Can We Use Renewable Energy for Space Travel?

renewable energy for space travel

The Space Race of olden days is over, but the spirit lives on today with the growing desire to conquer Mars. Privatized space programs go toe-to-toe with NASA and CNSA while the mass public looks on and questions the future. 

One of the questions that has always burned in me is “how will we power spacecraft in the future when we’re all out of fossil fuels? What happens if Earth can no longer sustain us, and we have to find alternative energy sources?”

With each passing day, SpaceX and Blue Origin work toward touching the stars, while things down here on Earth are approaching an important crossroads. 

As the conversation around renewable energy grows louder in the face of rising fuel prices and economic inflation rates many of us have never seen, another, less urgent question rises up. We might be able to use renewable energy to power our vehicles, but can we use renewable energy sources for space travel?

Renewable Energy That’s Plausible For Space Travel

Right now, you might be running through the short list of all the renewable energy sources and weighing which ones could possibly work in space. Well, there are a slim few. 

Wind power is obviously a bust, because, no wind. Geothermal is also a no go for obvious reasons, and hydroelectric power falls in the same boat. 

So that leaves us with a few options. Solar power is perhaps the most viable option for powering space travel. It’s already being used in various space capacities, from powering satellites to beaming down solar power to Earth, as sci-fi as that sounds. 

But one of the main problems with using solar power is that it doesn’t provide enough propulsion to exit Earth’s atmosphere. With jet fuel, combustion provides an immense amount of energy all at once, which is how we can send rockets into space and keep them traveling even after they exit our atmosphere. 

With solar power, you need a conduit to harness the power. We might be able to turn solar energy into electricity, but without the right kind of motor or funnel, we won’t be able to use that electricity for anything useful. 

However, when solar energy is thought of as a proponent of chemical propulsion methods, engineers can cut down on overall fuel costs associated with sending spacecraft into orbit. 

Using Solar Power for Farther Travel

NASA has a program dedicated to research and development of solar-powered technologies for use in spacecraft propulsion. SEP, or Solar Electric Propulsion, is designed to “extend the length and capabilities of ambitious new exploration and science missions.”

The way SEP works is fairly straightforward. 

  • Onboard solar arrays collect solar rays and convert it into electricity, to be used for a number of spacecraft systems. Arrays are either in a fan or a window-shade formation. 
  • Energy from the solar arrays is used to power electrostatic Hall thrusters. 
  • Electrons trapped in the magnetic field created by the thrusters then ionize inert xenon gas to create a plasma propellant, which moves the spacecraft forward at a constant speed. 

This technology has been in the works for a long time, but it’s finally starting to come to the forefront of space innovation. Researchers theorize that eventually, SEP will be one of the primary methods for space propulsion. 

There’s still the question of leaving Earth’s atmosphere, and whether solar power can generate enough electricity to launch a craft into space. But, SEP makes it possible to travel longer distances in space without the need for heavy, onboard fuel sources like conventional rockets. 

Futuristic Energy Sources for Space Travel

In science fiction, one of the most common themes is using some kind of nuclear power for space travel. It appears in Star Trek, The Expanse, and plenty of other popular sci-fi novels, shows, and games. 

Nuclear fusion tends to be the technology that’s most used, and it’s different than fission, which is the process used to split atoms (like for the atomic bomb). 

Great strides are being made toward making fusion energy a viable energy source, but because of the size constraints, it’s unlikely that we’ll see them used in spacecraft any time soon. 

Whenever discussing the logistics of space propulsion, I like to go back to Warhammer 40k. The orks in 40k have such large numbers that their collective willpower is enough to psychically force junky spaceships to run flawlessly. If only our own space travel was as simple as that! Willpower is perhaps the most renewable energy source out there!