The Google Lunar XPrize, an ambitious $30 million competition to send a robot to the surface of the moon, will end without any of the teams able to meet the March 31 deadline, organizers said in a statement Tuesday.

After consulting with the five teams left in the competition, “we have concluded that no team will make a launch attempt to reach the moon by the March 31st, 2018 deadline,” founder Peter Diamandis and chief executive Marcus Shingles wrote in the statement. “This literal ‘moonshot’ is hard, and while we did expect a winner by now, due to the difficulties of fundraising, technical and regulatory challenges, the grand prize of the $30 [million] Google Lunar XPrize will go unclaimed.”

To win, contestants would have been required to land a spacecraft on the moon’s surface, travel at least 500 meters, and then transmit high-definition video and images back to Earth.

The end of the competition is a letdown and a sign of the difficulties of commercial space travel, despite the advancements of companies such as SpaceX. The Lunar XPrize was a follow-on to the Ansari X Prize, a $10 million contest captured by Paul Allen’s SpaceShipOne, which in 2004 became the first nongovernmental vehicle to make it past the edge of space.

Officials in the space industry had similar high hopes for the moon competition, and there were a few prospects that appeared to have good chances — chief among them a company called Moon Express.

In 2016, the Florida-based company became the first commercial entity granted permission from the Federal Aviation Administration to leave Earth’s orbit for deep space.

The company has said while it was competing in the XPrize, it would carry on with its plans to land on the moon.

“The competition was a sweetener in the landscape of our business case, but it’s never been the business case itself,” Bob Richards, the founder and chief executive of Moon Express said in a statement. “We continue to focus on our core business plans of collapsing the cost of access to the moon, our partnership with NASA and our long-term vision of unlocking lunar resources for the benefit of life on Earth and our future in space.”

Diamandis and Shingles said in the statement that XPrize is “exploring a number of ways to proceed from here. This may include finding a new title sponsor to provide a prize purse following in the footsteps of Google’s generosity, or continuing the Lunar XPrize as a non-cash competition.”