Rocket 4
Rocket 4 is an expendable, small-lift launch vehicle under development by Astra Space. Announced in May 2022, it will initially be capable of placing 600kg in Low Earth Orbit.
The first stage will utilize two Astra-built tap-off cycle engines derived from Firefly's Reaver engine and will be fuelled with RP-1/LOX. The second stage will utilize a single Hadley Vacuum engine from Ursa Major and will also be fuelled by RP-1/LOX.
It is designed to be rapidly transportable and deployable to nearly anywhere in the world via Astra's Launch System 2.0 containerized GSE.