It’s like a confusing game of musical chairs for spacecraft.

Originally, the plan was straightforward: NASA wanted to send a rover to look for frozen water near the moon’s south pole. It hired a private company, Astrobotic Technology of Pittsburgh, to provide the spacecraft to land the rover on the moon’s surface.

The space agency’s strategy increasingly taps new entrepreneurial space companies to provide faster, cheaper solutions than what the agency could do itself.

But then in January last year, Astrobotic’s first lunar mission using a smaller lander failed to reach the moon.

Then, in July, NASA officials announced that they were canceling the ice-seeking mission known as the Volatiles Investigating Polar Exploration Rover, or VIPER.

NASA’s second thoughts about VIPER opened an opportunity for someone else to book that ride to the moon. Just because its cargo was canceled did not mean Astrobotic’s journey was off — it remains scheduled for later this year. And on Wednesday, a small startup named Venturi Astrolab Inc. announced it had claimed that opportunity to accelerate its own lunar rover plans.

“We’re excited to get actual wheels in the dirt this year and see how all our tech performs,” Jaret Matthews, the chief executive of Astrolab, said in an interview. (Despite the similar names, the two companies are unrelated.)