The young Mueller built and flew hobby rockets. “I’d buy them at the local hobby shop,” he said. “I made dozens of those things. I had them hanging above my bed and on the shelves around my bed. Of course they didn’t last long because I’d always lose them or crash them or blow them up or something.” One of the rockets carried a load of crickets. Mueller wanted to see the effect of acceleration on the unsuspecting creatures.317
Mueller’s dream was to become an aircraft mechanic. But during his first year in high school, his math teacher asked him why he didn’t want to become an engineer. Why was his dream to be the one who fixes the plane and not the one who designed it? “If it hadn’t been for that math teacher, I probably would have been a mechanic or a logger,” Mueller said. “Thanks to him, I got the right courses to go to college. And instead, I went off to be an engineer.”318
After a brief visit to California, Mueller knew he one day would come back and work with rockets. But first he needed to attend engineering school. During the summer breaks, he worked as a logger. The work was exhausting. “I knew that I did not want to do that for the rest of my life,” Mueller said. “Because that was the alternative – I either get through college and become an engineer or I’m going to become a logger like the rest of my family. That was very, very motivating. I’d be out there in the bugs and the sticks working and sweating all summer. And I’d just think about, when I get back to school, I’m going to study so hard.”317
After graduation, Mueller moved to California and began working for TRW. Founded in 1901, TRW had worked on the first American ICBM and the engine for the Apollo lunar lander that helped Neil Armstrong and the other astronauts to land on the Moon. Mueller had now designed a prototype rocket engine in his garage. One day, he got a telephone call from a space entrepreneur.
“How much do you think we can get the cost of an engine down, compared to what you were predicting they’d cost at TRW?” Elon asked.
“Oh, probably a factor of three,” Mueller replied.
“We need a factor of ten,” Elon said.288
Elon asked him if he could get the prototype engine to fly. Mueller replied that he could if he had a team with skilled engineers. Elon hired him and Mueller decided to leave his job at TRW. “I had several other opportunities, but when Elon approached me I could see he was different,” Mueller said. “The others always had a gimmick, like a helicopter blade or some miracle technology. Elon just wanted to take the best technology already out there, build a simple vehicle and use the right propellants.”307
For fourteen years, Mueller worked for TRW and can now compare the differences between TRW and SpaceX. It took him and 80 other engineers five years to design an engine intended for the Delta IV rocket, but Boeing decided to choose another engine. All the money and resources used to develop the original engine were wasted. “I can’t think of anything I was responsible for at TRW that ever flew,” Mueller said.71
At SpaceX, Mueller developed a rocket engine together with a team of only 25 engineers. They got the cost of the engine down by a factor of ten, as Elon had demanded, but it was a difficult challenge. “I don’t know if there’s a single thing in that engine that has worked,” Elon said about the early prototypes of the rocket engine. “Where do I start? The turbo pump has been difficult, the thrust chamber assembly’s been difficult, and all the little stuff in between has been difficult, too.”301
Known as the Merlin, the engine developed by Mueller’s team became the first rocket engine produced by an American company in 10 years and the second rocket engine in 25 years. It seems probable that the name originates from the bird Merlin – a small species of falcons. “The Merlin is much more analogous to a truck engine than a sports car engine, which is how all other engines are designed,” Elon said. “Instead of designing it to the bleeding edge of performance and drawing out every last ounce of thrust, we designed Merlin to be easy to build, easy to fix and robust. It can take a beating and still keep going.”303
The Merlin is not an engine that cares about the environment, but that’s not an issue. “You know, rockets contribute, essentially, 0.000001 percent of CO2 or other emissions,” Elon said. “And unfortunately, you really need to burn chemical propellants to get out of Earth’s gravity. There’s no other way to do it.”4 An electric rocket creates thrust by accelerating beams of ions. These rockets are efficient, but the amount of thrust they produce is very small compared to the amount produced by chemical propulsion. Because of the low thrust, you can’t use ion thrusters to launch a spacecraft into orbit, but ion thrusters are ideal for propulsion when the spacecraft is in space.294
To test the rockets, SpaceX needed a test facility. They couldn’t test rocket engines in downtown Los Angeles. Just south of Dallas, in McGregor, Texas, they found a perfect facility. SpaceX bought the site from the Texas banker Andrew Beal, whose own rocket company, Beal Aerospace, had used the site.
In 2000, Beal shut down Beal Aerospace because it was too difficult for a private company to compete with the governmental subsidies of NASA. He explained that the problems for space entrepreneurs are more political than technical. Elon agreed with him. “The Pentagon’s preferred approach is to do long-term, ‘sole-source’ contracts – which means to lock up the entire business for one company,” Elon said. “We’ve been trying to bid on the primary Air Force launch contract, but it’s nearly impossible, because United Launch Alliance, co-owned by Boeing and Lockheed Martin, currently has an exclusive contract with the Air Force for satellite launch. It’s totally inappropriate. Even though we would save the taxpayers at least a billion dollars a year – and that’s a conservative estimate.”305
SpaceX assemble all Merlin engines in Los Angeles and test-fire them in Texas. One part of the test involves feeding a stainless steel nut into the fuel and oxidizer lines while the engine is running. Another test is performed on the launch pad and yet another just before liftoff. For a while after the engines are ignited, the rocket can’t ascend because it’s held down by clamps so Falcon’s computers can analyze the engine performance. When everything looks good, the clamps are released and the rocket can fly away.288
To avoid the risk of getting loose nuts in the engines, SpaceX minimized the number of parts in each rocket. “They’ve designed a solution, but it’s not a good solution, because it’s got several hundred parts,” Elon said about an early design of a propellant tank. “If any of those pieces shake loose, they’ll get stuck and choke the engine. And that will really suck.”71
SpaceX designed Falcon 1 to deliver a payload of 1000 kg into low Earth orbit, which is the space below an altitude of 1200 miles [2000 km] and above 99 miles [160 km]. The rocket could also deliver a lighter payload beyond low Earth orbit into cislunar space, which is the space between the Earth and the Moon. Cislunar is Latin for “on this side of the moon” but also “not beyond the moon.” Beyond the cislunar space is the translunar space.280,380 Launching a rocket to low Earth orbit is the most common altitude. It’s where the International Space Station circulates at a height of 250 miles [400 km], and it’s where the majority of the satellites are.