SpaceX's Starship is designed to fundamentally alter humanity’s access to space, ultimately enabling us to make life multiplanetary. The third flight test of Starship and Super Heavy made tremendous strides towards this future and was an important step on the road to rapidly reliable reusable rockets.
On March 14, 2024, Starship successfully lifted off at 8:25 a.m. CT from Starbase, Texas. All 33 Raptor engines on the Super Heavy Booster started up successfully and completed a full-duration burn during ascent, followed by a successful hot-stage separation. This was the second successful ascent of the Super Heavy booster, the world’s most powerful launch vehicle. At stage separation, Starship's six second stage Raptor engines all started successfully and powered the vehicle to its expected trajectory, becoming the first Starship to complete its full-duration ascent burn.
Following stage separation, Super Heavy initiated its boost back burn, which sends commands to 13 of the vehicle’s 33 Raptor engines to propel the rocket toward its intended landing location. All 13 engines ran successfully until six engines began shutting down, triggering a benign early boostback shutdown.
The booster then continued to descend until attempting its landing burn, which commands the same 13 engines used during boostback to perform the planned final slowing for the rocket before a soft touchdown in the water, but the six engines that shut down early in the boostback burn were disabled from attempting the landing burn startup, leaving seven engines commanded to start up with two successfully reaching mainstage ignition. The booster had lower than expected landing burn thrust when contact was lost at approximately 462 meters in altitude over the Gulf of Mexico and just under seven minutes into the mission.
The most likely root cause for the early boostback burn shutdown was determined to be continued filter blockage where liquid oxygen is supplied to the engines, leading to a loss of inlet pressure in engine oxygen turbopumps. SpaceX implemented hardware changes ahead of Flight 3 to mitigate this issue, which resulted in the booster progressing to its first-ever landing burn attempt. Super Heavy boosters for Flight 4 and beyond will get additional hardware inside oxygen tanks to further improve propellant filtration capabilities. And utilizing data gathered from Super Heavy’s first-ever landing burn attempt, additional hardware and software changes are being implemented to increase startup reliability of the Raptor engines in landing conditions.
During Starship’s coast phase, the vehicle accomplished several of the flight test’s additional objectives, including the first ever test of its payload door in space. The vehicle also successfully completed a propellant transfer demonstration, moving liquid oxygen from a header tank into the main tank. This test provided valuable data for eventual ship-to-ship propellant transfers that will enable missions like returning astronauts to the Moon under NASA’s Artemis program.
Several minutes after Starship began its coast phase, the vehicle began losing the ability to control its attitude. Starship continued flying its nominal trajectory but given the loss of attitude control, the vehicle automatically triggered a pre-planned command to skip its planned on-orbit relight of a single Raptor engine.
Starship went on to experience its first ever reentry from space, providing valuable data on heating and vehicle control during hypersonic reentry. The lack of attitude control resulted in an off-nominal entry, with the ship seeing much larger than anticipated heating on both protected and unprotected areas. High-definition live views of entry and a considerable amount of telemetry were successfully transmitted in real-time by Starlink terminals operating on Starship. The flight test’s conclusion came when telemetry was lost at approximately 65 kilometers in altitude, roughly 49 minutes into the mission.
The most likely root cause of the unplanned roll was determined to be clogging of the valves responsible for roll control. SpaceX has since added additional roll control thrusters on upcoming Starships to improve attitude control redundancy and upgraded hardware for improved resilience to blockage.
Following the flight test, SpaceX led the investigation efforts with oversight from the FAA and participation from the National Aeronautics and Space Administration (NASA) and the National Transportation and Safety Board (NTSB). During Flight 3, neither vehicle’s automated flight safety system was triggered, and no vehicle debris impacted outside of pre-defined hazard areas. Pending FAA finding of no public safety impact, a license modification for the next flight can be issued without formal closure of the mishap investigation.
Upgrades derived from the flight test will debut on the next launch from Starbase on Flight 4, as we turn our focus from achieving orbit to demonstrating the ability to return and reuse Starship and Super Heavy. The team incorporated numerous hardware and software improvements in addition to operational changes including the jettison of the Super Heavy’s hot-stage adapter following boostback to reduce booster mass for the final phase of flight.
The third flight of Starship provided a glimpse through brilliant plasma of a rapidly reusable future on the horizon. We’re continuing to rapidly develop Starship, putting flight hardware in a flight environment to learn as quickly as possible as we build a fully reusable transportation system designed to carry crew and cargo to Earth orbit, the Moon, Mars, and beyond.
Click here to watch SpaceX Starship's third flight test.
