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The Glass Half-Full Starship Test

Starship Super Heavy,SpaceX,Moon
Mihir Tripathy
Erik Kuna
Jenny Hautmann
April 25, 20238:00 PM UTC (UTC +0)

SpaceX has taken a significant step in the development of its rapidly-reusable launch vehicle, Starship Super Heavy, by flying the beast to an altitude of 39km during its heart-stopping first fight. Did SpaceX fail to complete its larger objectives? Yes. Did they accelerate the program by testing systems and gathering flight data? Also, Yes.

The rocket cleared the pad and climbed as it continued to lose multiple engines and subsystems essential for the ascent. As more and more engines failed, Starship Super Heavy deviated from its planned trajectory before being stopped by the flight termination system over the Gulf of Mexico. Just before the massive vehicle self-destructed for safety about 4 minutes into the flight, SpaceX’s livestream explained that Starship’s visible cartwheels in the sky instead of the planned booster separation, “does not appear to be a nominal situation.”

Despite the explosion, the outcome is a step in the right direction for SpaceX, proving many concepts and producing data about what didn’t go the way they planned. Given the complexity of the rocket, SpaceX had subliminal expectations. With over 3,600 tons of super chilled and densified liquid oxygen and liquid methane loaded on the rocket, one of the major objectives was to lift off and steer away from the launch pad.

“Just don't blow up the launchpad,” said Elon Musk during a Twitter space. At first, it seemed that hurdle might have been cleared but when the dust settled at Starbase, the aftermath was not ideal. And while assessments by the company and local officials still need to be completed, the damage to the launch facility seems significant. This has been SpaceX's modus operandi since they first stuck a shovel in the dirt road that is now Starbase: Build, test, destroy, then build it better. Before this test, SpaceX had only flown (and destroyed) Starship prototypes without its giant booster.

Shot taken via remote pad camera placed by Erik Kuna

Since its unveiling in 2016 at the International Astronomical Congress in Guadalajara, Mexico, Starship has undergone significant design changes, including transitioning from carbon fiber to stainless steel and abandoning landing legs in favor of using chopsticks on the launch pad to catch the booster and the ship.

Standing 120 meters (394 feet) tall, Starship Super Heavy is the largest and the most powerful launch system in the world, capable of launching substantial payloads to any destination in the solar system, allowing humans to live and work on Mars and conduct speedy intercontinental point-to-point transportation to destination across Earth’s surface. NASA needs Starship to bring humans down to the lunar surface during the Artemis III mission.

The highly anticipated first integrated launch of Starship and its Super Heavy booster had been looming ever since the successful 31-engine static fire of Booster 7 on February 9. Although the test was originally intended to fire all 33 engines, one engine was disabled pre-firing and another engine aborted just before ignition. Despite the monumental and high-risk nature of the test, SpaceX demonstrated the booster's technical readiness to successfully fire a large cluster of engines and proved that the launch pad can withstand 50% of the engines’ thrust.  On Monday, April 17, the first launch window was unceremoniously scrubbed due to a frozen valve issue and turned into a wet dress rehearsal. Teams worked through the next couple of days to get ready for Elon’s wish: a 4/20 launch.

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As the sun came up on the infamous weed holiday, the visibility was extremely poor, with a thick blanket of fog obscuring the rocket from view. Despite the less-than-ideal viewing conditions for onlookers near the launch site, it wasn’t affecting the launch commit criteria and SpaceX pressed on with the second attempt, keeping a close eye on pesky upper-level winds.

Just like the previous attempt, the countdown and the propellant load went smoothly. 

The vents on the rocket periodically released oxygen and methane as they boiled off. At T- 40 seconds before the launch, the flight director called a hold due to slightly off-nominal flight pressures on the B7. A few seconds later, the countdown resumed for the historic flight.

Just 8 seconds before T-0, 30 out of 33 Raptors that power Super Heavy successfully ignited and the full stack lifted off and cleared the pad. It began its pitch maneuver towards the Gulf of Mexico. becoming the largest and most powerful rocket ever developed to take flight, surpassing NASA's Space Launch System launched last year. At around T+ 30 seconds, Booster 7 lost a Raptor engine, followed by one of its Hydraulic Power Units.

Quick View: Starship Prototype


50m / 164ft


9m / 29.5ft

Propellant Capacity

1,200t / 2.6Mlb


1,500tf / 3.3Mlbf

Payload Capacity


Starship continued to make its way to Max-Q, the point of maximum aerodynamic stress experienced by the rocket, losing more engines along the way. Down an HPU and over 8 Raptors, Starship continued along its planned trajectory, demonstrating a strong engine-out capability. 

Engines continued to fail and the vehicle was unable to maintain the correct trajectory. As Starship reached the point of main-engine cut-off and stage separation, not only did the booster separation system fail, meaning the Starship was still attached to Superheavy, the whole stack started tumbling. More and more engines failed and many of them started burning the copper inside the engine, characterized by green flames. 

A couple of tumbles later as the rocket moved out of the launch safety corridor, the flight termination system was activated on both the ship and the booster as the rocket underwent “Rapid Unscheduled Disassembly”. It blew itself up.

Onlookers view the liftoff of Starship Super Heavy captured by Erik Kuna

As SpaceX works towards a second test flight, it'll involve more than just implementing changes on the Starship Super Heavy system. The orbital launch site will require hefty repairs, including re-concreting the surface and refurbishing the launch tower, chopsticks, and tank farm.

While Starship did clear the launch pad, the facility suffered the wrath of 30 Raptor engines igniting at 90% thrust levels. Initially ramping up to 50%, the engines throttled up to the operational levels which shattered the concrete base of the orbital launch mount, according to SpaceX’s early analysis.

Despite using the Fondag concrete – specifically designed to withstand extreme forces and temperatures in the harshest environments – the high-energy engine plume blew away the concrete debris, exposing the hexagonal foundation of the launch mount. This flying debris inflicted damage upon the tank farm as well as the surrounding area, including the Starhopper. 

A massive water-cooled steel plate is also in the works and will be installed under the launch mount to sustain the engine plume of the 33 Raptor engines. Elon clarified on Twitter it wasn’t ready in time for the first launch and based on the data from the static fire, teams didn’t expect this level of damage. “[The steel plate] Wasn’t ready in time & we wrongly thought, based on static fire data, that Fondag would make it through 1 launch.”

SpaceX may have expected significant damage to the launch pad without these protection systems but made the decision to launch anyway because the data and lessons learned with this particular Starship Super Heavy and the ground support equipment were more valuable than waiting for such systems to be installed and tested. 

Elon anticipates a rather quick return to launch, saying “Looks like we can be ready to launch again in 1 to 2 months.” 

The orbital launch mount after liftoff captured by Jenny Hautmann

SpaceX will be working with the Federal Aviation Administration, and other government bodies to investigate the failure points. The FAA will green-light the second launch only if it approves the company’s investigation report and officially closes it. 

Despite the fiery end to the test, Starship’s historical integrated flight test can hardly be considered a total failure as it provided SpaceX with loads of valuable data that will help direct their design decisions in the future. SpaceX employs an iterative development process for Starship that involves a continuous cycle of design, testing, and refinement, with new prototypes incorporating improvements over the previous iteration. That also means quite a few blown-up prototypes with more expected to meet the same fate in the future.

Starship Super Heavy Booster 7 and Ship 24 were outdated even before they were stacked and readied for this failed test launch as SpaceX had already introduced flight reliability upgrades for future vehicles. The forthcoming Booster 9 will be equipped with electric gimbals for the engines, eliminating the need for HPUs. The 33 outfitted Raptor engines are more reliable and are equipped with enhanced shielding, designed to isolate them from potential engine explosions in flight. With these upgrades, SpaceX aims to prevent the same failures that plagued this flight.

The integrated test flight provided teams with a lot of information about what works and what doesn’t on the Super Heavy booster, however, there’re still a lot of unknowns on the Starship itself, particularly the heat shield. It might take several test flights for SpaceX to achieve orbit and even more flights before they’re able to recover and refly the vehicle with confidence.

Starship has great expectations and even greater ambitions. It remains to be seen if SpaceX will be able to truly lower the cost of access to space and enable frequent crewed flights to the Moon and Mars. What’s clear from this test is that Starship requires a lot of work and it’ll be a substantial number of successful flights before SpaceX will be flying the first crews.

Mihir Tripathy
Erik Kuna
Jenny Hautmann
April 25, 20238:00 PM UTC (UTC +0)