NASA Artemis II mission gives Kerbal Space Program huge boost on Steam

In early April, NASA and its Artemis II mission inspired humanity to look toward the heavens. Now that the four-person space crew has returned home, however, the public still hasn’t had its fill of space travel. At least, that seems to be the only thing that can explain why, in 2026, Kerbal Space Program has rocketed back up in popularity. It’s been a decade since the beloved flight simulation game originally released for PC.

Kerbal Space Program is an engineering management game that turns players into rocket scientists by letting them build and fly spaceships. Fans figure out how to reach space by tinkering with components based on hardware used by astronauts or by recreating historically significant missions. The name Kerbal comes from the small green aliens that players direct as they build aircraft and perform experiments. The space game is realistic enough that even people at NASA are big fans.

Kerbal Space Program is widely considered a classic; Polygon ranked it among the 100 best games of the decade. Critically, though, KSP has not received an update since 2023, when it got a small patch. What’s more, the series has a poorly received sequel, and the original developers sold the rights years ago. KSP is also not currently on sale at a discount. Despite having no immediately obvious reason to return to the game, Kerbal Space Program has spent the last few days topping the Steam sales charts.

What’s even more shocking is that Kerbal Space Program hit an all-time peak for concurrent players on April 10 — meaning there are more players taking up video game rocket science now than there were when KSP launched or when it received meaningful updates. As of this writing, that peak sits at 21,037 players, according to SteamDB. KSP‘s concurrent player count right now is up to 14,658, which means that the old space game has more people playing it on Steam than there are people on the same platform playing Marathon, a high-profile release from 2026.

Appropriately, a number of Kerbal Space Program‘s recently-posted reviews make some sort of mention of landing on Earth’s moon. While many of these players blasting off into space are returning fans, a decent percentage appear to be brand-new fans who are only now discovering that rocket science is no joke. And at least some of those people are finding this out after downloading a recent mod that imports the Artemis II ship into the game.

“Building a plane is hard,” one recent review laments. Another player who left a positive KSP review says, “i have 0 clue what the ♥♥♥♥ im doing.” One KSP fan who has logged 193 hours in the game wrote on April 13 that, despite all that time, they have barely reached orbit.

Folks were already wowed by all the stories and images hailing from the Artemis II mission, sure. I’m betting that Kerbal Space Program players dipping their toes in now probably have a deeper appreciation of how monumental it is to reach a new record distance in outer space.

The original Kerbal Space Program is available on Linux, Mac, PlayStation 4, PlayStation 5, Windows PC, Xbox One, and Xbox Series X, if you want to give your rocket-building skills a shot.