Hop Aero's Rook is designed to launch from a 40-foot shipping container, fly through space, re-enter at hypersonic speed and land 250 kg of cargo up to 750 km away in about 15 minutes, on unprepared ground. Matija previously co-founded porkchop at KTH in Stockholm. Its nanosatellite propulsion hardware launched on SpaceX Transporter-3 on 13 January 2022, integrated into a Laika satellite. Hop Aero (YC S26) came out of stealth in July 2026. In September 2025 the Air Force Research Laboratory awarded it a $1.25M Phase II SBIR for Rapid Operations Over Kilometers. It designs in Orange, California and tests at Infinity One Spaceport in Oklahoma.
Matija Milenovic is co-founder and CEO of Hop Aero, which is building container-launched cargo rockets. He previously co-founded porkchop at KTH in Stockholm, whose nanosatellite propulsion hardware launched on SpaceX Transporter-3.
An Orange, California company in Y Combinator's Summer 2026 batch, building Rook, an autonomous rocket designed to launch from a standard 40-foot shipping container and land 250 kg of cargo up to 750 km away in about 15 minutes, on unprepared ground.
The spacetech startup Matija co-founded in 2019 with Victor Gonzales at KTH. It built a fully integrated propulsion system for nanosatellites. The hardware launched on SpaceX Transporter-3 on 13 January 2022, integrated into a Laika satellite.
In September 2025 the Air Force Research Laboratory awarded Hop Aero a $1.25M Phase II SBIR for Rapid Operations Over Kilometers. The award runs through October 2026.
Jacob Balaj is Hop Aero's co-founder and CTO, a Marine Corps veteran who was on SpaceX's booster refurbishment program and led engineering work at Virgin Orbit and Masten.
