Thomas J. Watson of IBM was supposed to have said in 1943 that there was a market for perhaps five computers in the world. He was right, in 1943. By 1951 J. Lyons & Co had built the world’s first business computer. A chain of tea shops built a computer to run their business.

Meet LEO, the world’s first business computer | Science Museum

The tea houses were still seen everywhere in England as late as the 1970s.

These days computers are everywhere, even in greeting cards.

There are three reasons why space industry is expensive now.

• We live at the bottom of a gravity well
• Nobody before Elon Musk was interested in making space transportation affordable
• We don’t know how to exploit resources in space and live there

We live at the bottom of a gravity well

We use chemical energy for most purposes. It is released by burning fuel with an oxidizer. Air is 22% oxygen, so aircraft only need to carry the fuel. A spacecraft goes beyond the atmosphere, so needs to carry oxidizer. Using air for part of the flight has been difficult, so we ignore that possibility. Below I use the word fuel for both fuel and oxidizer.

The problem is that you need fuel to carry the fuel, so you need bigger tanks and rocket engines which also require more fuel, which… you can see where this is going. The maths for this is called the rocket equation. The result is that you get very little into orbit compared to what you started with on the ground.

A solution is to use a staged rocket. The first stage, or launcher, goes most of the way, and the second stage starts when it is going almost fast enough with the launcher falling away with its heavy fuel tanks and engines. The second stage can then carry a useful amount of stuff — the payload — into space. Rockets such as the Saturn V had three stages.

Rocket Science is hard. Just getting things into orbit is hard. Trying to get that kit back is much, much harder. It gets thrown away. That is why spaceflight has been expensive, made more so because it was a wartime activity. The Apollo program was a demonstration that the US could bring more resources to bear than the Soviet Union. Unfortunately, that became the only way to build space technology — because it was always done that way.

Nobody before Elon Musk was interested in making space transportation affordable

Well, that is not strictly true. It is more that he was there at the right time.

The NASA budget had been falling since the heady days in 1970. Apollo scale projects, such as the Space Shuttle, took longer and always cost a lot. By 2000 somebody decided to give Capitalism a try. Musk decided to build rockets just in time to benefit from the Commercial Orbit Transport Services Program (COTS) to carry crew and cargo to the ISS. The program was open to competitive bidding with a specified goal, but the rest was for the bidder to decide. An important innovation was that the bidder specified the targets when payments were made. The bidder had to raise matching funds.

Musk was determined to drive down the cost of spaceflight and did so in several ways:

Vertical Integration

SpaceX manufactures all the critical subsystems and uses off-the-shelf technology where possible, avoiding the profits that each supplier needs to stay in business.

Mass Production

Each Falcon 9 rocket uses nine Merlin engines for the first stage, and one slightly different one for the second stage. About 40 are needed each year, so SpaceX has set up a production line to standardize the process. It will require many more Raptor engines for Starship/Super Heavy so will see increased benefits of scale.

The activity at Boca Chica is all about developing the rockets, procedures and factory in the most effective way. Musk’s real product is factories.

Continuous Improvement (CI)

All of Musk’s businesses work relentlessly to improve everything. Most enterprises would have been happy as soon as Falcon 9 started flying Cargo Dragon to the ISS. Not SpaceX. Every launch was different. The Full Thrust variant could carry more than twice the load compared to the original version, achieved by using the more powerful Merlin 1-D, super-cooling the fuel to make it denser, increasing the size of the first stage, and other things.

SpaceX has shocked the Space Industry by the way CI applies to Starship development. It started with a “flying water-tower” built in a tent on a muddy field. A year later a factory and spaceport is taking form. The project is progressing with rapid prototyping mixed with some spectacular failures, all of them resolved. It is not apparent, but the design that emerges from this process is lean. Traditional techniques lead to overdesign to ensure an adequate safety margin. That safety margin costs mass; for rockets, mass is everything. The SpaceX method makes components as good as they need to be.

Components are re-designed all the time. The first thing that works is usually a kludge of things that did not work so well. The next iteration will cut the number of parts and streamlines it. Failure tells you that you have gone too far.

Reuse

Musk was concerned with the need for reuse from the beginning. His calculations showed that the cost of taking cargo to orbit could be as low as the cost of the fuel. It is criminal to use such expensive equipment once. SpaceX announced its plan to land spent stages in 2011 and started testing in 2012. Most payloads did not require the full capability of the Falcon 9, allowing some of the fuel for the landing. As always, nothing was too hard, and nothing too embarrassing, as this viral video shows.

The plan was to recover the second stage after orbital insertion, but the cost of lifting the heat shielding and extra fuel proved to be too costly. SpaceX is fixing the problem by combining the second stage and payload handling into one with Starship, which will be fully reusable.

Material substitution

Aerospace traditionally uses expensive high-tech materials. One of those is helium used for pressurising fuel tanks. It is costly and will be unavailable on Mars. The Starship Raptor engines will feed methane and oxygen back to the tanks in a process called autogenous pressurisation.

The most significant design change to Starship was when Musk announced the use of stainless steel instead of carbon fibre and aviation alloys. It has many advantages beyond its low price and being readily reusable on Mars.

Long-term Vision

SpaceX has the goal of making humanity multiplanetary. The goal is to build a city on Mars. The timeline is Musk’s working lifetime. The pricepoint is the equivalent of a US middle-class home for fare and necessary cargo for settlers on Mars.

The goal is arguable but is a good one as it ensures a robust transportation system that will open the Solar System to humanity. The price point is a reasonable definition of “affordable” spaceflight.

Everybody knows where the company is going. The management structure and reward system ensure that everybody is in the same team and wants the project to succeed. Designs anticipate future needs, as Cargo Dragon anticipated Crew Dragon, allowing the latter to be developed more cheaply.

We don’t know how to exploit resources in space and live there

Our mining industry depends on people and gravity. An asteroid mine will have neither. I cannot see an automated mine working without engineers and technicians to deal with the things that inevitably go wrong. Our refining processes all depend on gravity to separate stuff (e.g. rocky slag on top of molten iron) and keep things in place. Zero-g will make other things possible, but the best ideas occur to people who work with things all the time.

Human bodies rely on gravity to stay healthy. Long-term space habitats will need rotational gravity, making them big. Building big things is the problem when we can only build stuff on Earth, then lift it to space for assembly. Things will quickly become cheaper when we are up there.

Space is highly radioactive, and people will have to be protected, and we will also need cures for cancer, which is how radiation affects people.

We need to learn all those things, but it will be wrong to wait until we think we know all the answers. That will never happen.