The launch of NASA's CAPSTONE moon mission has been pushed back another week, to no earlier than June 13.
The 55-pound (25 kilograms) CAPSTONE spacecraft will lift off atop a Rocket Lab Electron booster equipped with a Lunar Photon upper stage, soaring into space from Rocket Lab's Zealand launch site.
That liftoff had been targeted for June 6. But CAPSTONE (short for "Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment") will now get off the ground no earlier than June 13, Rocket Lab said via Twitter on Tuesday (opens in new tab) (May 31), explaining that extra time is needed "to support final launch and Photon readiness checks."
Related: Rocket Lab and its Electron booster (photos)
This is the second launch delay for CAPSTONE within the last two weeks. The cubesat had been scheduled to fly on May 31, but NASA announced on May 20 that the target date had shifted to June 6, without explaining why.
The mission still has some wiggle room left, however; CAPSTONE's launch window runs through June 22.
CAPSTONE's main goal is to test out the stability of a near rectilinear halo orbit (NRHO) around the moon, making sure it's a safe place for NASA's forthcoming Gateway space station — a key component of the agency's Artemis moon program — to set up shop.
That highly elliptical orbit will take CAPSTONE, and Gateway, as close as 1,000 miles (1,600 kilometers) to the lunar south pole, and as far away from the moon as 43,500 miles (70,000 km).
CAPSTONE will also conduct some navigation and communications tests with NASA's Lunar Reconnaissance Orbiter, which has been circling Earth's nearest neighbor since 2009.
Mike Wall is the author of "Out There (opens in new tab)" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall (opens in new tab). Follow us on Twitter @Spacedotcom (opens in new tab) or on Facebook (opens in new tab).