Powered by 48 AA batteries and a $20 microprocessor, a satellite shows a low-cost way to reduce space junk

Common sense suggests that space missions can only happen with multimillion-dollar budgets, materials designed to withstand extreme conditions outside Earth’s atmosphere, and as a result of work done by highly trained professionals.

But a team of engineering students from Brown University has turned that assumption on its head.

They built a satellite on a shoestring budget and using off-the-shelf supplies available at most hardware stores. They even sent the satellite—powered by 48 Energizer AA batteries and a $20 microprocessor popular with robotics enthusiasts—into space about 10 months ago, flying on an Elon Musk SpaceX rocket.

Now, a new analysis of data from the Air Force Space Command shows that not only did the satellite work successfully, but it could have far-reaching effects on efforts to reduce the growing space debris problem, which poses a potential danger to all future spacecraft.

According to NASA, there are now more than 27,000 pieces of what it calls orbital debris, or space junk, tracked by the Department of Defense’s Global Space Monitoring Network. Orbital debris ranges from any man-made object in Earth orbit that no longer serves a useful function, such as non-functioning spacecraft, abandoned launch stage vehicles, mission-related debris, and fragmented debris. It also includes defunct satellites that remain in orbit sometimes decades after their mission is completed.

That’s a problem, said Ric Flitter, assistant professor of engineering at Brown, given that most satellites stay in orbit for an average of 25 years or more. So when his students got the once-in-a-lifetime opportunity to design and build their own satellite to be launched into space, they decided to design a potential solution.

The students added a 3D-printed drag sail made of Kapton polyimide film to the loaf-sized cube-shaped satellite they built. Deployed at about 520 kilometers — well above the International Space Station’s orbit — the sail unfolded like a parachute and helped propel the satellite to Earth sooner, according to preliminary data. In fact, the Satellite is much smaller than the other small devices it has been deployed with. In early March, for example, the satellite was about 470 kilometers above Earth while other objects were still in orbit around 500 kilometers or more.

“You can see in the tracking data that we’re clearly lower than everyone else and accelerating away from them,” Flitter said. “You can see that our satellite is already descending towards re-entry, while the others are still in a nice circular orbit higher up.”

The data indicates that the students’ satellite, called SBUDNIC, will be out of orbit in five years as opposed to the 25 to 27 years the students calculated without the tractor.

Fleeter and Brown’s students believe their initial analysis of publicly available tracking data serves as a proof of concept that this type of sail could be part of an effort to reduce the number of space debris in orbit around Earth. They hope similar sails can be added to other rigs of similar size or scaled up for larger projects in the future.

“The theory and physics of how this works is well accepted,” Fletter said. “What this mission showed was more about how you realize it — how do you build a mechanism that does that, how do you do that, so it’s lightweight and small and affordable.”

The project is the result of a collaboration between researchers at the Brown School of Engineering and the National Research Council of Italy. It is also supported by D-Orbit, AMSAT-Italy, La Sapienza-University of Rome, and NASA Rhode Island Space Grant. The satellite’s name is a play on Sputnik, the first artificial satellite to orbit Earth, and it’s also an acronym for those involved in the project.

This is the second small satellite designed and built by Brown students that has been sent into orbit in recent years. The previous satellite, EQUiSat, made 14,000 loops around Earth before ending its mission and burning up as it re-entered the atmosphere at the end of 2020.

However, SBUDNIC is believed to be the first of its kind sent to an orbit made almost exclusively of materials not designed for use in space and at an astronomically low cost when compared to other objects in orbit. The total cost of the student-designed cube satellite was about $10,000.

The Great Complex space missions The news we’re hearing about is amazing and inspiring, Flitter said, but it also sends the message that the space is only for those kinds of niche initiatives. “Here, we’re opening that possibility up to more people…breaking down all the barriers, but you have to start somewhere.”

Designed by Brown University students

The satellite was designed and built in one year by a group of about 40 students – about half from the Brown School of Engineering with others from fields as diverse as economics, international relations and sculpture. I started on the ENGN 1760: Aerospace Systems Design course, which Fleeter took in the spring of 2021.

Italian aerospace company D-Orbit is close to opening a satellite on the SpaceX Falcon 9 rocket that will be launched within one year. Flitter turned to his students, who had just heard their first seminars on space systems design, and offered them an opportunity.

From there the race began.

Students began by conceptualizing and designing individual satellite subsystems, and often worked with industry consultants who provided engineering feedback and guidance on the feasibility of their proposals. The students then put their plans into action, managing the technical aspects of the satellite along with coordinating the administrative parts. The constant prototyping, testing, and improvement required has been a tremendous effort from the students in terms of hours and brain power.

said Marco Croce, who graduated from Brown University last year with a master’s degree in biomedical engineering and served as chief engineer for SBUDNIC.

The students purchased the materials they needed from local stores and online retail sites. They often had to design amazing solutions for their materials so they could survive in space. That approach, Cross said, often means coming up with test devices that simulate specific environmental conditions in space, such as the high vibrations from a rocket launch. For example, the team used reptilian heat lamps in a vacuum chamber to test the heat shield they had made to protect the satellite’s electronics from the sun.

To obtain permission to launch, the satellite had to pass qualification tests and comply with the strict rules and regulations followed by SpaceX and NASA. “It’s a no-fail environment,” Cross said. “The team never wavered.”

The students got the green light after a series of vacuum, heat and vibration tests. Then a group traveled to Cape Canaveral, Florida to deliver the SBUDNIC so it could be inserted into the larger D-Orbit. Satelliteswhich was then placed on a SpaceX rocket.

The students said that the project helped them think of themselves as creators and innovators, and that this experience is so ingrained in them that they will use the lessons well in the future.

“I went to use what I learned in this program to intern at Lockheed Martin Space,” said Celia Jindal, a Brown senior and one of the project leaders. “This project has really helped shape the way I see the world and has been very influential in shaping my university experience. This feeling is not unique to me. Many members of the team, like myself, joined SBUDNIC with no previous experience in the space industry and left to pursue paths in this We have SBUDNIC alumni across the industry — from pursuing a PhD to engineering at SpaceX.”

Besides presenting their findings at conferences and presenting their data to a publication, the SBUDNIC team is currently planning a series of presentations at schools throughout Rhode Island. They hope to inspire the innovators of the future and create the high school students More aware of the opportunities available to them in space architecture and design.