NASA's tiny CAPSTONE probe goes silent on its way to the moon

CAPSTONE in its halo-shaped lunar orbit.
Artist's illustration of NASA's tiny CAPSTONE probe in its halo-shaped lunar orbit. CAPSTONE is scheduled to arrive at the moon on Nov. 13, 2022, but that future is in doubt; mission team members lost contact with the cubesat shortly after it began flying freely on July 4. (Image credit: NASA/Daniel Rutter)

CAPSTONE has gone dark.

The 55-pound (25 kilograms) NASA probe ceased communicating with its handlers yesterday (July 4), shortly after it deployed successfully from Rocket Lab's Photon spacecraft bus and began its long trek to the moon.

"The spacecraft team currently is working to understand the cause and re-establish contact. The team has good trajectory data for the spacecraft based on the first full and second partial ground station pass with the Deep Space Network," NASA spokesperson Sarah Frazier wrote in an emailed statement today (July 5). 

"If needed, the mission has enough fuel to delay the initial post-separation trajectory correction maneuver for several days," Frazier added. "Additional updates will be provided as soon as possible."

Related: Why it'll take NASA's tiny CAPSTONE probe so long to reach the moon

CAPSTONE (short for "Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment") launched atop a Rocket Lab Electron booster on June 28 and spent nearly a week in Earth orbit, spiraling farther and farther away from our planet via occasional Photon engine burns.

The mission notched two huge milestones yesterday: The Photon fired its engine for a final time, accelerating CAPSTONE out of Earth orbit and on a path toward the moon. Shortly thereafter, the microwave-oven-sized cubesat successfully separated from the spacecraft bus and began flying freely.

If all goes according to plan, CAPSTONE will take a long, looping route to the moon, finally slipping into a near rectilinear halo orbit around Earth's natural satellite on Nov. 13. The mission's main goal is to test the stability of this highly elliptical orbit, which NASA has selected for its Gateway space station, a key piece of the agency's Artemis program of lunar exploration.

CAPSTONE will also conduct some navigation and communications tests during its time in lunar orbit, the latter trials performed in conjunction with NASA's Lunar Reconnaissance Orbiter, which has been circling the moon since 2009.

The CAPSTONE team will have to solve the communication problem to turn this vision into reality, however. That team is led by Colorado-based company Advanced Space, which operates the mission under a $20 million contract that NASA awarded in 2019.

Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or on Facebook.  

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Mike Wall
Senior Space Writer

Michael Wall is a Senior Space Writer with and joined the team in 2010. He primarily covers exoplanets, spaceflight and military space, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.