The $30 million Google Lunar XPRIZE was announced nearly a decade ago with the goal of landing a privately funded robot on the Moon that travels more than 500 meters and returns high-definition images and video to Earth. It had an ambitious timeline of just five years. But like almost all big projects in aerospace, this deadline kept slipping to the right. In 2015, it was extended to require a launch by the end of 2017.

By this year, five teams remained in the competition—SpaceIL, Moon Express, Synergy Moon, Team Indus, and Hakuto. Each had attained a contract to meet the requirement to launch a mission to land on the Moon by the end of this year to claim the bulk of the prize money. But still, no one seemed quite ready to launch to the Moon just yet.

In recognition of this, the prize organizers have extended the deadline for completion of the mission to March 31, 2018, giving each of the groups an additional three months. Organizers also added incremental prizes along the way, $1.75 million for completing one orbit around the Moon or entering a direct-ascent approach to the lunar surface, and $3 million for a soft landing on the Moon. The overall prize value remains $30 million.

“XPRIZE and Google are thrilled to offer these additional in-space Milestone Prizes as a further incentive for finalist teams and to recognize the full gravity of these bold technological feats taking place in the race to the Moon,” said Chanda Gonzales-Mowrer, senior director of the Google Lunar XPRIZE, in a news release.

The new milestone prizes seem to recognize that some companies may attempt to reach the Moon and fulfill the overall mission requirements but fail along the way. For example, a probe may go into orbit around the Moon but then lose communication. Or one might crash into the lunar surface. In this way, the prize organizers have given entrants a little more time—and some credit for partial achievements.

"The lunar arrival and soft landing milestone prizes are a great addition to the Google Lunar XPRIZE and are well aligned with major risk points of the competition," Bob Richards, founder and chief executive of Moon Express, told Ars. "Removing the constraint of a 2017 launch deadline is also a welcome development."