Starship flight test 1 was the maiden flight of the integrated SpaceX Starship launch vehicle. SpaceX performed the flight test on April 20, 2023. The prototype vehicle was destroyed less than four minutes after lifting off from the SpaceX Starbase in Boca Chica, Texas. The vehicle temporarily became the most powerful rocket ever flown, breaking the half-century-old record held by the Soviet Union's N1 rocket. The launch was the first "integrated flight test," meaning it was the first time that the Super Heavy booster and the Starship spacecraft flew together as a fully integrated Starship launch vehicle.
The launch was part of SpaceX's Starship development program, which follows an iterative and incremental approach involving frequent, and often destructive, test flights of prototype vehicles. Before the launch, SpaceX officials said they would measure the mission's success "by how much we can learn" and that various planned mission events "are not required for a successful test". The flight was generally regarded as having furthered Starship's development, and a variety of public officials congratulated SpaceX, including NASA administrator Bill Nelson and European Space Agency Director General Josef Aschbacher.
It was planned for the Starship spacecraft to complete nearly one orbit around the Earth before reentering the atmosphere, performing a controlled descent and splashing down in the Pacific Ocean near Hawaii. The Super Heavy booster was to have performed a similar landing in the Gulf of Mexico, about off the Texas coast about 8 minutes after liftoff.
The rocket lifted off at 13:33 UTC (8:33am CDT, local time at the launch site) from SpaceX's private launch site near Boca Chica, Texas. The liftoff damaged the launch pad and its surrounding infrastructure, which SpaceX said was unexpected. Some debris spread into Boca Chica State Park. Three engines did not start or aborted before liftoff, and several others failed during the flight. The vehicle passed max q and entered supersonic flight, but, due to a lack of thrust or thrust vector control, no attempt was made at stage separation. After Starship began to lose altitude and tumble, the autonomous flight termination system (AFTS) on the vehicle activated, which took 40 seconds to destroy the vehicle, nearly 4 minutes into the flight.
After the test, the Federal Aviation Administration (FAA) grounded the launch program pending results of a standard “mishap investigation” overseen by the agency and performed by SpaceX. The FAA said that a return to flight would depend on the agency's determination that future launches would not affect public safety. In August 2023, SpaceX submitted to the FAA the 63 "corrective actions" that it would need to take before another Starship launch would be allowed. Dust scattered by the launch initially caused some health concerns, but was later found by a laboratory to be ordinary beach sand, not posing a health hazard.
A second flight test of the Starship vehicle occurred on November 18, 2023, seven months after its maiden flight. The launch did not repeat issues encountered on the first flight; the vehicle successfully performed stage separation using a new method, but both vehicles were lost thereafter.
Background Starship
Developed by SpaceX, Starship is a super heavy-lift launch vehicle, the largest and most powerful ever developed. Standing tall, it is projected to be able to carry of payload in a fully reusable configuration. Its 33 first-stage Raptor engines nominally generate more than of thrust. This is roughly twice that of NASA's Saturn V () which flew between 1967 and 1973; more than NASA's SLS, which produced of thrust at liftoff in 2022; and well above the of thrust from the 30 engines that powered the Soviet Union's N1 rocket between 1969 and 1972.
On its first test flight, Starship broke the N1's half-century-old record for the most powerful rocket-stage ever launched.
Both of Starship's stages are designed to perform controlled landings at the launch site enabling them to fly multiple times. SpaceX plans to use the launch vehicle for launching satellites, space tourism, and interplanetary spaceflight.
Development
Starting in 2019, SpaceX built several prototypes for the upper stage and launched them a total of nine times, culminating with the launch of Starship SN15 on May 5, 2021, that completed a successful high-altitude flight test of six minutes. SpaceX continued to build new upper stages, completed several first stages, and performed ground tests while waiting for governmental launch clearances.
In 2021, SpaceX filed an application with the Federal Communications Commission in which it described the planned first flight test of the Starship-Super Heavy booster stack. The application said that, after liftoff from Starbase, the booster would separate and land about offshore while Starship would continue flying east and land about off the Hawaiian island of Kauai.
In June 2022, the environmental review of the launch site concluded with a "mitigated FONSI" (Finding of No Significant Impact) ruling, requiring the company to implement various mitigations to local wildlife and historical sites but otherwise permitting a launch license to be issued.
On February 9, 2023, SpaceX performed a final static fire of the Super Heavy booster. A flight readiness review was completed on April 8, 2023. An April 11 launch rehearsal was canceled. The Federal Aviation Administration (FAA) issued an orbital launch license for the vehicle on April 14, 2023.
Opinions before launch Before the launch, 27 organizations including the Sierra Club, South Texas Environmental Justice Network, Another Gulf is Possible, Voces Unidas, and the Carrizo/Comecrudo Tribe signed a letter expressing their concerns and opposition to it. They cited gentrification and overpolicing of the area, wildlife habitat and native ceremony disruption, and risk of methane-emitting accidents, among others.
Test objectives SpaceX said it would measure the mission's success "by how much [SpaceX] can learn" and that completion of mission milestones were "not required for a successful test". Before the April 20 launch, SpaceX CEO Elon Musk estimated a 50% chance for a successful test, saying that if the rocket gets "far enough away from the launchpad before something goes wrong, then I think I would consider that to be a success. Just don't blow up the launchpad."
Launch
Flight profile The spacecraft flight plan was to lift off from SpaceX's Starbase facility along the south Texas coast, then conduct a powered flight until reaching the desired transatmospheric Earth orbit, estimated to be around , which would have caused Starship to re-enter the atmosphere after roughly 1 hour, 17 minutes of flight, nearly completing a full orbit.
Though both of Starship's rocket stages are eventually intended to be reusable, SpaceX planned to discard both stages at the end of this flight.
The test flight consisted of prototype vehicles Ship 24 and Booster 7. Both the booster and the spacecraft would have performed controlled touchdowns on the ocean surface. According to filings with the FCC, the booster would have performed a boostback burn and sought to splash down about offshore in the Gulf of Mexico, while the Starship spacecraft would have splashed down in the Pacific Ocean about northwest of Kauai.
Flight timeline TimeEventApril 17, 2023April 20, 2023−02:00:00 Flight director conducts a poll and verifies go for propellant loading−01:39:00Super Heavy propellant (liquid oxygen and liquid methane) load start−01:22:00Starship fuel (liquid methane) load start−01:17:00Starship oxidizer (liquid oxygen) load start−00:16:40 Super Heavy engine chill−00:00:40Fluid interfaces begin the venting sequenceResumed after hold−00:00:08 Super Heavy ignition sequence begins −00:00:06 Super Heavy engine ignition Ignition of three engines was terminated because the flight software did not deem them "healthy enough"+00:00:05Liftoff Successful liftoff, but significantly damaged launch pad +00:00:55Throttle down for max q during ascent (moment of peak mechanical stress on the rocket) Later and lower max q than planned +00:02:49 Super Heavy most engines cutoff (MECO) Fires in the aft end of the booster led to a loss of communication between the primary flight computer and a majority of the engines +00:02:52Stage separation Vehicle lost control and began spinning. FTS was triggered at T+3:10 and the stack was destroyed at T+4:01 +00:02:57Starship ignition +00:03:11 Super Heavy boostback burn startup +00:04:06 Super Heavy boostback burn shutdown +00:07:32 Super Heavy is transonic +00:07:40 Super Heavy landing burn startup +00:08:03 Super Heavy splashdown +00:09:20Starship engine cutoff (SECO) +01:17:21Starship atmospheric re-entry interface +01:28:43Starship is transonic +01:30:00Starship Pacific impact
April 17, 2023, attempt The Starship and Super Heavy stack was loaded with propellant at Starbase and was set to launch at 13:20 UTC (8:20 a.m. CDT). However, the launch was aborted at T−8:05 due to a frozen pressurization valve on Booster 7. Before the abort, SpaceX launch control worked to fix the problem, aiming to proceed with a launch the same day. Due to the valves exhibited low responsiveness, SpaceX changed the scheduled flight to a wet dress rehearsal that ended at T−40 seconds. SpaceX said it would need at least 48 hours to prepare for a second attempt.
April 20, 2023, 2nd attempt
A 62-minute launch window opened at 8:28 a.m. CDT (13:28 UTC) on April 20, 2023. At 08:33 CDT (13:33 UTC), the vehicle successfully lifted off, albeit while causing damage to the launch pad. Starship slid laterally off the launchpad, as three engines failed to ignite upon liftoff.
Multiple Raptor engines failed during flight. At about 27 seconds into the flight, SpaceX lost communications with another engine because of "some kind of energetic event". SpaceX shows a discrepancy in its webcast, between the number of engines seen not working in the live video, and the number of engines shut down in the superimposed graphics.
It has been suggested that a small explosion visible around T+0:30 was the failure of a hydraulic power unit, but this was not confirmed by SpaceX.
Eighty-five seconds into the launch, SpaceX lost thrust vector control of the 13 central engines and thus the ability to steer the rocket. The vehicle rose to about before losing altitude and entering a loop, after which its AFTS (autonomous flight termination system) was activated. The AFTS was intended to immediately destroy the vehicle, however, the booster's engines continued to fire until 40 seconds after the AFTS was triggered, about four minutes into the flight at a height of . No injuries or public property damage were reported by the Federal Aviation Administration.
Aftermath
Technical assessments The launch was generally regarded as an important step in Starship's iterative and incremental developmental progress. A variety of public officials and figures congratulated SpaceX on the outcome of the test flight, including NASA administrator Bill Nelson, European Space Agency Director General Josef Aschbacher, retired Canadian astronaut Chris Hadfield, and executive director of the American Institute of Aeronautics and Astronautics (AIAA) Dan Dumbacher.