Portal Space Systems' ultra-mobile Supernova satellite bus could propel transfers from low Earth orbit to geostationary orbit in a matter of hours. The 500 kg vehicle is designed to be payload agnostic and survive in orbit for at least five years while being continuously maneuvered. It uses a solar-thermal propulsion system that produces a delta-V of 6 kilometers per second. Portal aims to conduct an in-flight demonstration in late 2025 or early 2026. It is looking to scale up its team and grow manufacturing to support the production of multiple spacecraft per year.