These days, kerosene is what gets us around: It’s the fuel used by big commercial planes. Jet fuel is kerosene. It’s relatively cheap, and large jets need “cheap” because a 747’s wings hold enough fuel to fill a swimming pool. You’ve probably already noticed that big airports offer the nostalgic smell of burning kerosene.
What does this have to do with outer space? Plenty. When America first blasted astronauts into suborbital flights inside claustrophobic Mercury capsules, the propellant those Redstone rockets used was, yep, plain old kerosene. It was the most popular rocket fuel of all, and still is. The idea was the brainchild of Russia’s Konstantin Tsiolkovsky (1857-1935), who, exactly a century ago, wrote that kerosene was the way to reach the stars. American Robert Goddard agreed: On March 16, 1926, his groundbreaking kerosene and liquid oxygen rocket made history even though it went up only 41 feet.
Fast forward to the Apollo years, 1969 to 1972, and the wonderful Saturn rocket that got us to the Moon. It was named Saturn because the previous rocket had been called Jupiter, and they decided to continue the sequence. That brilliant public relations idea ended abruptly when they got to
Anyway, the Saturn rocket’s second and third stages used J-2 engines that burned hydrogen and oxygen, like today’s space shuttle. Oxygen is a no-brainer because you need it to make fire in the first place, and it ignites hydrogen. This combination is wonderfully lightweight and packs the greatest wallop for its mass. Its intense blue-white flame appears to create smoke, but it’s really steamy droplets of hot water, so it’s even ecologically friendly. When Challenger blew up in 1986, all the white smoke that enveloped it was, simply, a cloud.
We digress. It won’t surprise you to learn the Saturn’s incredible first-stage engines, each more powerful than any entire rocket ever built, used ordinary kerosene. “What?” you ask. “You mean smelly kerosene powered humans to the Moon?”
Well, I was going to dedicate this article to kerosene, because that liquid took us to the only celestial body on which humans have ever walked, or hopped. But worshipping kerosene is starting to sound stupid, so let’s look at other fuels, too.
When near the Moon, Apollo used super-simple engines that burned hypergolic propellants. They require no ignition because the two chemicals, hydrazine and nitrogen tetraoxide, burst into flame all by themselves, immediately upon contact. If you absolutely need the motor to fire, and don’t want to mess around with sparks or ignition systems, that’s the way to go. They worked every time.
Right now, the space shuttle’s hydrogen and oxygen are as clean and powerful as you can get, but we all know antimatter is much better. Once we get over the technological hurdle of manufacturing it (current worldwide annual production is only 1/100 of a microgram), it will rule supreme. Nothing else offers 100-percent efficiency, where a single gram provides one trillion trillion ergs of energy. Let a penny meet an antipenny — a quarter-ounce of mass — and it could power all the world’s lightbulbs for 20 days.
Maybe someday our houses can use it, too. A feather’s weight of antimatter would run a home for years. But manufacturers will have to be careful. If your thermostat sends a dot too much into the chamber, boom! There goes the whole neighborhood. Up to the Moon.
Maybe we should stick with kerosene.