Two companies join SpaceX in the race to Mars, with a launch possible in 2024

Relativity Space has not launched a single rocket, and Impulse Space has never tested one of its thrusters in space. Nevertheless, on Tuesday, the two California-based companies declared their intention to launch an ambitious mission that will land on the surface of Mars in fewer than three years.

This would be the first commercial mission to Mars, and normally such a claim could be safely dismissed as absurd. But this announcement—audacious though it may be—is probably worth taking seriously because of the companies and players involved.

Founded in 2015, Relativity has raised more than $1 billion and should launch its small Terran 1 rocket later this year. The company, which seeks to 3D print the majority of its vehicles, is already deep into the development of the fully reusable Terran R rocket. This booster is intended to be somewhat more powerful than SpaceX's Falcon 9 and would carry the commercial mission to Mars. Relativity plans to have the Terran R rocket ready to launch in 2024, with the Mars payload flying on its debut mission in the late 2024 window to Mars.

Impulse Space is newer, at less than a year old, but not without experienced engineers. The company was founded by Tom Mueller, the first employee hired at SpaceX and leader of its propulsion department for more than a decade. His engines power the Falcon 9, Falcon Heavy, and Dragon vehicles. Mueller considers launch a "solved problem" and is developing a line of non-toxic, low-cost thrusters to serve the in-space propulsion market.

"This is a whole new era of spaceflight, and we want to be positioned to provide reliable, low-cost, in-space propulsion," Mueller said in an interview with Ars. "We want to do it all—orbital, lunar, interplanetary."

The mission’s conception

The Mars mission was conceived last year when Relativity's vice president of engineering and manufacturing, Zach Dunn, reached out to Mueller. The two were old colleagues. Mueller had hired Dunn at SpaceX back in 2006, where the intern was soon put in charge of engine testing and then the overall propulsion system for the company's early Falcon rockets. Relativity wanted to make a splash with its first Terran R mission, and Mueller embraced the challenge.

The companies devised a mission in which the Terran-R vehicle would boost a Mars Cruise Vehicle developed by Impulse Space into a trajectory toward Mars. Upon reaching the red planet, the lander would separate from the cruise stage. This lander would leverage aeroshell technology developed by NASA for its Mars Phoenix lander and other vehicles and use the same entry velocity and angle as the NASA missions. The Impulse Space lander would then land propulsively under the power of four thrusters, similar in action to a quadcopter. With this mission design, Impulse plans to deliver tens of kilograms of scientific payload to the Martian surface.