The builder

Elon Musk

by Joe Miller

Engineer, entrepreneur and the most powerful private force in spaceflight. He started SpaceX in 2002 with one goal: make life multiplanetary.

1971Born June 28 in Pretoria, South Africa

2002Founds SpaceX

~700Falcon rocket launches by August 2026

2026SpaceX becomes a public company in June

Early years

Musk grew up in South Africa, taught himself computer programming and sold a video game he wrote at age 12. At 17 he moved to Canada, then studied physics and economics at the University of Pennsylvania. In 1995 he started Zip2, an online city-guide company, and sold it in 1999. He then co-founded X.com, which became PayPal; eBay bought it in 2002 for $1.5 billion.

SpaceX

Musk founded SpaceX in March 2002. Its first three rocket launches failed; the fourth, in 2008, reached orbit and saved the company. Since then:

Reusable rockets. Falcon 9 boosters land upright and fly again, which cut the cost of reaching space. By August 2026, Falcon rockets had launched nearly 700 times.
Astronauts. In 2020, Crew Dragon became the first private spacecraft to carry NASA astronauts to the space station.
Starlink. Thousands of internet satellites that work anywhere, even when the ground networks are down.
Starship. The largest rocket ever built, made of stainless steel and designed so both stages can be caught and reused. Flight 15, aiming to catch both stages, is set for no earlier than November 13, 2026.
A public company. SpaceX merged with Musk's AI company xAI in February 2026 and began trading on the stock market in June 2026, valued at well over $1 trillion.

Tesla and the Optimus robot

Musk led Tesla from a small startup to the world's best-known electric car company. Tesla is now building Optimus, a humanoid robot about 5 feet 8 inches tall, with production lines being installed in Fremont, California. In April 2025, Musk wrote that Starship would "hopefully depart for Mars" with Optimus explorer robots aboard.

His other companies include Neuralink (brain implants), The Boring Company (tunnels), and X, formerly Twitter.

Moon first, then Mars

For years Musk aimed at a city on Mars, with fleets of Starships leaving every 26 months, when Earth and Mars line up. The late-2026 Mars window has come without a Starship launch, because the rocket and its in-orbit refueling are not ready. In 2026 Musk said SpaceX would focus first on a self-growing city on the Moon, which he says is faster to build, since the Moon is only days away. Mars remains the goal; the next windows are around late 2028 and 2031.

Why Musk took up von Neumann's idea

What Musk himself has said:

April 2025: Starship would "hopefully depart for Mars" carrying Optimus explorer robots. Robots go first; people follow.
March 2026: on X, Musk said Optimus together with solar power will become the first von Neumann probe, a machine able to fully copy itself from raw materials, including materials found in space.
2026: he described the Moon city he wants as "self-growing", one that keeps building itself.
October 29, 2026: exploring the galaxy with von Neumann probes by 2100 would be a great result for civilization.

Why the idea fits his goal. The reasons below are this site's explanation of the engineering, not Musk's own words:

The shipping problem

Everything launched from Earth is expensive, and a city of a million people needs millions of tons of steel, glass and machines. You cannot ship that. A machine that builds from local rock and ice solves it.

Robots go first

Robots need no air, food or water, and they can wait out radiation and dust storms. They can build the landing pads, power plants, fuel plants and homes before the first people arrive.

Sun and sand

Solar panels are made mostly of silicon, which is plentiful on the Moon and Mars. Robots that make solar panels make their own power, and that power runs more robots.

Doubling beats adding

Ship 100 robots and you have 100. Ship 100 robots that can each build one more per year, and after 10 years you have over 100,000. That is von Neumann's insight.

Every world a launch pad

Once a world can build robots and make fuel, it can build and fuel rockets too. Mars, then the asteroids, then the moons of Jupiter and Saturn each become a new starting point.

Humans in charge

Musk has said he would rather people stay in control of AI. In his version, the self-copying machines are the tools that carry people, not a replacement for them.

The plan, step by step

1. Earth · Build the tools: reusable Starship, Optimus robots, AI to run them, and in-orbit refueling (first test planned for 2027).

2. The Moon · A two-day trip, so it is the test bed: robots start a "self-growing" city, mine ice, make fuel and solar panels.

3. Mars · Robots land first in the icy plains of Arcadia Planitia, build the fuel plant and shelters, then crews follow. Launch windows come every 26 months.

4. Mars builds rockets · Factories on Mars make steel, panels, robots and fuel, so new ships no longer come from Earth.

5. Beyond · Self-copying probes hop to the asteroid belt and the outer moons, and someday to other stars. Musk's hoped-for date for exploring the galaxy: 2100.

This is a decades-long vision, and some steps, especially a factory that can build a complete copy of itself, have never been done. Experts are skeptical of Musk's dates.

How Musk's pieces fit von Neumann's idea

A von Neumann probe needs a ride, a builder and local materials. These drawings are generic, not company designs.

What a von Neumann probe needs	What Musk is building
A ship that flies again and again	Starship, fully reusable
Hands to build things	Optimus humanoid robots
Fuel from local materials	Starship burns methane and oxygen, which can be made on Mars from buried ice and the carbon dioxide air
A brain to run it all	xAI's artificial intelligence, now part of SpaceX
A factory that makes more factories	Not yet. This is the hardest step, and no one has built one

On October 29, 2026, Musk posted that exploring the galaxy with von Neumann probes by 2100 would be a great result for civilization. Musk's timelines are famous for slipping, so treat his dates as goals.

Musk's detailed plans Take the free Elon Musk test