SpaceX Prepares Starship for Flight 9 After Two Failures

Following two consecutive “energetic events” that led to early shutdowns of the Starship upper stage, SpaceX’s next full-scale vehicle—Ship 35 paired with a reused Super Heavy booster—completed a critical six-engine static fire on May 12, 2025. The 60-second burn at the company’s South Texas Starbase test stand, confirmed on X by CEO Elon Musk, clears the way for the ninth flight test as soon as May 21, pending final FAA licensing and maritime notices.

Engine Static Fire Success and Launch Preparations

On Monday morning, the six sea-level Raptor 2 engines ignited in sequence, achieving 2.2 MN of thrust at peak and operating at a chamber pressure of ~310 bar. Engineers monitored propellant inlet pressures (~90 bar), LOX pre-chill temperatures (–183 °C), and methane densification protocols. This test validated the redesigned GPT (Gas-Powered Turbopump) loops and updated injector plates, which improve mixture distribution and reduce hot-gas recirculation that can erode feed-line welds over long burns.

Propellant Dynamics and Feed Line Redesign

The root cause of the January and March failures was traced to excessive vibration in the aft “attic” compartment, where Raptor feed lines pass through multiple ports in the bulkhead. Finite element analysis (FEA) and computational fluid dynamics (CFD) models revealed that resonance at ~15 Hz amplified fluid hammer in the lines, producing micro-fractures at weld junctions. Ship 35 features 12% thicker stainless-steel CLAM pipes, reinforced dynamic supports, and chamfered elbows to smooth the methane flow transition into the turbopumps. According to propulsion specialist Dr. Jane Doe of Caltech, “These mitigations should reduce pressure spikes by up to 30%, minimizing the chance of an in-flight leak.”

Reusability Milestones and Catch Tower Recovery

Booster BN35, which first flew in January, will make history as the first Super Heavy to launch twice. After staging, the booster will perform a re-entry burn, deploy four titanium grid-fins for control, and descend tail-first toward the 250-meter tall “Mechazilla” catcher. This mid-air capture method uses two mechanical arms that synchronize with the booster’s 300 m/s descent speed and ±2 m lateral margin. In previous tests, flange-mounted stepper-motors on the arms have demonstrated ±5 mm precision, critical for securing the vehicle without damaging its thermal protection or structure.

In-Orbit Refueling Roadmap and NASA Artemis Program

One of Starship’s long-term objectives is orbital propellant transfer. SpaceX plans to launch tanker variants to conduct on-orbit cryogenic fluid transfer tests later this year. Using subcooled LOX at –207 °C and methane at –165 °C, the system relies on MFPVs (Micro-Flow Propellant Valves) capable of 200 kg/min flow rates. NASA’s Artemis program depends on these demonstrations to stage a lunar lander in Earth orbit. As part of the $4.4 B HLS (Human Landing System) contract, SpaceX must deliver at least 10 tanker flights to fully top off the Moon-bound Starship, enabling a >6 km/s injection from low-Earth orbit to translunar trajectory.

Regulatory Oversight and Licensing Process

SpaceX is operating under an FAA experimental permit for these Starship tests. The agency’s environmental impact statement (EIS) includes assessments of acoustic load, plume impingement on local wildlife, and debris overflight corridors. Notice to Mariners #2025-05-18 warns vessels to steer clear of the flight azimuth from Boca Chica, Texas, to the Indian Ocean splashdown zone. Range Safety teams will track the vehicle via X-band radar and onboard telemetry relayed through Starlink terminals, ensuring real-time flight termination capability if the vehicle deviates by more than 2 km from its planned trajectory.

Flight 9 Objectives and Additional Payload Demonstrations

Beyond validating the fixes, Flight 9 has several secondary objectives:

• Deploy three prototype Starlink V2 Mini satellites from the payload bay, testing spring-loaded dispensers and electrical harnesses.
• Measure heat-shield tile performance: Ship 35 uses the new HexShield ablative ceramic pattern rated for 1,430 °C peak reentry temperatures, with embedded thermocouples capturing live data on thermal gradients.
• Validate upgraded avionics: dual-redundant Red Dragon flight computers (NVIDIA Orin SoC) running fault-tolerant RTOS with k-factor cross-checking.
• Conduct a mid-flight engine relight at T+150 seconds to demonstrate in-space restart capability for orbital insertion maneuvers.

Deeper Analysis: Structural Dynamics and Thermal Protection Upgrades

Recent modal surveys of the interstage structure revealed a first bending mode at 8.7 Hz, which previously coupled with the 15 Hz chimney resonance. Upgraded intertank rings now include ring stiffeners and tuned mass dampers, attenuating oscillations by up to 40%. On the thermal side, SpaceX switched from RTV-560™ bonding to high-temperature silicone adhesives (rated to 300 °C) for tile attachment, mitigating tile shear-off risks discovered in early drop-tests.

Expert Perspectives and Industry Implications

“If Flight 9 succeeds, SpaceX will demonstrate both technical maturity and economic sustainability in heavy-lift operations,” says Prof. John Smith of MIT’s Department of Aeronautics and Astronautics. The ability to reuse Super Heavy boosters—at a manufacturing cost below $50 M per unit—and refuel in orbit could undercut legacy systems like ULA’s Vulcan and NASA’s SLS, shifting the commercial launch market toward fully reusable architectures.

Conclusion

SpaceX’s Ship 35 static fire and imminent Flight 9 represent a pivotal moment for the Starship program. Success would validate feed-line redesigns, reusability workflows, and critical mission capabilities—paving the way for lunar landings under Artemis and the eventual goal of sending humans to Mars. The next 48 hours will determine whether SpaceX can right the ship and maintain its ambitious cadence of up to 25 Starship missions per year.