SpaceX’s Starship and Super Heavy rocket, which aims to take humans to the Moon and Mars, suffered a fiery end during its second flight last year. Now, SpaceX CEO Elon Musk has revealed the reason behind the explosion and what the company is doing to prevent it from happening again.
On December 9, 2023, SpaceX launched its Starship SN8 prototype from its Boca Chica facility in Texas. The rocket soared to an altitude of about 12.5 kilometers, performed a belly flop maneuver, and attempted to land back on the launch pad. However, the rocket came down too fast and exploded in a spectacular fireball.
Despite the failure to land, SpaceX and Musk considered the flight a success, as it demonstrated many of the capabilities and technologies needed for the Starship and Super Heavy system. The rocket was able to control its attitude and orientation using its four flaps, and it successfully relit its three Raptor engines for the landing burn.
However, the landing burn was not enough to slow down the rocket, and it hit the ground at a speed of about 200 kilometers per hour. The impact caused the rocket to rupture and ignite the remaining propellant, resulting in a massive explosion that destroyed the vehicle and damaged the launch pad.
Musk’s explanation: venting liquid oxygen was the culprit
During a company update posted on X (formerly Twitter) by SpaceX on January 15, 2024, Musk spent an hour telling the faithful about the company’s achievements and his dreams of interplanetary spaceflight. He also provided an update on what happened on the most recent flight.
He said: “If it had had a payload, it would have made it to orbit. Because the reason it didn’t quite make it to orbit was we vented the liquid oxygen, and the liquid oxygen ultimately led to fire and an explosion … we normally wouldn’t have had that liquid oxygen if we’d had a payload so, ironically, if it had had a payload it would have reached orbit.”
Musk did not explain how the venting caused the fire, only that things would have gone differently had there been a payload. Presumably because the liquid oxygen would have been consumed by the Raptor engines.
Venting is a common practice in rocket launches, as it allows the excess pressure and boil-off gas to escape from the tanks. However, venting liquid oxygen, which is extremely cold and reactive, could pose a risk of ignition if it comes into contact with a hot surface or a spark.
SpaceX’s next steps: learning from mistakes and improving the design
Musk said that the next launch could happen as soon as next month, although it depends on the Federal Aviation Administration issuing a license. He said that he reckoned there was a good chance of getting to orbit this time around, and listed a set of impressive goals for flight three.
As well as getting the rocket to orbit without exploding, SpaceX intends to demonstrate an in-space engine burn and prove that it can also de-orbit the rocket. It also wants to test transferring propellant between tanks – an essential milestone for SpaceX’s role in NASA’s Artemis program – and demonstrate the “Pez dispenser” payload door planned for full-sized Starlink satellites.
NASA recently confirmed that the Artemis program was slipping, with the first crewed landing now set for September 2026. Despite Musk’s desire to reduce the gap between Starship launches and accelerate the cadence, SpaceX could certainly use the extra time.
SpaceX’s Starship and Super Heavy rocket is one of the most ambitious and complex projects in the history of space exploration. It aims to create a fully reusable launch system that can carry up to 100 tons of payload to low Earth orbit, the Moon, Mars, and beyond. The rocket consists of two stages: the Starship, which is the upper stage and the spacecraft, and the Super Heavy, which is the booster stage.
SpaceX has been developing and testing various prototypes of the Starship at its Boca Chica site, with the ultimate goal of achieving orbital flight and landing. The company has also been awarded contracts by NASA to use the Starship as a lunar lander for the Artemis program, and by the US Air Force to launch national security payloads.
SpaceX hopes to achieve its first orbital flight with the Starship and Super Heavy this year, and to send the first crewed mission to the Moon by 2025. Musk has also said that he wants to send the first humans to Mars by 2026, and to establish a permanent settlement on the Red Planet by 2030.
SpaceX’s Starship and Super Heavy rocket is a game-changer for the future of space exploration and colonization. However, it also faces many technical and regulatory challenges, as well as competition from other players in the industry. Whether SpaceX can achieve its bold vision remains to be seen, but one thing is certain: the journey will be full of excitement and surprises.