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Impulse Space, the California-based venture founded by veteran SpaceX engineer Tom Mueller, today unveiled its proposed architecture for delivering medium-sized payloads to the moon by as early as 2028.

In a blog post, Mueller said the plan would fill a "critical gap in lunar cargo delivery capabilities."

Mueller was Employee No. 1 at Elon Musk's SpaceX, and is widely credited as the rocket scientist behind SpaceX's success. He left the company in 2020 to found Impulse Space, which is focusing on ways to improve mobility in space.

Impulse's Mira space tug has already demonstrated its capabilities in two LEO Express missions that took place in low Earth orbit in 2023 and 2025. The company is also developing a kick stage known as Helios, which would be capable of sending payloads to higher orbits.

"So far, Impulse's mission has unfolded in the orbits closest to Earth, but our work to improve in-space mobility doesn't end at geostationary orbit," Mueller wrote. "That's why we're unveiling some of our initial plans for the next stages of our roadmap, starting with the moon."

The roadmap envisions creating a lunar lander that would piggyback on Impulse's Helios kick stage. In the first stage of the journey, the mated payloads would be launched into low Earth orbit on a medium- or heavy-lift rocket. Then Helios would fire up its engine for a weeklong cruise from Earth orbit to low lunar orbit. The last stage of the journey calls for the lander to separate from Helios and descend to the lunar surface.

Mueller said the lander would fill a gap in the market for lunar deliveries, in the range of 0.5 to 13 tons of payload. "These sorts of deliveries could include things like a lunar terrain vehicle, rovers, communication relay systems, power generators and habitation modules," he wrote.

That's a niche between the small-scale deliveries that can be made by spacecraft such as Astrobotic's Griffin lander (625 kilograms) and Intuitive Machines' Nova-C lander (130 kilograms) on one hand, and crew-capable landers such as SpaceX's Starship (100 tons) and Blue Origin's Blue Moon Mark 2 (30 tons) on the other hand.

For what it's worth, Blue Origin's Blue Moon Mark 1 cargo lander is designed to send up to 3 tons of payload, which sits within the mass range that Mueller mentioned. Blue Origin is expected to launch its first Mark 1 mission to the moon next year.

Mueller said the Helios kick stage "is already well into development, with the first flight slated for late next year." Impulse has also begun work on the engine for the lunar lander. That engine will use a nitrous and ethane bipropellant, "the same combination used successfully in space on Mira," Mueller said.

"With this Helios and Impulse-made lander combination, we estimate delivering up to 6 tons of payload mass to the moon (across two missions) per year starting in 2028 at a cost-effective price point," Mueller wrote. "Each Helios + lander combo would take approximately 3 tons of cargo to the moon."

Mueller said Impulse was getting into the lunar delivery business to support "a sustained human presence in space—which, in turn, could function as a staging ground for future missions deeper into the solar system." He also noted that the moon offered potentially valuable resources such as helium-3 that could be sent back down to Earth.

NASA and the White House have made it clear that "returning a human presence to the moon is imperative to maintaining and expanding American leadership in space," Mueller noted. Although Mueller didn't directly address whether NASA has taken an interest in what Impulse plans to offer, it's likely that the company will be eligible for a healthy share of cargo delivery contracts if it follows through.

The moon isn't the only off-Earth destination that Impulse Space has targeted. Three years ago, Impulse and Relativity Space announced a partnership that's aimed at sending a lander to Mars by 2029. The connection between deliveries to the moon and deliveries to Mars may well be the subject of one of Mueller's future blog postings.