Musk's SpaceX's first Starship launch has already passed, with the Starship exploding and disintegrating at a height of 32 kilometers, with debris falling into the Gulf of Mexico, failing to achieve its intended goal. However, Musk seemed very happy, as did SpaceX employees and the American public, who were all applauding and cheering because their expectations were low. As long as the launch tower wasn't destroyed, any other outcome was acceptable.
So, what exactly went wrong with this Starship launch? I haven't seen a specific analysis of the reasons yet, but I will analyze it based on the information I have seen.
From what we can see, the Starship soared to an altitude of more than 30 kilometers before it started struggling in the air. It eventually reached an altitude of 39 kilometers, but it exploded and disintegrated as it descended to 32 kilometers.
What happened in between?
It turned out that the Starship and the booster could not separate. To avoid causing damage on the ground due to loss of control, ground controllers detonated pre-placed explosives between the methane and liquid oxygen tanks. The explosion caused by the mixture of methane and oxygen sent all debris falling into the Gulf of Mexico.
But why couldn't the Starship and the booster separate? The connection between the first-stage booster and the second-stage Starship, like the Falcon 9, used an aerodynamic separation mechanism, which is different from the explosive bolts used by most rockets.
The fundamental reason is that the lower stage of the Falcon 9 and both stages of the Starship need to be recovered. Using explosive bolts might cause structural damage. Although explosive bolts are the safest and most effective separation method, it's not suitable for recoverable rockets.
Therefore, the Falcon 9 uses an all-aerodynamic stage separation system to achieve low-impact, highly reliable separation, which can be tested on the ground. This is an aluminum structure reinforced with carbon composite material, equipped with grid fins and reaction control thrusters for redirecting and guiding the booster back to Earth.
At the top of the Falcon 9 booster, there is a helium-driven aerodynamic pushrod. The locking mechanism of the aerodynamic stage separation system is also helium-driven. When it unlocks, the aerodynamic pushrod will start and push the upper stage away. The Starship's aerodynamic separation system might be similar, but there's not much information. What I've seen is that it's like the Falcon 9 upper stage releasing Starlink satellites, using the centrifugal force of rocket rotation to release the satellites.
It seems that the Starship and the Falcon 9 are just the opposite; the aerodynamic separation system is installed on the upper stage, which is at the bottom of the Starship. It seems to lack an aerodynamic pushrod because Musk felt that even that could be eliminated. When the separation occurs, after unlocking, the engine below the booster that can rotate will apply a small but significant rotation, effectively "popping" the Starship open. Since the booster's fuel has almost burned out by then, the Starship's weight is five times heavier than the booster, so it can stably drift away from the booster in a straight line.
The above is not entirely certain, as there is very little information available. Below is my exclusive analysis: Since the booster's thrust was not fully open during the Starship's first launch, and 5 to 6 Raptor engines were not working - some said that there were eight not working in the final stage - the Starship system may have not been accelerating but decelerating after reaching a height of more than 30 kilometers. At this point, the pressure of the Starship on the booster would increase - the booster is still pushing, but the overall system's speed has slowed down. This is like pushing a car uphill; a car that feels light on level ground will suddenly exert much more pressure on you.
As a result, the pressure on the locking mechanism increases, possibly becoming too tight or even damaged, preventing it from unlocking. Meanwhile, the booster's rocket is still rotating, resulting in the struggling Starship we saw in the air, eventually leading to the detonation.
It is said that the Starship's locking mechanism has been tested on the ground thousands of times and can unlock very stably, but no one may have anticipated the situation encountered during the first launch. As a result, the upper and lower stages could not separate - Musk may have been genuinely careless!
If the Starship had managed to separate in time, even with insufficient speed, it might still have had a chance to enter space with its own propulsion.