Zenno Supertorquer integrated on Portal Space's Starburst-1 craft
Zenno Astronautics has confirmed its Supertorquer superconducting magnetic actuator is fully integrated aboard Portal Space Systems' Starburst-1 spacecraft, with the vehicle described as weeks from shipping to its launch site. The announcement marks the first public unveiling of Starburst-1, a maneuverable spacecraft designed for rapid repositioning missions serving defence and commercial customers.
The Supertorquer operates by generating a magnetic dipole of up to 3,500 ampere-metres squared (A·m²), interacting with Earth's natural magnetic field to orient the spacecraft without consuming chemical propellant. Conventional spacecraft attitude control, managing a vehicle's pointing direction, relies either on reaction wheels, which have finite operating lives, or on propellant, which competes directly with the fuel budget reserved for orbital manoeuvring. Zenno's system draws on solar power rather than a consumable, meaning Starburst-1 can theoretically reserve its entire propellant supply for changing orbits rather than pointing.
The hardware
The Supertorquer previously achieved its first flight heritage aboard an Impulse Space mission, following a partnership announced in November 2025. Starburst-1 represents the system's second orbital demonstration and its first integration on a spacecraft explicitly built around high-cadence manoeuvring. Starburst-1's primary campaign is planned to run for one year and will also validate subsystems shared with Portal's larger trans-orbital vehicle, Supernova, including high-performance reaction control thrusters that serve as the craft's main translational propulsion.
Zenno co-founder and chief executive Max Arshavsky said the team is about to demonstrate "fuel-free control authority at this power level" in orbit for the first time. Portal chief executive Jeff Thornburg described the Supertorquer as pushing the "state of the art" and said flying the technology alongside a highly maneuverable spacecraft expands the mission options available to the company's defence and commercial customers.
A secondary experiment aboard Starburst-1 will measure whether the Supertorquer's magnetic field provides meaningful radiation shielding by deflecting charged particles away from onboard systems. Zenno says laboratory testing has shown promising results; a charged-particle counter will gather in-orbit data during the mission.
Market context
Propellant-free attitude control sits at an early but commercially credible stage of the in-space services value chain. Reaction wheels remain the dominant technology for satellites in low Earth orbit, but their mechanical nature creates single-point failure risk on long-duration missions. For spacecraft targeting medium Earth orbit (MEO) and geostationary orbit (GEO), where radiation and operational longevity are more demanding, a solar-powered superconducting alternative has a clearer commercial case.
Portal Space Systems has raised a reported $75 million in funding since emerging from stealth in 2024, and holds both Small Business Innovation Research (SBIR) and Strategic Funding Increase (STRATFI) awards from US defence agencies, signalling substantive government interest in highly maneuverable spacecraft. The dual defence-commercial customer base positions Starburst-1 as both a product demonstration and a government contract qualifier.
Zenno has not disclosed the value of its supply agreement with Portal, the number of units in its production pipeline, or any external fundraising. For investors tracking the in-space services sector, the key near-term milestones are the launch date confirmation, successful on-orbit commissioning of the Supertorquer, and quantified results from the radiation-shielding experiment. A positive in-orbit data set would strengthen the case for the technology becoming standard equipment on maneuverable spacecraft platforms built for the next generation of orbital operations.