Mission Summary
CAPSTONE was a CubeSat the size of a microwave oven, weighing just 25 kilograms, that flew ahead of NASA's Artemis program to test the unusual orbit chosen for the Gateway lunar station. The little spacecraft was built by Terran Orbital and operated for NASA by Advanced Space, a small company in Colorado. It launched on June 28, 2022 aboard a Rocket Lab Electron from Mahia, New Zealand, making the Electron the smallest rocket ever to send a spacecraft toward the Moon. Rather than flying directly, CAPSTONE took a slow, fuel-efficient ballistic transfer that carried it outward for four and a half months. On November 13, 2022, it became the first spacecraft ever to enter a near-rectilinear halo orbit.
The halo orbit passes close over one lunar pole and swings tens of thousands of kilometers beyond the other on each circuit. The path takes very little fuel to hold and keeps a constant line of sight to Earth, which is why NASA selected it for Gateway. CAPSTONE spent more than three years proving the orbit behaves as predicted. Along the way it tested autonomous navigation, fixing its position by crosslink with the Lunar Reconnaissance Orbiter, and survived a tumble that briefly cut communications during the cruise. NASA declared the mission complete on July 6, 2026, with every primary and extended objective met.
Sources and notes can be found on the Sources page.
