Starship Flight 9 Reaches SECO, but Falls Short on Key Milestones

Engine bay of Ship 35 prior to SECO // Photo: SpaceX Webcast

On May 27, 2025, SpaceX launched its ninth Starship flight test from Starbase, Texas, marking the first reuse of a Super Heavy booster. Booster 14-2, fresh off its inaugural flight in January, powered the 403-foot stack aloft at 6:37 p.m. CDT. The mission aimed to break a two-flight streak of upper-stage failures by carrying Starship Ship 35 to second stage engine cutoff (SECO), deploying eight Starlink mass simulators, relighting a Raptor in orbit, and gathering critical reentry data for future rapid reuse. While the vehicle successfully cleared the dense lower atmosphere and reached SECO, multiple off-nominal issues prevented it from achieving its full suite of objectives.

Booster 14 Performs First Reflight

Booster 14-2 began its second flight by executing a near-textbook ascent burn, including a controlled flip maneuver distinct from previous random orientations. Designed to test a higher angle-of-attack reentry profile for increased atmospheric drag and reduced landing propellant, the booster’s novel flip and boostback sequence proceeded as planned. However, about 6 minutes and 20 seconds into flight—immediately after initiating its landing burn—the booster suffered “rapid unscheduled disassembly” and broke apart over the Gulf of Mexico. “Confirmation that the booster did demise,” said SpaceX communications lead Dan Huot during the live webcast.

Ship 35 Reaches SECO but Falls Short on Deployment and Attitude Control

Starship 35 separated cleanly from the booster and coasted to SECO, successfully entering a suborbital trajectory eastward over the Atlantic. The upper stage then attempted to deploy eight Starlink dummy satellites around T+18.5 minutes, which would have marked a major first for the program. Unfortunately, Ship’s payload door failed to open fully, forcing SpaceX to abandon the deployment attempt

Shortly thereafter, at roughly T+30 minutes, Ship 35 began tumbling. Telemetry indicated a leak in one of its internal propellant tanks—critical sources for the vehicle’s reaction control system—caused a sudden loss of attitude control. The spin prevented an in-orbit relight of one of Ship’s Raptor engines, another planned experiment, and ultimately led to the vehicle’s uncontrolled breakup and burn-up during reentry.

Lessons Learned and Path Forward for Flight 10 and Artemis

Although Ship 35 did not complete all objectives, the flight provided invaluable data on booster reentry aerodynamics, stage-separation dynamics, and hardware performance under off-nominal conditions. SpaceX’s incremental hardware upgrades—ranging from metallic and actively cooled heat-shield tiles to integrated catch-fittings—were tested in a real-world environment, accelerating the feedback loop for design refinements.

Looking ahead, Flight 10 will build directly on these lessons, with Ship 36 and Booster 16 (or potentially Booster 15) prepared to incorporate fixes for the propulsion-system leak and payload-door mechanisms. NASA, which relies on Starship for its Artemis lunar landing architecture, will be watching closely: a fully reusable, rapidly turned-around Starship is essential to meeting the agency’s 2027 crew-landing timeline.

Despite the setbacks, Flight 9 demonstrated the program’s resilience and iterative testing approach, edging Starship incrementally closer to operational status. As SpaceX integrates the telemetry and hardware insights from this flight, the next test promises yet another critical milestone on the road to routine, reusable access to deep space.