According to NASA's Dough Loverro, who oversees the agency's human exploration programs, several aspects of the project's technical design and multi-phase rollout need to be revised.

One of the first changes will affect NASA's touted Lunar Gateway, a space station planned to orbit the moon and to be used as a staging point for the subsequent construction of a base on the moon's surface.

NASA had targeted a completion window for the Lunar Gateway in 2024, and promised construction on the lunar base would begin no later than 2025, but according to a report in the Wall Street Journal, the Lunar Gateway is being reworked. 

NASA says it will still have a space station in orbit around the moon in 2024, but it won't initially be as capable as originally planned, likely delaying the completion date for the lunar base.

 The Gateway was also to be a launching point for NASA's later mission to Mars, planned for sometime in the 2030s, as well as a resource for commercial space travel companies like Elon Musk's SpaceX and Jeff Bezos's Blue Origin.