Colorado-based Sierra Space has successfully completed a test campaign of its new liquid oxygen and liquid hydrogen-fuelled upper stage engine at a US Air Force Base in California.
Research Laboratory (AFRL) was aimed at continuing to mature upper stage engines to fulfil future National Security Space Launch (NSSL) missions.
NSSL missions are intended to assure the US Department of Defence (DOD) access to space. The US Air Force has been in the process of selecting its next generation NSSL vehicles since 2018.
... to continue reading you must be subscribed
