Starship SN11 explodes during landing-flip maneuver
Despite zero-visibility fog conditions at the launch site, SpaceX’s Starship SN11 attempted to complete what three previous prototypes could not, launch to 10 kilometers, land and not explode. However, it wasn’t to be.
Liftoff from SpaceX’s launch site in Boca Chica, Texas, took place at 8 a.m. CDT March 30, 2021, making it the earliest launch for all its high-altitude prototypes to date. That came at the price of visibility, however, as the morning fog in the area had yet to burn off, making viewing conditions for those in the area nearly impossible.
That apparently wasn’t a problem for SpaceX, which had countless streams of telemetry coming from Starship SN11.
From what could be seen on various livestreams on the internet, including SpaceX’s official broadcast, liftoff appeared to go as planned, similar to the previous three test flights, with all three Raptor engines firing to begin pushing Starship SN11 toward its planned 10-kilometer hover point. During its climb, two engines were shut down, as planned, until the vehicle reached its target altitude.
It was at this point the final Raptor cut off and the vehicle began its controlled belly flop toward the landing pad.
Just moments before reaching the surface, after the SpaceX webcast narrator had called the passing of flight level of 1 KM, at least one Raptor engine appeared to re-ignite to begin its three-engine landing-flip maneuver, the signature move of SpaceX’s Starship vehicles.
It was at that moment, however, that SpaceX’s live feed cut out. The time showed 5 minutes, 49 seconds into the test.
Spaceflight Insider’s Nicholas D’Alessandro was on site to capture the launch and although the fog blocked visibility, the audio very clearly indicated a mid-air explosion after re-light with a loud sharp “BANG” a split second after the sound of the Raptors re-igniting for landing.
Other cameras in the area showed an orange glow a fraction of a second after the Raptors began to ignite for the landing-flip maneuver, followed by the loud explosion and debris beginning to rain down all across the launch and landing area.
It’s unclear whether that explosion was from a Raptor or the vehicle’s flight termination system. What is clear, however, is Starship SN11 did not come close to landing and instead performed a “rapid unscheduled disassembly”, or RUD.
“A high production rate solves many ills,” SpaceX CEO Elon Musk said via Twitter. “At least the crater is in the right place!”
Musk later elaborated that engine No. 2 appeared to have issues during the ascent and didn’t reach operating chamber pressure during the landing burn.
However, the plan was for all three Raptors to ignite initially with the least-desirable engine to immediately shut down. So in theory, Musk said, that engine wouldn’t have been needed anyway.
“Something significant happened shortly after landing burn start,” Musk said. “Should know what it was once we can examine the bits later today.”
This is the fourth failed landing attempt in as many months. The first high-altitude prototype, Starship SN8, experienced low header tank pressure, which ultimately starved the engines for propellant during its December 2020 test.
Starship SN9 in February 2021 had an one of its engines fail to re-light during its landing-flip maneuver, causing the prototype to lose control moments before exploding on the ground.
To date, the most-successful prototype flight has been Starship SN10, which successfully landed on the pad in one piece during its March 3, 2021, flight. However, it landed hard because of a thrust issue with one of the Raptors. Additionally, about eight minutes after landing, the test article exploded.
So as things stand now, the next Starship prototype to be rolled out the pad for a high-altitude flight is expected to be SN15.
According to Musk, SN15 could roll to the pad within a few days.
“It has hundreds of design improvements across structures, avionics/software & engine,” Musk tweeted. “Hopefully, if one of those improvements covers this [Starship SN11] problem. If not, then retrofit will add a few more days.”
Apparently the plans for the first Super Heavy prototype, BN1, have changed.
It was initially thought BN1 would be rolled to the Super Heavy mount, potentially before Starship SN15 is moved to its launch pad for various non-flight-related testing.
Instead, Musk tweeted that BN1 is a manufacturing pathfinder and will be scrapped.
“We learned a lot, but have already changed design to BN2,” Musk said. “Goal is to get BN2 with engines on orbital pad before end of April. It might even be orbit-capable if we are lucky.”
Musk’s tweets following the incomplete SN11 test seemed quite optimistic about the future of the program despite it looking like a setback today. It remains to be seen how or if the new presence of the FAA inspector affected this particular launch and how it will affect the investigation and cleanup operation that will follow.
Nicholas D’Alessandro contributed to this report
Video courtesy of SpaceX
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a blog about the International Space Station, called Orbital Velocity.