Black, windless, silent—low earth orbit seems empty. Yet as anyone launching a satellite in this region knows, powerful, invisible forces are at work. Gravity pulls the satellite towards earth, solar radiation generates its power, and earth’s magnetic field guides its trajectory.
IrishSat, the University of Notre Dame’s satellite and space engineering design team, has devised a mini-satellite that uses the earth’s magnetic field to orient itself with minimal use of energy—a key feature for small satellites that must generate power using tiny solar arrays. The team’s 0.5U satellite, which is about the size of a double-decker sandwich, will be deployed on SpaceX’s Transporter-16 mission in February 2026.
When separating from the rocket carrying it into orbit, a satellite is vulnerable to a tumbling motion that can prevent its antennae from locking onto earth and its solar panels from facing the sun. If a satellite fails to detumble and orient itself, its batteries will slowly drain, leading to a mission failure with no power for communications or science.
Most satellites rely on thrusters or reaction wheels to detumble, but IrishSat’s satellite, CHARMS, uses magnetorquers—metal rods wrapped with copper wire that create a magnetic field when an electrical current passes through them. By interacting with earth’s magnetic field, these magnetorquers allow the satellite to subtly adjust its position using electricity alone.
“The goal is to prove that with minimal inputs, our system can keep the satellite facing Earth,” said Jackson O’Neill, a senior majoring in aerospace engineering. “Our onboard cameras will verify that we’re achieving that orientation.”
The satellite’s payload, built entirely at Notre Dame, weighs just 300 grams—the weight of a large potato. It will ride into orbit aboard a satellite bus that provides power, communications, and thermal control.
The satellite bus is provided by NearSpace Launch, a small satellite company based in Upland, Indiana. The company’s nonprofit arm, NearSpace Education, is sponsoring IrishSat’s project as part of its Dream Big Program—a national STEM initiative that inspires students to build and launch high-altitude balloon and satellite projects. Five other universities will fly similar payloads on the same mission.
Notre Dame’s CHARMS is unique among the payloads in its focus on magnetorquer-based control, while other payloads are dedicated to earth-sensing applications such as imaging and infrared detection.
Beyond demonstrating their in-house magnetorquer system, the students hope this mission will pave the way for their next project, SHAMROCK, a larger 2U CubeSat carrying research from a Notre Dame professor. Success with CHARMS could strengthen their proposal for funding through NASA’s CubeSat Launch Initiative.
“There are always risks with first-time missions,” noted O’Neill, citing temperature extremes and algorithm challenges as key concerns. “But if we can prove reliable Earth-facing control, it will open the door for more affordable and accessible CubeSat research at the university level.”
After CHARMS is launched from Vandenberg Space Force Base in California and settles into orbit, data will be received and analyzed at Notre Dame, and posted on social media.
—Karla Cruise, Notre Dame Engineering