And then there’s the nozzle at the top, which is where the propellants come together and burn.
These days, rockets all more or less look alike; sure, some are bigger and some are smaller, but they all have a cone-shaped nose at the top, a big tube holding fuel and the rest of the propulsion system underneath, and maybe some fins at the bottom if you’re feeling fancy. However, the first modern rocket, Nell, which launched from a Massachusetts farm in 1926, looked quite different.
Rockets had been around for over a millennium, when the Chinese started packing gunpowder into bamboo or paper tubes to make fireworks. By the 13th century, they had even made rocket-powered arrows for warfare. But with only 2% of the energy released from gunpowder being used for thrust, getting something beyond the stratosphere wasn’t possible.
A physicist named Robert Goddard dreamed of a rocket that could reach the Moon and Mars, and knew that rockets could work without air. He began tinkering with rockets that used gunpowder and other solid fuels, eventually increasing their efficiency by over 3000%. However, getting to orbit would take more than that, so he switched to liquid-fuel rockets. These are more energy dense, and for the same mass of fuel, more energy is released when they burn.
Goddard created Nell, which had two separate chambers to store each propellant (gasoline and liquid oxygen) and a combustion chamber where they could meet up and combust. He also created a frame that served as both a support system and the plumbing that pumps the propellants around. The nozzle at the top is where the propellants come together and burn. Meanwhile, the combustion chamber sits at the top of the rocket, with an igniter to make the propellants ignite. In modern rockets, this would involve a spark plug, but Goddard had a bunch of match heads set alight by his assistant, using a blowtorch on a long pole. This was not ideal, but Goddard was developing the very first liquid rocket and had to work with what he had.
Under the combustion chamber, there is an exhaust nozzle, which speeds up the flow of exhaust and gives the rocket more oomph. This is situated above the oxygen tank, and Goddard even had to put a small asbestos heat shield on top of the tank to protect it from getting too hot. This was because he wanted to keep the flame responsible for combusting the fuel as far away from the propellant tanks as possible.
Goddard’s design might look a little janky to us now, but it worked - Nell blasted off on March 16, 1926 and used up its fuel in under three seconds, climbing 12.5 meters into the air. It may not have been Mars-bound, but it was a historic moment. Goddard kept refining the design up until his death in 1945, and his ideas were certainly an inspiration.
In 1959, NASA named a whole center after him in recognition of his achievements. Rockets used to explore space today look much different to Nell, but it was the simplest possible version of what we use today and the first proof that something like them was possible.
You can’t visit Nell in any museum, but you can immortalise the historic rocket in a pin from DFTBA.com/SciShow. You can also check out some other cool SciShow merch while you’re there too!