CAPSTONE’s CubeSat Prepares For Lunar Flight

CAPSTONE’s 12-Unit CubeSat nears completion. The spacecraft’s S-Band antenna is shown on the right side of the spacecraft. The 16 square-shaped elements on the surface of the flat plate are low-profile antennas, called patch antennas, that make up the S-Band antenna array. The antenna is integrated with the communications system structure. The red structures are handling fixtures that will be removed from the spacecraft prior to testing. Credits: Tyvak Nano-Satellite Systems, Inc.

Small spacecraft will play a big role in lunar exploration, including a Moon-bound CubeSat launching later this year.

The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, or CAPSTONE, mission team is making the final preparations for the spacecraft that will make CubeSat history over a series of technological and operational firsts for the small platform.

Planned for launch in 2021, CAPSTONE will fly in cislunar space – the orbital area near and around the Moon – and demonstrate an innovative spacecraft-to-spacecraft navigation technology. CAPSTONE also will test out a unique lunar orbit that Gateway will use as the Moon-orbiting outpost for NASA’s Artemis program.

CAPSTONE will use a hydrazine-fueled propulsion system during most of its three- to four- month journey to the Moon. This line of propulsion system, developed by Stellar Exploration Inc. of San Luis Obispo, California, is a recently developed and flight-proven system developed for use on CubeSats. The team recently completed a fueling and final test-fire of CAPSTONE’s propulsion system at Stellar Exploration’s facility and is integrating the system with the spacecraft.

But before CAPSTONE fires its own thrusters, Rocket Lab’s Electron rocket will launch the mission from Earth carrying the CAPSTONE spacecraft integrated onto its new Lunar Photon upper stage/spacecraft. For the mission, Lunar Photon will serve as an upper stage to get CAPSTONE to a highly efficient ballistic lunar transfer trajectory designed by Advanced Space of Colorado. About seven days after launch, after a series of orbit raising maneuvers and the final trans-lunar injection burn, Photon will release CAPSTONE. After the deep space, low energy transfer, the CAPSTONE spacecraft will insert itself into the near rectilinear halo orbit. At the same time, Lunar Photon will continue to a separate orbit for its safe disposal.

The CAPSTONE spacecraft is fast approaching completion. Near-term plans include continued integration, testing, and international shipment of the spacecraft in late September. Rocket Lab has identified its Launch Complex 1 in New Zealand as the CAPSTONE launch site. Onsite launch preparations will include checkouts and fueling of the CAPSTONE spacecraft and its subsequent integration with Photon.

In May 2021, New Zealand signed the Artemis Accords with NASA – a set of principles that reinforce and implement the 1967 Outer Space Treaty. The agency aims to assemble the broadest and most diverse international space exploration coalition in history. To date, 12 nations have signed the accords, and conversations with other nations are ongoing.