Two Companies Join SpaceX in the "Race" to Mars

We've talked about a startup called Relativity Space before, perhaps first back in 2019 when they secured a good chunk of funds for their development.  Relativity is dedicated to 3D printing their rocket and its engines. They still haven't launched the first flight of their planned Terran-1 rocket, but have leased launch complex 16 on Cape Canaveral and are working toward a first launch before the end of this year.  Their long range goal is a bigger rocket called Terran-R, with a larger payload capacity to orbit than a Falcon 9 but short of what a Starship can do.

Relativity announced they've partnered with another small startup company called Impulse Space, which emphasizes optimizing the small thrusters that seem to be needed pretty much everywhere in space operations.  Just as Relativity hasn't launched a Terran-1, Impulse hasn't put one of their thrusters into space.  

The two of them have teamed up to launch a satellite to land on Mars in the late 2024 launch window - from November of 2024 through April or May of 2025.  The planned launch to Mars will be the most ambitious first-flight of a rocket I can recall, but the intent is this will be the first launch of the Terran-R.

Founded in 2015, Relativity has raised more than $1 billion.  Impulse Space is rather different story.  The company 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.  The father of the Merlin engines, his Merlin engines power the Falcon 9, and Falcon Heavy.  Another of his engines powers the 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.

The two companies are connected in other ways.  Relativity's vice president of engineering and manufacturing, Zach Dunn and Mueller worked together at SpaceX.  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.  The Mars mission was born when Dunn reached out to Mueller.  

...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.

Did I say this was an ambitious first flight for a new rocket?  How about if I add that only NASA, China and Russia have landed probes on Mars - and Russia's 1971 Mars 3 probe stopped transmitting 14.5 seconds after its soft landing and was never heard from again (NASA speculated that they found it in 2013).  

"If it wasn't challenging, I wouldn't be doing it," Mueller said. "I always feel like if people aren't a little bit skeptical about what we're doing, we're not doing it right."

Relativity's chief executive and co-founder, Tim Ellis, echoed those words. He said he wanted to make a statement by putting a Mars-bound payload on the first launch of the Terran-R rocket. Ellis founded Relativity Space partly because he was inspired by what SpaceX and Elon Musk were trying to do to make humanity a multiplanetary species. This commercial mission, he said, would move the needle forward.

"We're big fans of SpaceX and Starship," Ellis said. "But there's got to be more than one company working at this. I want to be the second company that steps forward and says this is important. Hopefully there are many more."

Relativity Space's Terran-R preliminary design, from the company website.  

Relativity reports that development is going well and while it's aggressive to go to Mars in around 2-1/2 years, it's doable.  I wish them well but I'll feel more optimistic about the outlook when Terran-1 flies - and the sooner the better.  If space is hard and orbit is harder, interplanetary travel is step beyond that.