When millennials were growing up, the idea of being an astronaut was something reserved for the best of the best. Get good grades, take a trip to Space Camp, earn a degree in a related field and you might have the chance to travel to outer space.
Today, if you’ve got a deep enough pocketbook, you can travel to the stars or into low Earth orbit. NASA has its sights set on the moon, but private space travel companies like SpaceX and Virgin Galactic focus on space tourism.
The problem with space tourism is that burning rocket fuel releases massive amounts of CO2 and other greenhouse gasses into the atmosphere. Can we make space travel environmentally friendly?
Launches Are Getting More Frequent
The CO2 emissions from a rocket launch weren’t a problem we needed to consider when NASA was only launching three or four flights a year. During its 30-year run, the space shuttle program only launched 135 missions. In 2021, SpaceX launched 31 missions and was planning 52 for 2022. That’s a rocket launch every week, weather permitting. This list doesn’t even include scheduled flights by Virgin Galactic, Blue Origin, NASA or other space agencies outside the United States during that same period.
The number of launches will continue to climb as space tourism becomes more accessible. Elon Musk plans to use his Starship craft to turn the passenger and cargo airline industries on their ear. The goal is to create long-haul flights that take a fraction of the time. Flying from Texas to Singapore on a regular airliner takes around 20 hours. The same flight on Starship would take less than an hour.
The Falcon Heavy booster used to launch Starship can return to its pad in about six minutes and be ready to fly again in an hour, at least in theory. Imagine this repetitive launch each time someone needs to fly around the world. On average, there are more than 115,000 commercial flights every day. Starship might not replace all of them, but each rocket launch releases more CO2 than your average airliner.
CO2 Isn’t the Only Pollutant
When we think of pollution, the mind immediately focuses on CO2 emissions. However, they aren’t the only kind we need to worry about with rocket launches.
The average rocket launch can easily exceed 200 decibels, 80 decibels above the human pain threshold. As we observed during a 2010 Atlas V launch, the sound waves emitted by these rockets are enough to knock a rainbow right out of the sky. Putting launch pads near populated areas won’t be an option because of noise pollution.
Spaceflight companies can take steps to reduce the noise a rocket launch creates. They can set up sound absorbers or even flood the launchpad with water, which also helps cool the pad and protect delicate launch systems. SpaceX is already planning an off-shore launch and landing platform as an additional line of defense against noise pollution.
Making Spaceflight Environmentally Friendly
Making spaceflight more eco-friendly will be necessary as space tourism becomes more feasible every passing year. The best way to fix this problem involves reducing our overall reliance on fossil fuels.
It is possible to create rocket fuel from hydrogen and oxygen, similar to the small-scale hydrogen fuel cells we may see in cars before too long. This reaction only creates oxygen and water as exhaust and could even supplement the oxygen necessary for rocket ignition in vacuum space.
There is also the problem of the toxicity of traditional rocket fuel. Hydrazine is common but incredibly toxic to human life. NASA is testing a green propellant known as AF-M315E as an alternative to hydrazine. This alternative could find a place on future missions. It underwent its first field test in 2019, with the spacecraft reentering the atmosphere safely in October 2022.
Looking Toward the Stars
Space tourism is becoming a growing trend, and as it becomes more affordable, it will be vital to make it eco-friendly. Companies need to figure out the best way to make their launches do less damage to the planet we call home.