Communication Breakdown: It’s Always the Same …

CAPSTONE—an acronym for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment—is the first mission of NASA’s Artemis program, a multi-phase, multi-year endeavor undertaken for the noble purpose of returning human beings to Earth’s moon. 

Departing Earth from a New Zealand launch-site on 28 June 2022, the microwave-oven-sized CAPSTONE vehicle thundered space-ward atop  a Rocket Lab launch vehicle. 

After a gradual, six-day ascent into a lunar-transfer orbit, the spacecraft’s engine executed a trans-lunar injection burn, thereby starting CAPSTONE on its way to the moon. 

On 5 July 2022, NASA reported that contact with CAPSTONE had been lost. 

Tense hours ensued, during which the space agency’s engineers and flight controllers plied their collective know-how and determination to the business of reestablishing communication with the diminutive spacefarer. Finally, on Wednesday, 06 July, engineers raised CAPSTONE on NASA’s Deep-Space Network (DSN), an antenna array by which the agency maintains communication with and control over its deep-space and orbital assets. 

The communication gap precluded the execution of a planned, 05 July maneuver intended to refine the vehicle’s trajectory. Presently, CAPSTONE is awaiting the trajectory correction, but remains on the overall intended course for its ballistic lunar transfer.

CAPSTONE is a CubeSat— a class of miniaturized satellite consisting of varying combinations of ten-centimeter, cubical modules. CubeSats have a mass of no more than two-kilograms per cubic-unit and are most often constructed of commercial, off-the-shelf electronic components. To date, over 1,600 CubeSats have been flung into Earth orbit. 

For the duration of its journey to lunar orbit CAPSTONE will be reliant upon its own propulsion system and the sun’s gravity. 

Upon arriving at the moon, CAPSTONE will enter a near rectilinear halo orbit (NRHO)—a periodic, three-dimensional orbit around the point of gravitational equilibrium (Lagrange point) between two massive celestial bodies [the Earth and the Moon] and one small body [the CAPSTONE spacecraft]. 

If NASA’s ambitions are realized, CAPSTONE will stabilize in NRHO, and in so doing, validate orbital mechanics conducive to the eventual construction of a near-lunar space-station called Gateway. 

FMI: www.nasa.gov