SpaceX the metals behind Starship and Starlink

Two stages, 39 engines

Starship stands on 33 engines

Starship has two stages: the Super Heavy booster, with 33 Raptor engines, and the ship on top, with six (three for sea level, three for the vacuum of space). Both burn liquid methane and liquid oxygen, and both are meant to land back at the launch tower and fly again.¹

Built like a silo

Rings of stainless steel

Both stages are stacks of stainless-steel rings welded together. The first prototypes used 301 stainless steel, then 304L, which is less brittle and easier to weld; later vehicles use SpaceX's own alloy, 30X.¹ Stainless steel means iron with chromium, at least 10.5%, and usually nickel.²

FeCrNi

Coming home through fire

18,000 black tiles

The ship's belly is covered in about 18,000 hexagonal tiles of silica ceramic.³ They are black and built to take about 1,400°C on the way back through the atmosphere.¹ Here they lift off in a wave.

SiO

Back to the base

Three rings of engines

The booster's 33 engines sit in three rings: 3 in the middle, 10 around them, 20 on the outside.

A 1.2% scale model of the Super Heavy Version 3 booster in a wind tunnel at NASA's Ames Research Center, 2025. NASA/Brandon Torres (public domain).

Inside a Raptor

Two pumps, two preburners, one fire

Raptor burns methane and oxygen in a "full-flow staged combustion" cycle: all of both propellants pass through turbines on their way to the main chamber. That gives high performance, and very harsh conditions inside.⁴

What it is made of

Copper, steel, aluminium

The engine is mostly aluminium, copper and steel.⁴ Copper conducts heat better than almost any metal, which is why combustion chambers are commonly lined with copper alloy and cooled by fuel running through channels in the wall. Here the steel jacket opens to show it.

CuFeAlNi

The hardest place

A superalloy for hot oxygen

On the oxygen side, the turbopump and manifolds carry hot, oxygen-rich gas that would burn ordinary metals. SpaceX makes them from SX500, its own nickel superalloy, similar to Inconel.⁴ Nickel superalloys are the same family as the jet-engine blades in The Engine.

What Starship is for

About 11,000 Starlink satellites

By October 2026 about 11,150 Starlink satellites were in orbit, roughly three-quarters of all active satellites that can manoeuvre, and Starlink had 13.6 million consumer subscribers at the end of September 2026.⁶ SpaceX plans to launch larger Starlink satellites on Starship.

One satellite

Flat-packed, then unfolded

Starlink satellites are flat, so dozens stack inside one rocket. In orbit each unfolds two solar wings. The version 2 "mini", first launched in February 2023, is the one drawn here.⁶

The shortage it dodged

From krypton to argon

To manoeuvre, avoid collisions and finally leave orbit, Starlink satellites use Hall thrusters, which fire a jet of ionised gas. The first versions ran on krypton. "The transition to argon was tricky, but necessary, as krypton is too rare," Elon Musk wrote in 2023. The new argon thrusters have 2.4 times the thrust.⁷ Argon is almost 1% of the air; krypton is about a millionth.

ArKrXe

Why it was short

Ukraine's noble gases

Krypton, like neon and xenon, is a by-product of the plants that separate oxygen from air for steelworks. Before 2022, Ukraine was one of the biggest sources of all three, and Russia's invasion stopped its main plants in Odesa and Mariupol.⁸ The Drone War tells that side of the story.

Radio and light

Antennas below, lasers on top

Flat phased-array antennas on the Earth-facing side talk to dishes on the ground. On top, laser links pass data from satellite to satellite; all newer Starlink satellites carry them.⁶

On the ground

A dish with no moving parts

The Starlink terminal is a flat panel about the size of a pizza box. It tracks satellites racing overhead without turning: hundreds of small antennas, each slightly delayed, steer the beam electronically. That is a phased array.⁶

Layer by layer

• Cover a plastic radome that lets radio through
• Antenna elements a dense grid of small copper patches
• Beam-steering chips rows of small silicon radio chips
• Control board the main processor, GPS and power circuits

Who makes the chips

Made by STMicroelectronics

Security researcher Lennert Wouters, who opened a terminal in 2022, found its main processor is a custom chip made by STMicroelectronics, as are its GPS receiver, motor controllers and power circuits.⁶

The shortage it didn't dodge

Held up by chips

The 2020 to 2023 global chip shortage slowed terminal production. In the last two months of 2021 Starlink signed up only 5,000 subscribers.⁶