Advancing Deep Space Communications with Laser Technology: NASA’s DSOC Project

Scheduled for launch in the upcoming fall season, NASA’s Deep Space Optical Communications (DSOC) initiative is poised to investigate the potential of utilizing lasers to enhance data transmission within the realm of space exploration.

NASA is in the process of evaluating cutting-edge technologies both in space and on terra firma, with the aim of amplifying bandwidth capabilities for transmitting intricate scientific data and even enabling live video streaming from Mars.

The impending launch of NASA’s Deep Space Optical Communications (DSOC) undertaking this fall will undertake the task of evaluating the potential of lasers in drastically expediting data transmission rates, surpassing the capabilities of the current radio frequency systems employed in space missions. Functioning as a technology demonstration, the DSOC project holds the potential to establish the groundwork for broadband communications, a pivotal support system for NASA’s imminent momentous leap – the dispatch of astronauts to Mars.

The DSOC project will leverage a near-infrared laser transceiver (a device that both sends and receives data) affixed to NASA’s Psyche mission, set to embark on a journey to an asteroid named Psyche, rich in metallic content, in October. During the initial two years of this mission, the transceiver will establish communication with two ground stations located in Southern California. This endeavor will involve the testing of exquisitely sensitive detectors, potent laser transmitters, and novel techniques to decode the signals transmitted by the transceiver from the depths of space.

Signifying the Future of Communications

NASA is focusing its efforts on laser, or optical, communication due to its potential to outstrip the bandwidth capacity of radio waves, a technology that has been the staple of the space agency for over half a century. While both radio and near-infrared laser communications function by transmitting data through electromagnetic waves, the latter manages to pack data into considerably denser waves, thereby allowing ground stations to receive a larger volume of data in a single instance.

Abi Biswas, the project technologist for DSOC at NASA’s Jet Propulsion Laboratory in Southern California, elaborates on the project’s aspirations: “DSOC was conceived to showcase data-return capacities that are 10 to 100 times higher than the state-of-the-art radio systems currently employed in space. Although high-bandwidth laser communications for near-Earth orbit and Moon-orbiting satellites have been validated, the realm of deep space introduces novel challenges.”

In an era where deep space missions are more numerous than ever, poised to generate exponentially larger amounts of data encompassing complex scientific measurements, high-definition images, and videos, experiments such as DSOC play a pivotal role in propelling NASA’s technological advancements. These advancements are anticipated to become commonplace in the systems of spacecraft and ground stations in the years to come.

Promising Technological Frontiers

The transceiver embarking on the Psyche mission encompasses a range of innovative technologies, including a photon-counting camera that has never been deployed before. This camera is coupled with an 8.6-inch aperture telescope, which extends from the spacecraft’s side. The transceiver is equipped to autonomously search for and synchronize with the high-power near-infrared laser uplink transmitted by the Optical Communication Telescope Laboratory situated at JPL’s Table Mountain Facility in Wrightwood, California. This uplink laser will also showcase its capability to transmit commands to the transceiver.

Jason Mitchell, the program executive for NASA’s Space Communications and Navigation (SCaN) program, emphasizes the importance of the powerful uplink laser: “The high-power uplink laser is a crucial element of this technology demonstration, enabling higher data rates to spacecraft. Additionally, upgrades to our ground systems will pave the way for optical communications in future deep space missions.”

Once the transceiver successfully locks onto the uplink laser, it will align with the 200-inch Hale Telescope located at Caltech’s Palomar Observatory in San Diego County, California. The transceiver will employ its near-infrared laser to transmit data at high rates to the Palomar site. Advanced struts linking the transceiver to the Psyche spacecraft will mitigate the impact of spacecraft vibrations, which could otherwise disrupt the laser’s precise targeting.

To capture the high-rate downlink laser from the DSOC transceiver, the Hale Telescope has been outfitted with a pioneering superconducting nanowire single photon detector assembly. This assembly is maintained at cryogenic temperatures to detect and record the arrival time of individual laser photons – the quantum particles of light. The transmitted laser light, delivered in a sequence of pulses, must traverse over 200 million miles (300 million kilometers) – the greatest distance the spacecraft will attain during this tech demonstration. Only then can the faint signals be identified and processed to extract the underlying information.

Bill Klipstein, the DSOC project manager at JPL, underscores the revolutionary nature of each component of DSOC: “Every aspect of DSOC embodies new technology, from the potent uplink lasers to the targeting system on the transceiver’s telescope, extending to the remarkably sensitive detectors that can discern and count individual photons upon their arrival. The team had to develop innovative signal-processing techniques to extract information from these feeble signals, transmitted across vast cosmic distances.”

Navigating Challenges and Championing Innovation

The vast cosmic distances introduce yet another challenge for this technological demonstration: the duration it takes for photons to traverse these distances results in a time lag that can extend to tens of minutes. Given that both Earth and the spacecraft are in constant motion as the photons travel, compensating for this lag presents a formidable challenge.

Abi Biswas offers insight into this challenge: “The task of pointing the laser and establishing synchronization over millions of miles while simultaneously accounting for the dynamic movement of Earth and Psyche poses an exhilarating challenge for our project.”

A Glimpse into the Mission’s Future

The DSOC project is poised to operate for nearly two years subsequent to the launch of NASA’s Psyche mission, during its journey to a Mars flyby scheduled for 2026. While the DSOC transceiver will be a part of the Psyche spacecraft, its tech demonstration will not involve the relay of data from the Psyche mission. The success of each project will be evaluated independently of the other.

DSOC marks the latest installment in a series of optical communication demonstrations sponsored by the Technology Demonstrations Missions (TDM) program and the Space Communications and Navigation (SCaN) program. The Jet Propulsion Laboratory (JPL), a division of Caltech situated in Pasadena, California, is overseeing the DSOC initiative under the purview of TDM within NASA’s Space Technology Mission Directorate, as well as SCaN within the agency’s Space Operations Mission Directorate.

The Psyche mission is led by Arizona State University, with JPL taking charge of the mission’s comprehensive management, system engineering, integration and testing, and mission operations. Psyche forms part of NASA’s Discovery Program.

Frequently Asked Questions (FAQs) about Laser Communication

More about Laser Communication

• NASA Deep Space Optical Communications (DSOC) Project
• NASA Jet Propulsion Laboratory (JPL)
• NASA’s Space Technology Mission Directorate
• NASA’s Space Communications and Navigation (SCaN) Program
• NASA’s Discovery Program