NASA has been leaning heavily on SpaceX in recent years, but when it comes to the future, the Space Launch System is the space agency’s biggest bet. The SLS is supposed to be the rocket platform that sends humans back to the Moon and deeper into our solar system. It’s also been delayed so many times that it’s hard to imagine it ever actually being completed.

Now, as Space News reports, the latest estimates put the debut launch of the SLS at some point in the second half of 2021. That’s a significant delay from recent NASA estimates and yet another sign that the troubling trend of delays seems to have no end.

For a long while, NASA was planning on a launch of the SLS coming in 2020. That timeframe was already a significant delay from earlier estimates, but NASA held on to that 2020 dream even after it became clear none of the pieces of the mission would come together in time.

When the current presidential administration mandated a crewed returned to the Moon by 2024, it wasn’t hard to find people who were highly skeptical that it could be pulled off in time. There are lots of moving pieces when it comes to a Moon mission, and adding human travelers to the mix multiplies the complexity many times over.

As NASA’s own rocket system continually gets pushed farther and farther back, it’s even harder to imagine any of this coming together in time. The Artemis missions will eventually happen, and NASA astronauts are certainly headed back to the Moon sooner rather than later, but if you’re still betting on a 2024 arrival, I wouldn’t hold your breath.

Mike Wehner has reported on technology and video games for the past decade, covering breaking news and trends in VR, wearables, smartphones, and future tech. Most recently, Mike served as Tech Editor at The Daily Dot, and has been featured in USA Today, Time.com, and countless other web and print outlets. His love of reporting is second only to his gaming addiction.