This space company is betting its future on a propellant available everywhere

What happened

Three brothers, Robert, Ryan, and Kirby Carlisle, left SpaceX in late 2022 and started Argo Space. Instead of building rockets, they chose to build spacecraft and space infrastructure. Their plan is to use water as the main fuel, or propellant, for moving in space. In July, the company flew its first test mission, called Navigator, on a Falcon 9 rideshare. The spacecraft made contact with controllers, but one of its two solar arrays did not open fully. This left it without enough power to test its propulsion system.

Key facts

• Founded in late 2022 by three brothers who once worked at SpaceX.
• The first demo mission, Navigator, flew in July on a Falcon 9 rideshare.
• The spacecraft had two rollout solar arrays. One failed to deploy.
• Controllers spent about half a day troubleshooting the problem.
• The spacecraft stayed power-negative, which means it used more power than it made, and its battery drained.

Why water?

Rockets usually carry all their fuel up from Earth, which is expensive. Water is found on the Moon and across the Solar System, so it could one day be collected there. Argo Space says water can do more than fuel. It can also cool the spacecraft's thrusters and electronics, and it can shield against radiation. Using more of the craft's weight for fuel helps it travel farther.

Why it matters

If the idea works, companies could refuel, repair, and move satellites between Earth orbit, a high orbit called geostationary orbit, and the Moon. This could make space logistics cheaper. The Navigator problem also shows how hard it is to test new space technology, because one failed part can stop the whole test.

What to watch

• Whether Argo Space can fix or work around the failed solar array on future missions.
• Whether the propulsion system can be tested using water.
• Whether the company wins customers for satellite refueling and repair.
• Whether water can later be harvested on the Moon at a useful cost.