Rockets could switch to hydrogen for fuel in new space age
Space – the final frontier. So far, we’ve worked out how to prepare for short trips in outer space, but deep space exploration could require finding the right fuels.
When the Saturn V rocket blasted off, to take the first men to the Moon in 1969, it required a significant amount of thrust to simply get off the ground. Hundreds of thousands of gallons of kerosene and liquified oxygen were burnt during its ascent, enabling its passengers to leave Earth on a journey that went down in history.
The Moon landings came and went, and our attention turned towards making shorter hops from Earth to orbital space stations, requiring a fleet of space shuttles to ferry astronauts to and fro, using solid fuel in the process.
Now, as we look ahead to future journeys, including Mars and beyond, we look set to return to using rockets once again. But rather than using the tools of the past, scientists believe hydrogen is the fuel of the future.
Igniting a new trend
Rocket fuel isn’t exactly cheap – each time Saturn V was launched into space, the US Government was estimated to be burning through roughly $185 million per launch, equivalent to over a billion dollars in modern money. It used a combination of kerosene, liquid hydrogen and LOX (liquefied oxygen) to get off the ground.
Kerosene is a popular fuel used for aircraft to this day, otherwise known as paraffin. It can only be created by extensively refining petroleum, meaning it isn’t a sustainable way to power rockets in the long run. Burning kerosene produces lower levels of waste products than most hydrocarbons, but even so, carbon monoxide and nitrogen dioxide are still toxic to most forms of life.
By contrast, scientists believe liquid hydrogen could be a more sustainable way to power the rockets of the future. It’s sourced from one of the most abundant elements in the universe, so we’re likely to find vast supplies of it, even in outer space and burning it produces just water.
As NASA explains in this article, hydrogen had to be ‘tamed’ in order for scientists to harness its potential in liquefied form. This is because, like oxygen, it must be kept at a very low temperature to keep it in liquid form, to serve as a viable form of rocket fuel.
One of the biggest issues that scientists face when getting a rocket off the ground is making it powerful enough to pull away from the Earth without making it too heavy. NASA’s own records estimate that Saturn V weighed 2.9 million kilograms, for the Apollo 11 mission to the Moon in 1969. All that fuel had to go somewhere, in the form of massive tanks built into the structure of the rocket itself.
Rockets powered on pure liquid hydrogen would have the advantage of being much lighter by comparison. This is because hydrogen is one of the lightest substances with a miniscule molecular weight, as opposed to other hydrocarbon-based fuels.
Mars is the obvious next destination for humans, and NASA expects to send people there by the 2030s at the earliest. In order to make it work, however, NASA plans to send a team of astronauts back to the Moon in the mid-2020s, to establish a permanent base of operations. Fortunately, a recent discovery found that the Moon has much more extensive water deposits than we originally thought. This water would be a useful source of hydrogen, and could potentially power those journeys into that final frontier.
Photo credit: NASA and Boeing