SpaceX Starship IFT-9 Recap

SpaceX's IFT-9 mission showed both progress and stagnation for the Starship program. The booster, reused from IFT-7 with 29 of its 33 Raptor engines, exploded just before landing in the designated water area, possibly due to higher forces from an aggressive return trajectory. All booster engines functioned during relights and shutdowns until the final deceleration burn, where 1 of 13 failed to relight.

Speed Comparison

Speed [km_h] x Seconds [s] (2).png

Altitude Comparison

Altitude [km] x Seconds [s] (2).png

The ship survived engine shutdown this time, unlike in IFT-7 and IFT-8, but faced early issues. Unspecified venting, potentially indicating a plumbing failure, was observed, followed by hot spots on one Raptor vacuum engine. Post-shutdown, the ship rotated along the yaw axis, possibly due to an ullage pressure drop from the leak affecting steering. The Starlink simulator deployment failed again due to a door malfunction, and a key objective—testing the heat tiles, as highlighted by Elon Musk in an interview with Tim Dodd - could not be achieved.

Got to catch up with @elonmusk for a few minutes before today's launch! We were going to chat after today's speech, but unfortunately that changed, but, always happy to talk rockets!!! Join our Flight 9 coverage in 15 minutes!! Best of luck today @SpaceX!!! pic.twitter.com/KJNEtiyJ2d
— Everyday Astronaut (@Erdayastronaut) May 27, 2025

Flight Trajectory Comparison

Booster V1 + Ship V1 (IFT-3 to IFT-6):
Average Speed @ MECO: 5,455 km/h
Average Altitude @ MECO: 66 km
Booster V2 + Ship V2 (IFT-7 to IFT-9):
Average Speed @ MECO: 4,499 km/h
Average Altitude @ MECO: 62 km

MECO (Main Engine Cutoff) occurred at 160 seconds from IFT-5 to IFT-9. Ship V2’s larger, heavier design results in lower speed and altitude as the booster expends more energy.

Starship Program Timeline

Test	Date	Days Elapsed	Version Booster	Version Ship
IFT-1	20.04.23	-	V1 - B7	V1 - S24
IFT-2	18.11.23	212	V1 - B9	V1 - S25
IFT-3	14.03.24	117	V1 - B10	V1 - S28
IFT-4	06.06.24	84	V1 - B11	V1 - S29
IFT-5	13.10.24	129	V1 - B12	V1 - S30
IFT-6	19.11.24	37	V1 - B13	V1 - S31
IFT-7	16.01.25	58	V2 - B14(1)	V2 - S33
IFT-8	06.03.25	49	V2 - B15	V2 - S34
IFT-9	27.03.25	82	V2 - B14(2)	V2 - S35

Starship Specifications

Component	Details
Full Stack
Height	123 m
Diameter	9 m
Payload Capacity (Reusable)	100–150 t
Starship Spacecraft
Height	52 m
Diameter	9 m
Super Heavy Booster
Height	71 m
Diameter	9 m
Source: SpaceX Starship Overview

Remaining Milestones for Starship

Launch: ✅
Stage separation: ✅
Orbit: Almost (reached orbital velocity but slightly below orbit for controlled reentry)
Bellyflop: ✅
Safe booster landing: ✅
Booster reuse: ✅
Reentry without damage: ❌ (flap damage, heat shields fell off)
Safe ship landing: ❌
Ship reuse: ❌
In-orbit refueling: ❌
Leaving low Earth orbit (LEO): ❌
Human life support: ❌
Moon/Mars return & landing: ❌
Lift off from Moon/Mars: ❌

Looking Forward

Elon Musk is hoping for the next 3 flights to happen every 3 to 4 weeks. The FAA might not require a mishap report for IFT9, which puts the ball into SpaceX' court. In that case, it will depend on how long it takes the teams to localize and fix the failures.

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