In a buzzing corner of campus, a group of students is pushing the limits of student-led space innovation. The newly established student organization, JHU CubeSat Club (HopSat), is gearing up to launch a nanosatellite powered by passive solar propulsion, with the ambitious goal of deploying the largest solar sail ever sent into space.
Small spacecraft (SmallSats) are spacecraft weighing less than 180 kilograms, but, even within this category, they come in various sizes and configurations. HopSat’s spacecraft is a 6U CubeSat, which fits within a 10-centimeter by 20-centimeter by 30-centimeter frame and weighs between one and 10 kilograms.
In an interview with The News-Letter, Arya Kazemnia, HopSat’s founder, and Neil Noronha, the organization’s structural lead and treasurer, explained the solar-sailing project and their vision for the team.
“The idea behind this satellite is to be the first group to launch a successful solar-sailing nanosatellite demonstrating a high degree of passive propulsion. The key is to use sunlight for thrust, propelling the spacecraft essentially for free by bouncing photons off the sail,” Kazemnia explained.
“What makes our mission ambitious is that we’re trying to escape Earth’s orbit. We’ll start in low Earth orbit, but the goal is to break free using only photon pressure, something that hasn’t been achieved yet with a solar sail,” Noronha added.
Since its founding, HopSat has attracted an interdisciplinary team of over 60 members, primarily freshmen and sophomores, with 12 in leadership roles and expertise spanning all engineering disciplines as well others, from physics to film and media studies.
The organization is divided into several specialized sub-teams: The sail team designs the reflective propulsion sail, the deployment team handles the sail deployment mechanism, and the on-board computer team ensures autonomous operation. The attitude determination control system team manages attitude control and navigation, the communication team oversees the satellite’s high-gain antenna for data transmission, the structural team designs the satellite bus, and the material analysis team will ensure all materials fare well in the harsh environment of space.
Kazemnia emphasized the importance of collaboration across sub-teams.
“During our general-body meetings, each team presents a report on what they've been doing that week, and other teams can ask questions. It’s a free forum for exchanging ideas, and we stay connected through open collaborative workspaces,” he said.
HopSat collaborates with mentors from Hopkins, NASA and other universities — including the Ames Research Center, the Johns Hopkins University Applied Physics Laboratory and the University of California, Los Angeles. The team also has members at other institutions such as the University of Maryland, College Park and the Olin College of Engineering.
Kazemnia, who spent four years working on NASA-related projects during high school, said his passion for space exploration inspired him to launch the group. Now pursuing degrees in biomedical and electrical engineering, Kazemnia balances leadership duties with technical contributions to the project.
"I want to work in the space industry; it’s incredibly exciting to be part of something that pushes the boundaries of what humanity can achieve," remarked Kazemnia.
Noronha, who is majoring in mechanical engineering, brings experience from a summer satellite engineering program at the Massachusetts Institute of Technology. He joined HopSat in August and now plays a role in both leadership and hands-on engineering. Noronha shared his and his teammates’ excitement for working on antenna systems and satellite networks.
“I love space and rocket science, and I could totally see myself doing that in the future,” he remarked.
The choice to build a 6U CubeSat reflects a balance between feasibility and ambition.
“A 12U satellite is way more expensive to launch — about half a million dollars. With 6U, we get the space we need without breaking the bank. If this works, scaling up will be much easier,” he explained.
Kazemnia compared the physics behind the solar sail to a boat sail, explaining its similarities to a sailboat, where, instead of wind, they are using sunlight to propel the satellite.
“Instead of the large cloth sails on sailboats use to catch the wind and move forward, our sail is a giant reflective sheet that catches sunlight. When photons hit the sail, they bounce off and transfer momentum — like when a ball bounces off a wall,“ he added. “Each impact nudges the satellite forward. Once deployed at an altitude of 400 to 500 kilometers, the SmallSat will rely entirely on photon pressure for propulsion, eliminating the need for fuel.”
Kazemnia also reflected on lessons learned from earlier, less-successful attempts at passive propulsion.
“Most CubeSats use mechanical systems, like tape measures, to deploy their sails, but those systems waste space and add complexity. We’re using a unique deployment system relying on shape memory alloys integrated within the sail itself, which allows us to maximize sail area while keeping the design compact,” he said.
The sail, once deployed, will span 20 by 20 meters, about the height of Wolman Hall.
“We have to go through some crazy origami to fold it down into 6U space,” Noronha remarked.
Their goal is more than ambitious. The team aims to achieve a remarkable thrust-to-mass ratio with their solar sail.
“Most solar sails operate at around 300 grams per square meter,” Kazemnia noted. “Our goal is to get that down to 40 grams or less.”
Currently in the design phase, HopSat plans to present a working prototype at the Johns Hopkins Engineering Design Day in the spring and to have a more refined version by November 2025. Kazemnia stated that they hope to have all their parts fabricated by that date.
Before launch, the SmallSat will undergo rigorous vibration, thermal and vacuum testing — procedures required by NASA to simulate the harsh environment of space. The students plan to launch their first satellite by the end of their senior year with at least a year of operation in orbit. Once the first satellite is mostly developed, the team hopes to kick off a second project within two years to maintain momentum.
With meetings every Sunday at 4 p.m. in Hackerman B17, the team continues to grow stronger, preparing for the challenges ahead. Towards the end of the interview, Kazemnia encapsulated the spirit that drives HopSat toward its ambitious goals.
“If we succeed, we will be the first and largest solar sail ever launched, pushing humanity closer towards the stars,” he stated.
