NASA’s Deep Space Network (DSN) is a global array of deep space communications antennas that play a crucial role in facilitating communication between spacecraft and Earth. The network has been pushed to its limits in recent years, particularly during the Artemis I mission nearly four years ago.
During this time, the DSN struggled to keep up with the routine demands of 40 robotic science missions, as well as the extraordinary surge required by NASA’s Orion space capsule as it flew around the Moon. The experience was a wake-up call for NASA, highlighting the need for more capacity and better management of the network.
The agency has been working to address these issues, and the recent Artemis II mission provided an opportunity to test its new processes and infrastructure. The good news is that the DSN performed well during Artemis II, which was a significant achievement considering the high demand for data from the Orion spacecraft.
According to Greg Heckler, deputy program manager for capability development in NASA’s Space Communications and Navigation Program, the agency learned a lot from Artemis I and put new processes in place ahead of Artemis II. These changes focused on coordination and scheduling, which helped alleviate some of the pressure on the network. The science division provided positive feedback after Artemis II, indicating that the new approach was effective.
However, the limitations of the DSN remain a concern. With numerous missions planned for the Moon in the coming years, including those from commercial providers and international partners, the demand for signal is only going up. NASA is working to address this challenge by developing a dedicated network for Moon missions called Lunar Exploration Ground Sites (LEGS), which will free up more capacity on the DSN.
Another solution being explored is the use of data relay satellites that will fly in orbit around the Moon, supporting future landers and construction of a Moon Base. High-bandwidth optical communications may also be used to alleviate some of the pressure on the network. NASA successfully tested a laser communications terminal on the Orion spacecraft during Artemis II, which is an encouraging development.
The burden currently includes around 40 operating missions that rely on the DSN’s antennas in California, Spain, and Australia to stay in communication with Earth. Most of NASA’s missions outlive their original design lives, so they put demand on the network for longer as the agency launches new spacecraft. About 40 more missions are projected to need the DSN over the next 10 years, and many of the 40 missions currently using time on the network will likely still be operating over that time.
One of NASA’s most data-intensive missions, the Nancy Grace Roman Space Telescope, is scheduled for launch in August. It will return more data through the DSN than all of NASA’s previous astrophysics missions combined. The 10 CubeSats that launched as secondary payloads on Artemis I placed an unforeseen burden on the DSN. Some of the small satellites were lost soon after deploying from the rocket, and their operators called upon the DSN to use its giant antennas to search for the CubeSats as they headed into deep space.
To mitigate these challenges, NASA is now strictly requiring a feasibility study before onboarding new missions to the DSN. This will help balance the new demands coming onto the system versus those legacy missions that need to be supported until they fly out due to natural causes. The agency is also working with older missions to understand how much capacity they will use.
The accident last year that knocked one of the network’s three 70-meter (230-foot) antennas offline at the Goldstone Deep Space Communications Complex in California has further highlighted the need for better management and infrastructure.
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