Rockoon
B2Space
B2Space's Rockoon is a stratospheric balloon-assisted small satellite launch system that lifts a rocket to ~35 km altitude before ignition, cutting propellant needs and cost versus conventional ground launch.
Technical specifications
- Launch concept
- Rockoon (stratospheric balloon + rocket)
- Balloon release/launch altitude
- ~35 km
- Payload capacity
- Up to 200 kg
- Target orbit
- Low Earth Orbit, flexible orbit selection
- Propellant reduction
- Up to ~70% less propellant vs. conventional launchers
- Aerodynamic drag loss reduction
- More than 95% reduction
- Launch site flexibility
- Mobile/flexible launch locations, including sea launch
- Flight status (mid-2026)
- Pre-orbital; stratospheric balloon test completed at La Gomera, Canary Islands, Nov 2025; earlier tests include Colibri system balloon test (2021) and Leon zero-pressure balloon launch (2023); no orbital launch yet
About
Rockoon (rocket + balloon) is B2Space’s flagship launch concept, developed over roughly nine years by the company to provide flexible, reliable and low-cost access to Low Earth Orbit for small and micro satellites. A stratospheric balloon carries the launch vehicle to approximately 35 km altitude, above 99.9% of the atmosphere, before the rocket ignites and continues toward orbit. Launching from this altitude reduces aerodynamic drag losses by more than 95%, allows lighter vehicle structures, and is claimed to cut propellant consumption by up to 70% and overall launch costs by up to 80% relative to traditional first-stage rockets. The system is designed to support flexible launch sites, including sea launch, and flexible orbit selection within LEO, targeting small satellite operators who need low-cost, responsive access to space. As of mid-2026, B2Space has not yet flown an orbital Rockoon mission; the program is in a progressive flight-test phase. Key milestones include a Colibri system balloon test (2021), stratospheric zero-pressure balloon launches from Leon (2023), and a stratospheric balloon test from La Gomera, Canary Islands in November 2025 that validated flight procedures and subsystems.
Documentation
No public datasheet yet — request the datasheet / ICD from the supplier.