SpaceX spacecraft explosion explained by Elon Musk


Shortly after a briefing after the SpaceX astronaut’s flawless launch, CEO Elon Musk released the best explanation for why a prototype spacecraft exploded violently during tests on May 29.

This Saturday, SpaceX successfully completed the fifth static fire of a Raptor engine installed on a prototype large-scale spacecraft, preceded by about an hour and a half of vehicle checks and loading of propellant. Unfortunately, about a minute after Raptor’s shutdown, what was quickly identified as liquid methane began to spurt out of a specific section at the base of Starship, quickly creating a massive cloud as the cryogenic booster boiled and transformed. in gas. The specific source is not clear, but moments later something under Starship SN4 provided the shock or spark necessary to ignite the increasing risk of fire, producing a spectacularly large and violent explosion.

Unsurprisingly, the accidental explosion of fuel and air that was created wiped out the SN4 spacecraft in the blink of an eye, shredding its lower tank (liquid oxygen) into steel confetti and immediately violating the upper tank (methane liquid), which fell to the ground and subsequently exploded again. The Starship spacecraft launch was also staged damaged beyond repair and has been fully dismantled and scrapped within two days of the anomaly. Fortunately, however, SpaceX already has replacement carriers and ships on track to carry the Starship SN4 torch forward and Elon Musk already seems to understand what caused the prototype to disappear.

Shortly after a post-launch briefing celebrating and discussing the SpaceX astronaut’s inaugural launch on May 30, Reuters reporter Joey Roulette could ask Musk on the spectacular disappearance of Starship SN4 the day before. The CEO of SpaceX was quoted as saying that “what we thought was a minor test of a quick disconnect ended up being a big problem”, confirming the suspicions based on a careful analysis of public opinions on the explosion caused by problems with Starship. ground support equipment (GSE).

Starhopper’s quick disconnect umbilical panel is pictured here in May 2019. The Starship SN4 used a similar mechanism, although the plumbing is now located inside the circumference of the vehicle. (NASASpaceflight – bocachicagal)

In Musk’s statement, “quick disconnect” (QD) refers to an umbilical port that connects a launcher to GSE, allowing loading and unloading of propellant and fluids, securing the rocket and providing a telemetry and wired communication link for ground controllers. QDs must perform all of these tasks while being able to break free and disconnect quickly, allowing the rocket to take off while protecting its sensitive ports for easy reuse.

In theory, Starship’s quick-disconnect umbilical panel is even more complex, as it will simultaneously allow the ship to be powered and controlled while seated on a Super Heavy booster and allow docking and refueling in orbit. Since the spacecraft are currently being independently tested on Spartan launch pads, it is unclear whether the current generation of prototypes has been fitted with advanced QD panels. More likely, Musk was referring to a test of a less advanced QD panel similar to the raw version used on Starhopper last year, and SpaceX simply wanted to test its ability to log out and back in to Starship on command.

SpaceX’s existing Starship launch mount was heavily damaged by the SN4 explosion and has since been completely disassembled. (NASASpaceflight – bocachicagal)
The remains of the Starship SN4 have already been erased from the pad. (NASASpaceflight – bocachicagal)

If this is the case, the most likely explanation for the SN4 explosion is that this quick disconnection could not reconnect completely after the test, which resulted in a leak of the liquid methane port when SpaceX started. to fill the rocket. Instead of the highly pressurized fluid returning gently to the ground storage tanks, the liquid methane has been sprayed wildly, similar to the effect one would experience when trying to block an active water source with an open palm.

Work on a second launch mount was already underway when the Starship SN4 exploded on May 29. (NASASpaceflight – bocachicagal)
Starship SN5 and SN6 are simultaneously assembled in SpaceX’s new Vertical Assembly Building (VAB). (NASASpaceflight – bocachicagal)

Compared to the many possible ways in which a powered spacecraft could fail, a propellant leak triggered by a defective umbilical panel is about as practical as possible. The SN4 spacecraft may have been violently destroyed, turning a relatively small error into an exceptionally painful lesson, but SpaceX has already managed to build large-scale prototypes at an almost unbelievably low cost – probably less than $ 10 million each. . The SN5 spacecraft just seems ready to take the place of SN4 on the launch mount, although SpaceX will must build a brand new launch mount before they can resume testing.

At the same time, Starship SN5’s successor – SN6 – is only at a stacking event to reach a level of completion similar to SN4 and SN5. All told, the disappearance of Starship SN4 is just another part of the process of developing a new type of rocket by building and testing equipment – failure can be a valuable tool when managed properly. Based on past observations, SpaceX may be ready to continue testing (and hopefully flying) prototypes of Starship before the end of the month.

Consult Teslarati newsletters for quick updates, field insights and unique insights into the SpaceX rocket launch and recovery processes.


Please enter your comment!
Please enter your name here