Starship is about to launch on its fifth flight, and this time there’s a catch

“We landed with half a centimeter accuracy in the ocean, so we think we have a reasonable chance to come back to the tower,” Gerstenmaier said.

Launch playbook

The Starship upper stage, meanwhile, will light six Raptor engines to accelerate to nearly orbital velocity, giving the rocket enough oomph to coast halfway around the world before falling back into the atmosphere over the Indian Ocean.

This is a similar trajectory to the one Starship flew in June, when it survived a fiery reentry for a controlled splashdown. It was the first time SpaceX completed an end-to-end Starship test flight. Onboard cameras showed fragments of the heat shield falling off Starship when it reentered the atmosphere, but the vehicle maintained control and reignited its Raptor engines, flipped from a horizontal to a vertical orientation, and settled into the Indian Ocean northwest of Australia.

After analyzing the results from the June mission, SpaceX engineers decided to rework the heat shield for the next Starship vehicle. The company said its technicians spent more than 12,000 hours replacing the entire thermal protection system with new-generation tiles, a backup ablative layer, and additional protections between the ship’s flap structures.

From start to finish, Sunday’s test flight should last approximately 1 hour and 5 minutes.

Here’s an overview of the key events during Sunday’s flight:

• T+00:00:02: Liftoff

• T+00:01:02: Maximum aerodynamic pressure

• T+00:02:33: Super Heavy MECO (most engines cut off)

• T+00:02:41: Stage separation and ignition of Starship engines

• T+00:02:48: Super Heavy boost-back burn start

• T+00:03:41: Super Heavy boost-back burn shutdown

• T+00:03:43: Hot staging ring jettison

• T+00:06:08: Super Heavy is subsonic

• T+00:06:33: Super Heavy landing burn start

• T+00:06:56: Super Heavy landing burn shutdown and catch attempt

• T+00:08:27: Starship engine cutoff

• T+00:48:03: Starship reentry

• T+01:02:34: Starship is transonic

• T+01:03:43: Starship is subsonic

• T+01:05:15: Starship landing flip

• T+01:05:20: Starship landing burn

• T+01:05:34: Starship splashdown in Indian Ocean

SpaceX officials hope to see Starship’s heat shield stay intact as it dips into the atmosphere, when temperatures will reach 2,600° Fahrenheit (1,430° Celsius), hot enough to melt aluminum, the metal used to build many launch vehicles. SpaceX chose stainless steel for Starship because it strong at cryogenic temperatures—the rocket consumes super-cold fuel and oxidizer—and has a higher melting point than aluminum.