NASA's New Experimental Antenna Successfully Tracks Deep Space Laser Signals.

 

Deep Space Station 13 at NASA’s Goldstone complex in California, a segment of the agency's Deep Space Network, achieves a groundbreaking milestone as an experimental antenna retrofitted with an optical terminal. In an unprecedented feat, this proof of concept successfully received both radio frequency and laser signals from deep space simultaneously.

The Deep Space Network's (DSN) hybrid antenna, equipped to receive both radio frequency and optical signals, achieved a remarkable milestone by tracking and decoding the downlink laser from DSOC aboard NASA’s Psyche mission. This experimental antenna's capability to seamlessly handle both radio frequency and near-infrared laser signals demonstrates the feasibility of retrofitting NASA's giant dish antennas for optical communications.

This advancement holds significance as optical communication, with its ability to pack more data into transmissions, opens up new possibilities for space exploration capabilities. Moreover, it proves instrumental in supporting the Deep Space Network amid growing demands on the network.

Seven Hexagonal Mirrors in Focus at Deep Space Station 13's Optical Terminal.

Deep Space Station 13's optical terminal utilizes seven hexagonal mirrors to capture signals from DSOC's downlink laser, reflecting light into a camera above, and transmitting the signal to a detector through an optical fiber system.

Operating since November 2023, the 34-meter Deep Space Station 13, a radio-frequency-optical-hybrid antenna, diligently tracks the downlink laser of NASA's Deep Space Optical Communications (DSOC) technology demonstration. This technology, hosted by the Psyche spacecraft launched on Oct. 13, 2023, showcases its flight laser transceiver.

Situated at the Goldstone Deep Space Communications Complex near Barstow, California, the hybrid antenna is distinct from the DSOC experiment. Managed by NASA's Jet Propulsion Laboratory in Southern California, the DSN, DSOC, and Psyche collectively contribute to advancing deep space communication capabilities.

According to Amy Smith, DSN deputy manager at JPL, our hybrid antenna has consistently locked onto and tracked the DSOC downlink since shortly after the tech demo's launch, demonstrating reliable performance. Moreover, it successfully received Psyche's radio frequency signal, marking a groundbreaking achievement in synchronous radio and optical frequency deep space communications.

In late 2023, the hybrid antenna downlinked data from 20 million miles away at an impressive rate of 15.63 megabits per second – a notable 40 times faster than radio frequency communications at that distance. On Jan. 1, 2024, the antenna achieved another milestone by downlinking a team photograph previously uploaded to DSOC before the launch of the Psyche spacecraft.

Deep Space Station 13's Hybrid Antenna Achieves Laser Tracking.

To capture the photons of the laser, the hybrid antenna employs seven ultra-precise segmented mirrors affixed to its curved surface. These mirrors, reminiscent of the hexagonal design in NASA's James Webb Space Telescope, replicate the light-collecting aperture of a 3.3-foot (1-meter) aperture telescope. Upon the arrival of laser photons at the antenna, each mirror skillfully reflects and redirects them to a high-exposure camera attached to the subreflector suspended above the dish's center.

The camera captures the laser signal, which is then transmitted through optical fiber feeding into a cryogenically cooled semiconducting nanowire single photon detector. This detector, crafted by JPL’s Microdevices Laboratory, mirrors the technology utilized at Caltech’s Palomar Observatory in San Diego County, California, serving as DSOC’s downlink ground station.

Barzia Tehrani, communications ground systems deputy manager and delivery manager for the hybrid antenna at JPL, describes it as a high-tolerance optical system constructed on a flexible 34-meter structure. The system employs mirrors, precise sensors, and cameras to actively align and guide the laser signal from deep space into a fiber that leads to the detector. Tehrani envisions the antenna's sensitivity being put to the test as it aims to detect the laser signal from Mars at its farthest point from Earth, which will occur in June as Psyche journeys toward the main asteroid belt between Mars and Jupiter for its exploration of the metal-rich asteroid Psyche.

The seven-segment reflector on the antenna serves as a proof of concept for a potentially scaled-up and more powerful version featuring 64 segments, equivalent to a 26-foot (8-meter) aperture telescope, paving the way for future applications.

Integrating Optical Frequencies into DSN's Global Antenna Network for Enhanced Efficiency and Resource Optimization.

DSOC is at the forefront, paving the way for advanced data-rate communications essential for transmitting intricate scientific data, high-definition imagery, and videos in preparation for humanity's ambitious journey to Mars. The recent tech demo achieved a groundbreaking milestone by streaming the first ultra-high-definition video from deep space, setting new records for bitrates.

To address the current limitations in optical ground infrastructure, a potential solution lies in retrofitting existing radio frequency antennas with optical terminals and developing purpose-built hybrid antennas. The DSN's expansive network includes 14 dishes strategically positioned across facilities in California, Madrid, and Canberra, Australia. Hybrid antennas offer a versatile approach, utilizing optical communications for high-volume data transmission while leveraging radio frequencies for less bandwidth-intensive tasks like telemetry, encompassing health and positional information.

For decades, the DSN has expanded by incorporating new radio frequencies into its massive antennas across the globe. Barzia Tehrani emphasizes that the logical evolution now is to integrate optical frequencies. This strategic move allows a single asset to multitask, transforming communication infrastructure into efficient highways. This not only optimizes resource utilization but also translates to significant savings in time and money, marking a pivotal shift in communication strategy for enhanced effectiveness.