Hop Aero

Hop Aero is a Y Combinator-backed (S26) aerospace startup building Rook, an autonomous hypersonic cargo rocket that launches from a standard shipping container and lands up to 250 kg of cargo on unprepared ground as far as 750 km away in about 15 minutes, targeting contested military logistics and high-downtime commercial supply chains. Founded in 2024 by Matija Milenovic (CEO) and Jacob Balaj (CTO), the company won a $1.25M Direct-to-Phase-II SBIR from the Air Force Research Laboratory in September 2025 and has completed an engine hot-fire test and a tethered flight of a small-scale prototype.

Company Facts

  • Headquarters: Orange, United States
  • Founded: 2024
  • Employees: 6
  • Type: startup
  • Website: https://hop-aero.com
  • Industries: Aerospace, Defense, Logistics, Space Technology

Key People at Hop Aero

  • Tyson Butterfield — Founding Systems Engineer, Hop Aero
  • Matija Milenovic — Co-Founder & CEO, Hop Aero
  • Jacob Balaj — Co-Founder & CTO, Hop Aero
  • Elizabeth Nava — Business Operations, Hop Aero
  • Devin James Rivera Ho — Aerospace Engineer, Hop Aero

Investors & Owners

  • Y Combinator, LLC

Recent Transactions

  • Hop Aero Pre-Seed Round