Today, Mars One announced a five-year delay to its projected timeline for starting a human colony on Mars, claiming it will now send the first crews to the planet in 2031; its previous target date was 2026. The Dutch-based venture, which promises people a chance to live out their remaining days on the Red Planet, said its roadmap had to be adjusted in order to give the venture more time to raise money, as well as push the “large expenses associated with the mission hardware back in time,” according to CEO Bas Lansdorp.

The project has been slower to get off the ground than Mars One anticipated, Landsdorp said. “Of course the whole Mars One team would have preferred to be able to stick to the original schedule, but this new timeline significantly improves our odds of successfully achieving this mission roadmap,” he said in statement.

Mars One has been constantly shifting its timelines

Mars One has been constantly shifting its timelines since it was first announced in 2012. And public scrutiny has suggested its mission may not be feasible. In 2014, two MIT graduate students released a report analyzing the plans for the Mars One colony, arguing it will take a significant amount of money and technological innovations for the project to work. The mission would likely be fatal for any potential colonists, the report found. Separately, Mars One has also been accused of potentially misleading the public about its finances and the amount of applicants it received.

The initial timeline for the Mars One mission was incredibly ambitious. It called for sending a communications satellite into Mars orbit sometime this year and then a Martian rover in 2018, which would help select the site for the colony. The rest of the hardware needed for the settlement would then be shipped over a couple years later, and the first crew of four would take off in 2022 for a 2023 arrival. After the first colonists arrived, crews of four would then launch to Mars every two years indefinitely.

These planned missions haven’t changed much since the initial announcement — except in terms of target dates. Now, the communications satellite isn’t supposed to launch until 2024 and the first rover will head to the planet in 2026. The rest of the hardware will then go to Mars three years later in 2029, followed by the first crew launch in 2031.

Crew training plans appear to have changed as well

Crew training plans appear to have changed as well. The crews selected for the trip were originally meant to begin training last year. Mars One said today that 100 finalists will be whittled to 12 to 48 people, or three to six groups of four crew members. Those people will start training in 2018 — a process that is supposed to continue until 2031. During that time, people who drop out will be “replaced by new crews from regular astronaut selection programs,” with “regular” meaning routine, according to Mars One. The company has weathered criticism for having very dubious criteria for selecting astronauts.

Aside from mission dates, Mars One has yet to offer some critical information about its plans — most notably, how it’s going to get to Mars. It anticipates using SpaceX’s Falcon Heavy (which hasn’t flown yet), but there are few details about the spacecraft that will take people to the planet. Plus, Mars One hasn’t accurately explained how the colonists are going to land on the Martian surface intact or the habitats they’ll live in if they survive the descent.

There’s the matter of funding also: it’s difficult to estimate what a Mars mission will cost, but experts have speculated anywhere from hundreds of billions of dollars to even more than $1 trillion will be needed. Lansdorp has often proclaimed that Mars One will raise all the money it needs through a reality TV show, which will document the colonists’ training and journeys to Mars.

Mars One was recently acquired by Switzerland-based company InFin Innovative Finance AG, allowing the organization to be listed on the Frankfurt Stock Exchange. The move allows Mars One to raise capital directly from the exchange rather than from private investors, the company said in a statement. The organization is trying to raise more than $10 million in its first round of funding after being acquired, according to today’s announcement.

Update December 7th, 3:51PM ET: This article has been updated to include clarification from Mars One about its astronaut selection program.