Astronaut exploring Mars

It's always sunny on Mars

How solar rockets can bring Uber to Musk’s Mars city

Virgin Orbit wants to switch from a fuel-burning upper stage to solar energy — and it could support future human habitats on other planets.

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Your typical rocket produces a lot of carbon dioxideup to 300 tons of it. But at the edge of exploration’s new dawn, private spaceflight companies are starting to think it doesn’t have to be that way.

One emergent company, Virgin Orbit wants to switch from a fuel-burning upper stage to solar energy, a move that could support future human habitats on other planets.

Virgin Group founder Richard Branson talks to astronaut Buzz Aldrin.Richard Baker/Corbis Historical/Getty Images

Doing space differently

The satellite launch company has made a name for itself with its visually striking rocket launches. Strapped to the wing of a Boeing 747, the LauncherOne rocket doesn’t need the same launch pads and infrastructure as its competitors.

Virgin Orbit has hosted two successful launches to orbit, but it’s not stopping there. CEO Dan Hart tells Inverse that “we’re developing a solar electric upper stage for our rocket right now.”

That, Hart explains, will enable the company to send rockets beyond low-Earth orbit — to even higher orbits, and maybe even to the Moon, Mars, and beyond.

As SpaceX plans to build a base on the Moon and a city on Mars, launches like these could help these new habitats build up Earth-like infrastructure.

Solar electric propulsion explained

Virgin Orbit plans to build a solar electric propulsion system for the upper stage of its LauncherOne rocket. That’s the part of the rocket that carries the satellite to its desired orbit.

The idea builds on existing satellite technology that uses solar energy and gas to create large amounts of thrust over a short time. NASA explained in 2004 how satellites can use a five-part system to create thrust.

All this can produce a much higher speed than traditional rockets. Where the space shuttle could reach 18,000 mph, an ion thruster can reach up to 200,000 mph.

The tradeoff is a much lower acceleration, with thrust of just 0.1 pounds. That means they’re no good for leaving Earth, as you need large amounts of thrust to escape gravity.

All this means much less fuel is required to power the thruster. Dawn, a NASA probe launched in 2007, used its thruster for 27 hours with just 10 ounces of its total 937 pounds of fuel. Deep Space 1, which launched in 1998, also used ion thrusters.

Want to know more about SpaceX’s rocket fuel, Virgin Orbit’s 2021 milestone, and whether or not Hart predicts a future on another planet? Read the full interview with CEO Dan Hart, only in MUSK READS+.

A solar electric-powered upper stage could help small rockets send bigger payloads into space. A 2007 study from the NASA In-Space Propulsion Technology Project Office concluded that these upper stages “can trade trip time for mass performance,” which means customers can place bigger payloads into orbit at once.

“For me, it's science fiction becoming reality,” Hart says. “I grew up with Star Trek, and they talked about ion propulsion or impulse engines or things like that, and now they're on almost every spacecraft that we launch.”

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