TechnologyARMY on Instagram: "This test captures Rocket 4’s first-stage engine delivering a full-power hot fire, pushing the system under launch-ready conditions. Engineers are verifying thrust output, combustion stability, and cooling performance during sustained burn — the exact stresses the engine will face during liftoff. Rocket 4 represents Astra’s push for higher reliability and stronger lift capability after earlier mission setbacks. The upgraded engine delivers more thrust, improved effi