As NASA prepares for a sustained human presence on the Moon, missions will increasingly require spacecraft that can navigate and communicate without a direct connection to Earth.

NASA’s Cislunar Autonomous Positioning System Navigation and Operations Technology Experiment, or CAPSTONE, validated and advanced these capabilities.

Designed to test and validate technologies in lunar orbit, CAPSTONE launched in June 2022 and became the first US commercial mission to the Moon. The spacecraft tested operations in three-body orbits around the Moon, using the combined gravity of the Earth and Moon to reduce the fuel needed to maintain a stable lunar trajectory. It became the first spacecraft to fly and characterize this orbit for future scientific and exploration missions. The microwave-sized spacecraft, owned and operated by Advanced Space, received a 15-month mission extension, becoming a testbed for advanced communications, networking, autonomous navigation and software-defined satellite technologies.

Instead of launching a new satellite, NASA’s Research and Technology Mission Directorate demonstrated that CAPSTONE’s existing hardware could host new applications after launch, transforming the spacecraft into a flexible and cost-effective lunar technology demonstration platform. NASA’s SCaN (Space Communications and Navigation) Division will now use the data to demonstrate innovative navigation and networking techniques in future experiments.

“Operating multiple experiments simultaneously aboard the same spacecraft allows NASA to evaluate how these technologies work together in a real lunar environment,” said Greg Stover, director of the Advanced Research and Technology Division within NASA’s Research and Technology Mission Directorate at NASA Headquarters in Washington. “Investments in autonomous operations and resilient communications infrastructure are essential to ensure US leadership as activity around the Moon continues to increase.”

Two experiments aboard CAPSTONE used software-defined infrastructure to advance two essential elements of future missions: autonomous navigation and deep space communications. Autonomous navigation, guidance and control, or autoNGC, software is designed to allow a spacecraft to determine where it is, where it is going, and how to get where it needs to be without waiting for instructions from the ground. While parts of the software had previously flown in Earth orbit, CAPSTONE marked the first time autoNGC was tested on the Moon.

“To really prove that something works, you have to fly it,” said Sun Hur-Diaz, principal investigator of the autoNGC technology development project at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The real environment is key.”

Sun Hur-Diaz

autoNGC Project Principal Investigator, NASA Goddard Space Flight Center

The researchers also evaluated the performance of autoNGC with limited contact with Earth. While NASA’s Deep Space Network antennas supported the Artemis II crewed test flight around the Moon, CAPSTONE’s communications window was reduced to just a few passes per week.

These gaps became one of the most valuable pieces of evidence in the experiment. Without data from Earth, autoNGC determined CAPSTONE’s location using an onboard star tracking camera to obtain images of the Moon, Earth, and other celestial bodies. The camera-based system, known as optical navigation, at times surpassed ground-based methods for real-time onboard navigation, advancing technologies for future deep space missions.

In addition to autonomous navigation testing, CAPSTONE also tested delay/interruption tolerant networking (DTN), a communications architecture designed for deep space. Unlike terrestrial Internet systems, deep space communications must work despite long delays and frequent signal outages. The DTN system addresses those challenges by storing information on the spacecraft when no connection is available and automatically forwarding it once communications are reestablished. With these demonstrations, CAPSTONE became the first to fly the latest DTN protocols beyond Earth orbit and the first to run them on NASA’s core flight system, an open source framework that can be deployed on any spacecraft.

In a demonstration, engineers began transmitting data from CAPSTONE to Earth, but the connection ended before the transfer was complete. The spacecraft stored the remaining data until the next communication opportunity and transmission resumed automatically. Every piece of information hit home.

“You can imagine an astronaut walking behind a lunar hill or descending into a crater and temporarily losing connectivity,” said Ben Anderson, Near Space Network systems engineer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This technology allows data to be automatically retransmitted once communications are reestablished.”

In addition to its major achievements, CAPSTONE’s second life as a software-defined test platform demonstrated that new technologies can be tested affordably and directly in their operating environment.

After nearly four years of technological maturation, NASA’s activities on CAPSTONE concluded in June 2026, while Advanced Space will continue to use the spacecraft as a technology development testbed.

The CAPSTONE spacecraft was designed and built by Terran Orbital and is owned and operated by Advanced Space. NASA’s Research and Technology Mission Directorate managed the mission through the Small Spacecraft and Distributed Systems program, based at NASA’s Ames Research Center in Silicon Valley, California. Elements of the CAPSTONE technology suite were supported by NASA’s Small Business Innovation Research program. The autoNGC and DTN demonstrations conducted during the extended CAPSTONE mission were managed by NASA’s SCaN Division, based at NASA Headquarters in Washington.