Imagine fueling rockets with something as simple as water. Sounds like science fiction, right? But that’s exactly what a bold startup is attempting to do—and it could revolutionize space exploration.
For decades, there’s been a quiet assumption at the heart of our space ambitions: if we can return to the moon, we’ll find ice. Break that ice into hydrogen and oxygen, and voilà—rocket fuel to propel us deeper into the solar system, maybe even to Mars. And if we reach Mars, we’ll repeat the process, using its ice and atmospheric carbon dioxide to fuel our return journey. It’s a plan that’s been floated since the Apollo era, championed by figures like former NASA administrator Bill Nelson and SpaceX’s Elon Musk. But here’s the catch: no one has ever successfully turned water into rocket fuel for a spacecraft of any significant size.
Enter General Galactic, a startup led by two ambitious engineers in their twenties, determined to change that. This fall, they plan to launch an 1,100-pound satellite powered exclusively by water as its propellant in orbit. If successful, this could not only solve the long-standing fuel problem but also make U.S. satellites more agile—a critical advantage as the possibility of space conflicts grows.
“Everyone talks about building moon bases or Mars colonies, but who’s footing the bill? How does it actually work?” asks Halen Mattison, General Galactic’s CEO. Their vision? “To build a gas station on Mars and eventually create a refueling network across space.”
But here’s where it gets controversial: While the idea is ambitious, the challenges are immense. Water isn’t ideal for either chemical or electrical propulsion, yet it might be just good enough for both. Unlike liquid methane, water doesn’t require extreme cooling or risk exploding, but it’s far from a perfect fuel. General Galactic plans to demonstrate both methods during their Trinity mission: using electrolysis to split water for chemical propulsion and converting oxygen into plasma for electric propulsion with a Hall thruster. The goal? To show they can provide both efficient maneuvering and rapid response—“more than just a burp in space,” as Mattison puts it.
This is particularly timely as Chinese and Russian satellites increasingly shadow American ones, raising concerns about satellite defense. General Galactic hopes to offer a solution, promising to increase a spacecraft’s Delta-V (total change in velocity) by five to ten times.
Mattison and his CTO, Luke Neise, met at Stanford and began tinkering with the idea while working for SpaceX and Varda Space. They devoured research, ran countless simulations, and eventually realized they had something unique. “This is pretty different. This is kind of exciting,” Mattison recalls. So far, they’ve raised $10 million—a modest sum in aerospace but enough to fund this mission.
And this is the part most people miss: The challenges are daunting. Ionized oxygen, for instance, is highly reactive and can corrode electrical systems. “It’s not an easy element to work with,” notes Ryan Conversano, a consultant and former JPL technologist. Meanwhile, the chemical propulsion system’s competitiveness remains uncertain once the added mass of the electrolysis system is factored in.
“It’s a clever idea for small satellites, but there are a lot of what-ifs,” says Mark Lewis, CEO of the Purdue Applied Research Institute. Yet, he believes it’s worth pursuing. If General Galactic succeeds, it could rewrite the playbook for missions to the moon and beyond.
What do you think? Is water-based rocket fuel the future of space exploration, or is this startup biting off more than it can chew? Let us know in the comments!
