Bold Steps Toward Space: How Juno Propulsion Helps Fuel the Space Economy

Alexis Harroun (Juno Propulsion, Cohort 2024)

What if revolutionizing rocket propulsion could unlock entirely new possibilities for space exploration?

That’s one of the questions that Alexis Haroun, CEO and founder of Juno Propulsion, is focused on. In her Activate Fellowship, she’s exploring one of the biggest opportunities (and challenges) in the aerospace industry: creating more efficient, cost-effective, and environmentally friendly rocket propulsion systems.

“At Juno Propulsion, we’re working on next-generation rocket propulsion,” Alexis says. “Getting to, from, and through space is still incredibly expensive and technologically limited. While progress has been made over the past 20 years, our current propulsion systems date back to the Apollo era. They’ve hit their theoretical limits. We need breakthroughs to open up the new space economy.”

Juno’s solution is nothing short of revolutionary. The company is developing a propulsion system that’s based on rotating detonation combustion. Unlike traditional rocket propulsion—which Alexis likens to the steady flame of a gas burner—this system uses controlled micro-explosions to release significantly more energy from the same amount of fuel. This leap in efficiency could dramatically lower costs and make space travel safer by replacing toxic, expensive fuels like hydrazine with more sustainable green alternatives.

For Alexis, the journey to this breakthrough began in the deserts of New Mexico, launching high-powered rockets as an undergraduate student. “I’ve been fascinated by rocket propulsion for as long as I can remember,” she says. “The technology is not just exciting to work on—it’s also a cornerstone for building the future of space exploration.”

True to form for Activate Fellows, Juno’s vision for impact extends far beyond rockets. Alexis envisions a better “road to space” that enables innovations like asteroid mining, lunar habitats, and orbital manufacturing. But her ambitions also reflect a commitment to improving life on Earth. “One of the most exciting long-term opportunities is using space to benefit life on our planet,” she says. “Imagine moving heavy manufacturing to the vacuum of space, eliminating the pollutants that harm our environment.”

Alexis’s fellowship with Activate has played a pivotal role in advancing Juno’s mission. “Activate has been transformative,” Alexis shares. “We’re light-years ahead of where we would have been without the funding and mentorship.” A recent highlight of her Activate Fellowship was a visit last fall to the White House Office of Science and Technology Policy, where she discussed the challenges and opportunities facing deep-tech startups in aerospace. “It was an incredible opportunity to communicate what our company and others like us need to succeed,” she says.

Juno’s immediate focus is on completing its first in-space propulsion prototype: a high-efficiency, green-propellant thruster. “Our next milestone is to build a complete propulsion system—from tank to thruster—and demonstrate it in an operational environment,” Alexis explains. The ultimate goal is flight heritage, proving the technology works in space. After that, Juno plans to scale production and deliver propulsion units to satellite manufacturers and others in the growing space economy.

The future Alexis envisions is both inspiring and grounded in practical innovation. By rethinking rocket propulsion, Juno Propulsion aims to make space exploration more accessible, sustainable, and impactful. “This is a critical piece of enabling humanity’s future in space,” she says. “And it’s about more than space. It’s about protecting and enhancing life on Earth.”

At Activate, we’re proud to support innovators like Alexis Haroun who are turning ambitious visions into tangible breakthroughs. Juno Propulsion is a testament to the power of science, investment in science entrepreneurs, and joint initiatives to drive scalability so we can redefine what’s possible.