Starship Flight 9 had a lot riding on it heading into this flight, after back to back failures of Ship 33 and Ship 34 in the past two flights. After investigations SpaceX seemingly succeeded in solving these issues with Ship 35 making it past Second Stage Engine Cutoff (SECO), however another issue came up during the coast phase.
Flight 9 in Flight (Credit: Max Evans for NSF)
Flight 9
Flight 9 lifted off at 6:36:30 pm CST after a pair of holds near the engine of the countdown related to a Booster engine and a ground side issue with the Ship Quick Disconnect. Booster 14 had a perfect ascent with no engine outs and a perfect hotstaging debuting the new flip sequence. Booster 14 then began its high angle of attack reentry but was then lost at the landing burn, likely due to a Raptor explosion, but so far no confirmation from SpaceX.
Then came Ship 35 which had all the expectations riding on it and for the first time with a Block 2 Ship SpaceX reached SECO. There seemed to be a hot spot on one of the Raptor Vacuum engines regen manifold again, however it did not seem to cause any problems. Unfortunately getting past SECO would be the last milestone Ship 35 would complete as SpaceX could not open the Payload bay door to deploy the Starlink simulators, and teams lost control of the Ship during coast phase.
Leaks from the main tanks lead to the loss of control as Ship uses tank ullage for its Reaction Control System, but the outcome is that SpaceX could not complete the planned Raptor relight and the Ship performed an uncontrolled reentry over the Indian Ocean. Overall Booster 14 performed very well for a first time reused booster even though it was lost during its landing burn. And Ship 35, well it got past SECO, but left much to be desired as none of the actual flight objectives with Ship were completed.
Starship made it to the scheduled ship engine cutoff, so big improvement over last flight! Also, no significant loss of heat shield tiles during ascent.
Leaks caused loss of main tank pressure during the coast and re-entry phase. Lot of good data to review.
Launch cadence for…
— Elon Musk (@elonmusk) May 28, 2025
Flight 7 & 8
Thus far, Block 2 of the Ship has not had the success SpaceX was hoping for. Flight 7 failed shortly before second stage engine cutoff (SECO) due to fires in the attic above the engine bay shielding. These fires were the result of damage from a harmonic response during the Ship’s ascent burn.
The fires ultimately resulted in the vehicle losing control and breaking up in the atmosphere over the Turks and Caicos Islands. However, the Flight 7 booster, Booster 14, completed its full flight profile and was successfully caught back at the launch site, becoming the second Super Heavy booster to be recovered after a flight. Booster 14 was returned to Mega Bay 1 for refurbishment and is now set to fly its second flight on Flight 9.
Booster 14 and Ship 33 in flight during Starship’s seventh flight test. (Credit: BocaChicaGal for NSF)
A little less than two months later, Flight 8 would also see the Ship suffer an anomaly just before SECO. According to a recent update from SpaceX, a sea-level Raptor engine on Ship 34 experienced a hardware failure, resulting in a fire in the engine bay, eventually leading to the vehicle’s breakup and reentry. In the update, SpaceX stated that the harmonic resonance issue from Flight 7 had been fixed and that the problems encountered on Flight 8 were unrelated to Flight 7. However, SpaceX did not address the problem with the Raptor Vacuum engine seen during the SpaceX livestream.
Booster 15 supported Flight 8, and, as with Flight 7, was successfully caught by the “chopsticks” at the launch site. Following the catch, Booster 15 was returned to Mega Bay 1 for refurbishment. It is currently unknown which flight this booster is slated to fly on next, or if it will be assigned a future flight.
Booster 15 is caught following its ascent on Flight 8. (Credit: BocaChicaGal for NSF)
Flight 9’s mission objectives, trajectory, and timelines
Flight 9’s success is riding on many expectations and objectives following the Ship failures of the last two flights and the first reflight of a Super Heavy booster — an essential step toward the program’s goals for reusability.
The Flight 9 trajectory is largely the same as previous flights, with Starship and Super Heavy flying an easterly trajectory out of Starbase. The Ship is expected to perform a splashdown in the Indian Ocean after completing the experiments and in-flight objectives planned for the last two flights. These objectives include deploying eight Starlink satellite simulators, relighting a Raptor engine in-flight, and testing different areas of the heat shield.
The heat shield experiments are also the same as Flight 7 and Flight 8, with Ship 35’s heat shield featuring metallic tiles, an actively cooled tile, missing tiles to test durability on reentry, and tapered edge tiles between the aft flaps and the catch points.
Catch pins on Ship 35. (Credit: Max Evans for NSF)
While the Ship’s trajectory is similar to past flights, Booster 14’s trajectory will differ from its Flight 7 trajectory. SpaceX will not attempt to catch Booster 14 on Flight 9 and will, instead, have the booster perform an experimental reentry to test objectives with a splashdown in the Gulf. During hostaging and the flip for the boostback burn, Booster 14 will not flip in a random direction based on directional push from the Ship, as done on past flights.
On Flight 9, Booster 14 will flip in a controlled direction with the help of a blocked portion of the hotstage ring to push it in a known direction. This new maneuver is expected to lower the amount of fuel reserved in the booster for the flip, allowing more fuel to be used during the ascent burn.
After this new flip and the boostback burn, Booster 14 will reenter Earth’s atmosphere with a higher angle of attack relative to the air flow. This means that, during its return through the atmosphere, the booster will fly more horizontally, creating extra drag and slowing the booster down more. This increased drag, in turn, should allow for less fuel to be needed during the booster’s landing burn, allowing for more fuel on the ascent burn as well. These improvements are expected to refine the booster’s trajectory and provide more fuel to put more mass into orbit.
Super Heavy booster going from hot-staging to tower catch on Starship's seventh flight test pic.twitter.com/Cn7mIOMsaM
— SpaceX (@SpaceX) January 21, 2025
During the landing burn, Booster 14 will utilize a unique engine configuration different from past flights. SpaceX plans to intentionally disable one of the three center engines during the final phase of the landing burn and attempt to use an engine from the center ring of 10 Raptor engines as a backup. This experiment will validate the booster’s ability to perform a landing if an engine-out scenario occurs.
A few changes have been made to Starship’s propellant loading procedures for this flight. The Ship is now set to start loading liquid oxygen (LOX) propellant five minutes and 36 seconds earlier than on Flight 8. Additionally, the Ship will start loading liquid methane (LCH4) two minutes and 19 seconds earlier. It is unknown why SpaceX is beginning propellant loading on the Ship earlier. Super Heavy’s propellant loading procedures for Flight 9 are only a few seconds different from Flight 8.
During flight, the exact timings of events have changed slightly from previous flights, with payload deploy now set to occur about a minute later than what was scheduled for Flight 8.
The propellant loading timeline for Flight 9. (Credit: SpaceX)
SpaceX is targeting no earlier than Tuesday, May 27, for launch, with the flight occurring within a ~90-minute window. There are notices with possible launch dates until June 4, but there are currently only road closures for May 27, May 28, and May 29. Those road closures start at 10:30 am CDT and last until 9:30 pm CDT. It is very likely that with SpaceX not catching the booster, the road could be open sooner than in past flights.
If SpaceX attempts to launch on May 27 but has an abort late in the countdown, it can try again the next day, assuming the issue isn’t major. Teams have upgraded the tank farm to hold more propellant and recapture propellant during detanking procedures.
Ship 35 and Booster 14
Ship 35 has had an interesting journey to launch readiness. It is the first Ship since Ship 24 to have performed at least four separate engine tests. The reason for the extensive engine testing seems to have been the need for at least two Raptor Vacuum engine swaps. It is unknown why SpaceX chose to change these engines, though it is likely out of an abundance of caution.
Ship 35 has many similarities to Ships 33 and 34, at least externally. Over the last few flights, SpaceX has introduced mitigations to try to prevent the failure modes that resulted in the loss of Ships 33 and 34.
Ship 35 is set to have upgrades to its Raptor engine mounts and an improved nitrogen purge system for the ship’s attic. There are likely many other internal changes that can’t be seen, such as the upgrades to solve the harmonic response issue detected on Flight 7 with Ship 33. There is one major outside visible change: the addition of structural catch pins.
Ship 35 is rolled out to the launch site for flight. (Credit: Max Evans for NSF)
These catch pins aren’t bolted onto Ship 35 like the pins used on Ship 33 and Ship 34. Ship 35’s catch pins are integrated into the structure of the payload bay through a massive double plate with stringers to distribute the load. The pins are a slightly different design from what is currently on the booster, as the pin that slots into the landing rail is smaller and thinner.
Booster 14’s journey to Flight 9 started on Feb. 15, 2024, when its construction began. Since then, it has performed a pair of static fires and a flight on Flight 7, where it performed near flawlessly, becoming the second Super Heavy Booster to be caught. Visually, Booster 14 has one major change between Flight 7 and Flight 9: the discoloration from hot staging and reentry.
The only other major change on Booster 14 is on the hot stage ring, where SpaceX has blocked off a section on the side facing the Quick Disconnect to aid in the booster’s flip after stage separation.
Booster 14-2 on Orbital Launch Pad A. (Credit: Jack Beyer for NSF)
SpaceX is targeting no earlier than Tuesday, May 27, for launch, with the flight occurring within a ~90-minute window. There are notices with possible launch dates until June 4, but there are currently only road closures for May 27, May 28, and May 29. Those road closures start at 10:30 am CDT and last until 9:30 pm CDT. It is very likely that with SpaceX not catching the booster, the road could be open sooner than in past flights.
If SpaceX attempts to launch on May 27 but has an abort late in the countdown, it can try again the next day, assuming the issue isn’t major. Teams have upgraded the tank farm enough to recapture enough propellant during detanking and hold more propellant.
Flight 10
After Ship 35 and Booster 14 fly on Flight 9, Ship 36 and Booster 16 are expected to fly on Flight 10, although the Super Heavy booster for Flight 10 has yet to be confirmed. The objectives for Flight 10 will heavily depend on the success of Flight 9. Currently, Ship 36’s engines are being installed, with the ship possibly being rolled out for static fire testing shortly after Flight 9.
Booster 16 is likely ready for a static fire, but it will have to wait for OLP-A’s refurbishment after Flight 9 before testing can begin. However, if SpaceX flies Booster 15 on Flight 10 instead, additional preparations may lengthen the time until it is ready for testing. If Flight 9 goes well and Flight 10 utilizes Ship 36 and Booster 16, the next flight of the Starship program could come within a month after Flight 9.
(Lead image: Flight 9 Hotstaging. Credit: Max Evans for NSF)
