A small moon-bound spacecraft will wait at least a few more days to launch.
The launch of the CAPSTONE mission, short for “Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment,” has been delayed four days to no earlier than May 31, NASA announced this week.
“We will be continuously evaluating the date for the first target launch attempt within the launch window, which extends to June 22,” agency officials wrote Wednesday (May 11) in their blog for the Artemis lunar program. The post did not specify why the launch was slightly delayed.
The microwave-sized CAPSTONE spacecraft is launched from New Zealand aboard a Rocket Lab Electron rocket with a Lunar Photon upper stage. The mission is to verify the stability of a near rectilinear halo orbit (NRHO) around the moon, modeling what Gateway – the small lunar orbiting space station that is a key part of the Artemis plan – will to follow with astronauts on board.
Related: Rocket Lab and its Electron booster (photos)
The planned orbit will bring CAPSTONE within 1,000 miles (1,600 kilometers) of a closest lunar pole, and allow access to the south pole. That is the main target for the Artemis manned missions, given the likely presence of water ice in permanently shadowed polar craters.
At its highest elevation, CAPSTONE will swing 43 times higher to 43,500 miles (70,000 km). The advantage of such orbit is that future spacecraft coming to and from the lunar surface at the South Pole won’t have to fly that high to meet Gateway, but the halo orbit has not yet been tested by other spacecraft.
Complicating matters is that the moon has mascons (mass concentrations) that can disrupt orbits. So NASA seeks a cheap test before sending the much more expensive Gateway to such orbit.
CAPSTONE’s secondary mission is to assess spacecraft-to-spacecraft navigation and communications systems with NASA’s Lunar Reconnaissance Orbiter, which has been orbiting the moon since 2009. CAPSTONE was initially scheduled to fly in 2021, but the mission was postponed from then on due to COVID-related issues.