After 7 months of excitement, hurdles, and wait, SpaceX finally launched Starship for the 2nd time. Although both Super Heavy Booster 9 and Starship 25 exploded in the Earth’s atmosphere, SpaceX achieved the prime objectives of this test.
As Elon Musk and the SpaceX team repeated multiple times, reaching stage separation would be enough to satisfy the objective of this launch. SpaceX accomplished this goal with the Starship flight test #2.
Both 1st stage (Super Heavy rocket booster) and the 2nd stage (Starship spaceship) successfully separated at around T+ 2 mins 50 seconds into the flight and at an altitude of 75 KM.
Flight #1 of Starship did successfully lift off the launch pad, but it did not reach the stage separation phase and had to be detonated in mid-air.
Today’s Starship flight #2 reached stage separation and Booster 9 successfully detached but within seconds of the separation, it was not able to maintain its planned trajectory back to Earth. SpaceX triggered the flight termination system (FTS) on the Super Heavy booster to force a RUD (rapid unscheduled disassembly). SpaceX originally planned for a Booster 9 splashdown in the Gulf of Mexico if the rocket was able to reach back to Earth.
Hot Stage Ring and Stage Separation
SpaceX learned from its mistakes from the 1st Starship launch. The data and experience gained from the 1st flight gave birth to the Hot Stage Ring. In short, this ring was built as an interstage component to be installed between Starship and the Super Heavy booster to help ease the stage separation process.
The Hot Stage Ring that sits between the 1st and 2nd stages of Starship is intended to protect the 1st stage from the 2nd stage Starship engine fire and heat during the stage separation phase.
The following labeled image of the fully integrated Starship shows where the hot stage is placed between the Starship and Super Heavy booster.
As we can see in Diagram 2 above, the Starship Hot Stage Ring is made up of 3 major components, a blast shield, a vented interstage wall (the outer ring), and ship attachment points that connect the 2nd stage above it.
According to SpaceX, adding the Hot Staging Ring will also help increase Starship’s payload to orbit capacity by up to 10%. “Hot staging also helps us maximize the vehicle’s performance by leaving those three 1st stage engines ON, so gravity cannot rob us precious velocity or at least not as much of it,” a SpaceX engineer explained during the live stream of the launch event.
The addition of the hot stage ring did help SpaceX with the smoother stage separation of Starship. However, after detaching from the 2nd stage, the Super Heavy booster did not last for long and met its fate with a RUD (rapid unscheduled disassembly).
SpaceX shared the spectacular moment of the Starship stage separation in a tweet video on X (Twitter).
Starship Lost in Space
After successful stage separation, the Starship continued its normal trajectory towards the orbit. Unexpectedly, Starship kept moving ahead until the communications signals were lost.
For the next few minutes, even SpaceX had no clue where Starship had gone because it went invisible from ground cameras. SpaceX attempted to capture Starship’s launch footage using its Starlink satellites but unfortunately, this also did not work.
After a few minutes, SpaceX engineers from the Mission Control Center in Hawthorne, California confirmed that Starship had also ended in a RUD. The onboard auto flight termination system (FTS) had triggered and it was lost in space.
SpaceX lost communications with the 2nd stage Starship at an altitude of 148 KM. Starship had to fly around 150 – 250 KM and re-enter the Earth’s atmosphere. Sadly, we were not able to witness the re-entry of Starship and SpaceX might have lost all the data that would help in improving Starship’s thermal protection system (TPS).
Starship 25 had 18,000 TPS heat shield tiles installed on it to protect it from the re-entry burn where temperatures can reach up to 1500℃ (2732℉).
We have lost Starship 25 today but SpaceX is getting Starship 28 ready for the next orbital flight attempt. Stay tuned for future updates.
SpaceX CEO Elon Musk, his brother Kimball Musk, and his friend and the CTO of Oracle Larry Ellison were present at the Starship Command Center in Boca Chica, Texas to witness the flight test first-hand.