Racing for Earth's Future

The Earth Cup is a space race motivated by climate change challenges. The competition centers around the idea of solar sails. Modern spacecraft rely on propulsion to move through space. While the specific method varies, they all share one Achilles’ heel — fuel. The amount of fuel a spacecraft can carry directly limits the lifetime of modern space missions. Solar sails aim to shift away from this paradigm.

Rather than relying on traditional fuel sources, solar sails operate using photons from the sun. These sails must be extremely large, lightweight, and reflective so photons can bounce off their surface, transferring momentum that allows the spacecraft to maneuver through space.

The concept of solar sails dates back to the early 1900s, even appearing in science fiction in the 1950s and ’60s, but practical research has only recently become possible thanks to advances in materials and space-ready electronics.

Associate Professor Caverly is leading the group participating in the competition and is currently working on a NASA-sponsored project to design and validate a concept for controlling the attitude of these large, next-generation solar sails. He has seen firsthand the potential solar sails hold for future missions.

“With solar sails, there is no fuel limit,” said Caverly. “The intensity depends on how close you are to the sun and how the spacecraft is angled relative to it. This affects both the strength and direction of the momentum that allows you to move.”

Assistant Professor Damennick Henry is focused on understanding the spacecraft’s orbit and is working closely with Caverly to determine how orientation can be used to extend orbital lifetime and maintain altitude for as long as possible.

“On my side, it’s really about thinking through how to leverage the dynamics to get where you want to go, which is still crucial for solar sails,” he explained. “Even though we have some control authority, we still have to work with the natural dynamics to design the trajectory. In some sense, it’s this natural force that we have to understand and learn how to use.”

Extending mission duration is just one potential benefit of solar sails. They could also enable spacecraft to operate in regions that are inaccessible to traditional spacecraft.

“If we wanted to place a spacecraft between Earth and the sun to monitor phenomena like solar flares that can affect our satellites, we could get much closer using a solar sail,” said Henry. “There’s a balance between solar radiation pressure and the gravitational forces of the Earth and sun that allows a sail to essentially ‘hover’ — something a conventional spacecraft cannot do.”

While solar sails won’t replace traditional spacecraft, they could unlock entirely new types of missions that are currently impractical due to fuel constraints. Interstellar travel may even become more feasible, opening the possibility of visiting nearby star systems.

It may sound like something out of a movie, but Caverly and Henry believe competitions like the Earth Cup bring those ideas closer to reality.

“I think the really exciting thing about the competition is that we’re starting to chip away at challenges that once existed only in science fiction,” said Henry. “Having spacecraft that are more responsive to needs here on Earth opens up an entirely new way of thinking about space systems in general.”

The competition is centered on exploring the use of solar sails to block a small portion of sunlight, effectively acting as a thermostat to help lower Earth’s temperature. This approach has the advantage of being both adjustable and reversible.

To achieve this ambitious goal, the competition begins with a series of increasingly complex races designed to advance the technology while also building an international workforce capable of developing these systems.

The first phase involves creating an initial design, which will be evaluated before Caverly, Henry, and the rest of the team is selected to move forward to a flight scheduled for early 2027. 

The team, dubbed the Midwest Alliance for Solar Sail Technology, is made up of faculty members, students and researchers at the University of Minnesota and beyond.

Professor Demoz Gebre-Egziabher is focusing on navigation, developing strategies for onboard GPS systems; Assistant Professor Kshitiz Upadhyay is addressing structural challenges, applying his expertise in soft materials to ensure the sail remains lightweight yet durable during launch; and Professor Tom Schwartzentruber is modeling the aerodynamics of the low Earth orbit environment, including atom-level interactions to better understand drag on the vehicle.

“This competition brings together some of the biggest challenges in each of our fields,” said Caverly. “If we can solve these problems for solar sails, those solutions can extend far beyond this application, with major implications for aerospace engineering as a whole.”

The University of Minnesota team is also partnering with researchers from Missouri S&T and the University of Michigan, forming a collaboration that spans a wide range of expertise. Students will play an active role as well, assisting with the design and assembly of various components.

While the team has made strong progress toward the initial race, they recognize that continued success will require broader support.

“Looking ahead, future races will require us to tackle increasingly complex challenges,” said Caverly. “To do that, we’ll need large, capable teams.”

With many major space centers located on the coasts, Caverly and his colleagues see this effort as an opportunity to grow a strong aerospace workforce in the Midwest. A key part of that vision is engaging the broader community, from University of Minnesota alumni to regional industry leaders.

As the Earth Cup pushes solar sail technology from theory toward reality, the work being done by the Midwest Alliance for Solar Sail Technology is a tangible step toward addressing one of the world’s most pressing challenges. Advancing this effort will require collaboration beyond the lab. Alumni, industry partners, students, and community members all have a role to play in building the expertise, resources, and momentum needed to succeed. 
 

Join the Race

By getting involved through research partnerships, mentorship, funding, or advocacy, you can help propel this work forward and contribute to a future where space technology plays a critical role in protecting our planet.

Interested? Contact [email protected]