NASA on Tuesday announced plans for three uncrewed missions to the moon later this year that will serve as early steps toward the long-term goal of building a permanent base on the lunar surface.

During these missions — all robotic flights — NASA aims to scout locations at the moon’s South Pole, gather scientific data, test technologies and prepare for the return of its astronauts to the lunar surface.

“We are not jumping right into the glass dome moon base,” NASA Administrator Jared Isaacman said Tuesday in a news briefing. “We intend to take an iterative approach, sending a demand signal to industry for a lot of landers and rovers and tech demonstrations, and all the scientific payloads these missions can accommodate.”

The newly announced missions, known as Moon Base 1, Moon Base 2 and Moon Base 3, are all slated to launch by the end of this year. The first is scheduled for no earlier than this fall, Isaacman said.

Jeff Bezos’ Blue Origin is set to play a major role in that first mission. NASA awarded the company a contract to carry two science and technology payloads to the moon using its lunar lander.

All three flights are part of the first phase of NASA’s long-term plan to build a base on the moon. That initial phase is expected to last through 2029. Then during the second phase, from 2029 to 2032, NASA plans to assemble semi-permanent facilities to enable early habitation on the moon.

By the third phase, starting in 2032, the agency said it aims to achieve a sustained presence on the lunar surface. Carlos Garcia-Galan, NASA’s MoonBase program manager, said Tuesday that the base could cover “hundreds of square miles.” By that time, NASA officials said they envision regular rotations of crews coming and going from the moon, with continuous activity on the lunar surface.

The agency’s moon base plans are meant to be executed in tandem with its Artemis return-to-the-moon program. Last month, the Artemis II mission sent four astronauts on a 10-day journey around Earth and the moon — NASA’s first moonbound mission in more than 50 years.

Next, NASA aims to launch the Artemis III mission in 2027 to conduct technology demonstrations in low-Earth orbit with one or both of the lunar landers that Blue Origin and SpaceX are each developing. If that’s successful, NASA plans to launch the Artemis IV mission to land astronauts on the moon in 2028.