to the Hale Telescope at Caltech’s Palomar Observatory in San Diego County, California—the primary technology demonstration ground downlink station .
“After receiving the data from DSN and Palomar, we verified the optically transferred data at JPL,” said Ken Andrews, the project’s flight operations manager at JPL. “It was a small amount of data transferred down in a short period of time, but the fact that we are doing this now has exceeded all our expectations.”
Fun with lasers
After Psyche’s launch, the optical communications demo was initially used to downlink preloaded data, including the Taters the cat video. The project has since proven that the transceiver can receive data from the high-power uplink laser at JPL’s Table Mountain facility, near Wrightwood, California. Data can even be sent to the transceiver and then beamed back to Earth the same night, as the project proved in a recent “flip experiment.”
This experiment transmits test data – as well as digital photos of pets – to Psyche and back, a round trip of up to 280 million miles (450 million kilometers). It also linked large amounts of the technology demonstration’s own engineering data to study the characteristics of the optical communication link.
“We’ve learned a lot about how far we can push the system when we really have clear skies, although storms have occasionally disrupted operations at both Table Mountain and Palomar,” said Ryan Rogalin, the project’s receiver electronics manager at JPL. (While RF communications can operate in most weather conditions, optical communications require relatively clear skies to transmit high-bandwidth data.)
JPL recently led an experiment to combine Palomar, the 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 simultaneously. “Stacking” multiple ground stations to mimic a single large receiver can help amplify the signal in deep space. This strategy can also be useful if a ground station is forced to shut down due to weather conditions; other stations can still receive the signal.
More about the mission
Managed by JPL, this demonstration is the latest in a series of optical communications experiments funded by the Technology Demonstration Mission (TDM) program within NASA’s Space Mission Directorate and the agency’s SCaN (Space Communications and Navigation) program within the directorate for space operations missions. Development of the flight laser transceiver was supported by MIT Lincoln Laboratory, L3 Harris, CACI, First Mode and Controlled Dynamics Inc., and Fibertek, Coherent and Dotfast supported the ground systems. Some of the 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, systems engineering, integration and test, and mission operations. Psyche is the 14th mission selected as part of NASA’s Discovery Program under the Science Mission Directorate, managed by the Marshall Space Flight Center in Huntsville, Alabama. NASA’s Launch Program, based at the Kennedy Space Center in Florida, manages the launch service. Maxar Technologies provided the chassis of the high-powered solar electric propulsion spacecraft from Palo Alto, California.
For more information on the Laser Communications Demonstration, visit:
https://www.jpl.nasa.gov/missions/dsoc
