There are many hypotheses about what capabilities will need to come online for the growing space industry to flourish, but two of the biggest concern in-space mobility and in-space refueling. To have a fully independent space economy, proponents argue, we’ll need to be able to move satellites around in space and we’ll need a way to refuel them.
Argo Space Corporation aims to contribute to both these capabilities with a reusable orbital transfer vehicle that can be refueled with water harvested from the moon. (Oh, and Argo Space wants to do the lunar water harvesting, too.)
The startup, which was founded by three brothers who all formerly worked at SpaceX, is developing an orbital transportation spacecraft called the Argonaut, named for the famous seafaring heroes of Greek mythology. Alongside this, Argo Space says it also developed a method to extract water from lunar regolith, which could then be used as part of an off-planet fuel-creation process.
Its long-term vision is to bring a true logistics vehicle to space: one that can take a customer payload to an intended orbit, refuel, then do it all over again.
“That’s more of a fundamental change in architecture,” Argo CEO Robert Carlisle said in a recent interview. “We’re not just building an expendable kick stage. Those have existed in some form for a long time. We’re really trying to say, let’s open up access to novel orbits for small and large spacecraft.”
The company closed a $2 million pre-seed round last April; even since then, competition on both the in-space mobility side and the lunar water extraction side has gotten hotter. But Carlisle said that it’s the integrated vision of a reusable, refuelable spacecraft that sets Argo apart from its peers.
Investors are behind this vision: Argo raised another $7.9 million led by Crosslink Capital, with participation from existing investors Stellar Ventures and Type One Ventures.
The ability to access different orbits and to have dynamic missions in space would be nothing less than revolutionary for spacecraft operations. Carlisle said the company has seen growing commercial demand for in-space mobility, so the bulk of the funding will go toward Argonaut development and fully fund a sub-scale demonstration mission that is planned to launch in the fourth quarter of next year. That mission is intended to demonstrate the Argonaut’s propulsion system and the high-delta V, or velocity change, capability operating beyond LEO.
“A differentiating capability for us is our unique propulsion system, and actually providing a lot of delta-V going out to MEO, GEO and cislunar space,” Carlisle said.
The Argonaut uses a water plasma thruster, a less common propulsion system that he said provides a “good balance” of thrust and efficiency. As the name suggests, the thruster uses water as a propellant; the water is then ionized into plasma to generate thrust. Using a system that is based around water is critical to the startup’s overall plan to refuel the Argonaut using water harvested on the moon.
Even after extracting the water, however, Argo Space will need to find a way to get it from the lunar surface to orbit. Carlisle admitted that exporting mass from the surface of the moon is a challenge: “Lunar export is definitely a challenging piece of the architecture for everyone right now, but several of the lander providers are talking about export capabilities. Blue Origin and SpaceX, they’re working primarily on human landing systems, so they have a much more intense and broad set of requirements related to that, but those guys and others are working on export capabilities as well.”
Although the Argonaut subscale demo mission is happening first, that doesn’t mean the lunar water extraction piece has been put on the back burner: Since closing its pre-seed round last April, the company has validated its novel lunar water extraction method using simulated regolith, showing it can extract water even when it is barely present: concentrations as low as 1 part per thousand.
In the nearer term, Carlisle said the company plans to refuel Argonauts using water launched from Earth, which would be retrieved by depots in low Earth orbit. These depots will look like a simpler, cheaper version of the Argonaut, he said.