Satellites will now be able to move without a single drop of fuel. A New Zealand start-up, Zenno Astronautics, has successfully tested a thruster that uses superconducting magnets to maintain a satellite's position in orbit. This technology, long considered too bulky and fragile for small spacecraft, has just crossed a major milestone.
This system, called Supertorquer, works by converting solar energy directly into motion. Superconducting magnets, powered by solar panels, generate a magnetic field that interacts with Earth's magnetic field. By controlling this field on board the satellite, engineers can orient the craft and accelerate it without having to burn propellant.
The Supertorquer system from Zenno Astronautics uses superconducting magnets powered by solar energy to generate thrust on board satellites. The device was recently tested in orbit.
Credit: Zenno Astronautics The main technical challenge lies in cooling the magnets. To become superconducting, they must be brought to -200°C. In space, while the environment is very cold, the satellite itself remains at about 20°C (68°F) due to the Sun. Engineers therefore designed efficient insulation and a heat pump that removes excess heat, allowing the magnets to operate without liquid cryogenics.
The first in-flight test took place on the Mira satellite, launched last November aboard a SpaceX mission. Since then, the Supertorquer, about the size of a shoebox, has demonstrated its effectiveness. Max Arshavsky, CEO of Zenno, explains that this technology avoids violent satellite movements and allows precise pointing, all without consuming a single drop of fuel.
Future applications are promising. The company plans to deploy more powerful systems to enable spacecraft to dock or maneuver in close proximity to one another. In the longer term, these magnets could propel vessels to the Moon and Mars, using only solar energy. Arshavsky even envisions magnetic shields protecting astronauts from cosmic radiation.
The ultimate goal is to reduce dependence on Earth-based resources to build a sustainable space industry. By transforming abundant solar energy into motive force, this innovation paves the way for longer and less expensive missions. A larger new demonstrator is scheduled for testing later this year.
Interaction with Earth's magnetic field
Earth has a magnetic field that extends well beyond the atmosphere. Any magnet placed in this field experiences a force: this is the principle of a compass. By controlling the orientation and intensity of the field produced by the superconducting magnets, the satellite can create a torque to rotate itself or a translational force.
The Supertorquer uses several magnets oriented along different axes. By selectively activating the magnets, it is possible to rotate the satellite around any axis or move it linearly. This system replaces chemical or ion thrusters.
The advantage is twofold: no fuel to carry, therefore less mass at launch, and no gas plume that could contaminate instruments. Furthermore, solar energy is inexhaustible as long as the Sun shines.