CAPSTONE: The Microwave Oven Sized Pathfinder

The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, better known as CAPSTONE, is NASA’s latest spacecraft to head for the Moon, and one of the pioneering missions of the Artemis program. Set to enter the same orbit as the future Gateway Space Station, the small satellite’s goal is to test and demonstrate the stability of the Near Rectilinear Halo Orbit (NRHO). The microwave oven sized spacecraft launched from Launch Complex 1 on the Mahia Peninsula in New Zealand just last week on June 28th on top of Rocketlab’s Electron rocket.

Designed and built by Tyvak Nano-Satellite Systems on the 12U cubesat bus system with the propulsion system being built by Stellar Exploration Inc. the cost for the 9 month long CAPSTONE mission totaled $23.65 million. While being described as a pathfinder, the spacecraft’s objectives are to study the stability and dynamics of the Near Rectilinear Halo Orbit around the Moon, which will bring it within 1,000 miles of the Lunar north Pole at the closest pass every six and a half days, and over 45,000 miles above the Lunar South pole at the furthest.  It will also serve to demonstrate the use of cubesat technology for space exploration beyond near-Earth operations. It also aims to demonstrate spacecraft-to-spacecraft navigation and positioning by communicating with the Lunar Reconnaissance Orbiter(LRO) through its Cislunar Autonomous Positioning System(CAPS), bypassing the need for full time contact with Earth. 

The launch aboard Electron demonstrated the versatility of the rocket and its Lunar Photon second stage, sending the satellite on a ballistic transfer to the Moon. In the days following launch, Photon began conducting its 7 burns to raise the orbit of the spacecraft higher to a final apogee of around 810,000 miles from Earth, after which CAPSTONE departed from low-Earth Orbit and deployed from Photon. Flight of the spacecraft was then handed over to the teams at Terran Orbital and Advance Space who own and operate the satellite for NASA. 

Following a successful initial deployment on July 4th, including deployment of its solar arrays, NASA lost contact with the satellite through the Deep Space Network (DSN). This delayed the first course correction maneuver which was scheduled for July 5th. NASA eventually re-established contact with the satellite through the DSN on July 6th and determined that the spacecraft was still in good health. Upon investigation it was determined the communications drop came about due to a flight software issue which caused the radio to be inoperable. After regaining contact, the delayed first course correction maneuver was rescheduled and successfully carried out the morning of July 7th, and as of July 9th teams have stood down from the second in favor of analyzing data on the spacecraft’s performance as the first course correction had completed 90% of planned objectives so far. Being one of the first steps in the Artemis program, the spacecraft will be paving the path forward for future orbital Lunar operations, as well as future exploration of the solar system. It also will serve as an example of working commercial partnerships for deep space exploration and will set the foundations for those sorts of partnerships in the future. The CAPSTONE spacecraft is expected to enter its final orbit around the Moon on November 13th of this year. 

Edited by Derek Newsome.