Travelling to Mars with immortal plasma rockets

LOS ANGELES: Nearly 50 years after landing on the moon, mankind has now set its sights on sending the first humans to Mars. The moon trip took three days; a Mars trip will likely take most of a year. The difference is in more than just time.

We’ll need many more supplies for the trip itself, and when we get to the Red Planet, we need to set up camp and stay for a while. Carrying all this material will require a revolutionary rocket technology.

The Saturn V was the largest rocket ever built. It consumed an enormous amount of fuel in explosive chemical reactions that propelled the Apollo spacecraft into orbit. After reaching orbit, Apollo ejected the empty fuel tanks and turned on its own chemical rockets that used even more fuel to get to the moon. It took nearly a million gallons of various fuels just to send a few people on a day trip to our nearest extraterrestrial body.

So how could we send a settlement to Mars, which is more than 100 times farther away than the moon? The Saturn-Apollo combination could deliver only the mass equivalent of one railroad boxcar to the moon; it would take dozens of those rockets just to build a small house on Mars. Sadly, there are no alternatives for the “chemical“launch rocket; only powerful chemical explosions can provide enough force to overcome Earth’s gravity. But once in space, a new fuel-efficient rocket technology can take over: plasma rockets.

Plasma rockets are a modern technology that transforms fuel into a hot soup of electrically charged particles, known as plasma, and ejects it to push a spacecraft. Using plasma rockets instead of the traditional chemical rockets can reduce total in-space fuel usage by 90%. That means we could deliver 10 times the amount of cargo using the same fuel mass. Nasa mission planners are already looking into using plasma rocket transport vehicles for ferrying cargo between Earth and Mars.

The main downside to plasma rockets is their low thrust. Thrust is a measure of how strong a “push“the rocket can supply to the spacecraft. The most powerful plasma rocket flown in space, called a Hall thruster, would produce only enough thrust to lift a piece of paper against Earth’s gravity. Believe it or not, a Hall thruster would take many years of continuous pushing to reach Mars.

But don’t worry, weak thrust is not a deal breaker. Thanks to its revolutionary fuel efficiency, plasma rockets have enabled Nasa to perform missions that would otherwise not be possible with chemical rockets. Just recently, the Dawn mission demonstrated the potential of plasma rockets by becoming the first spacecraft to orbit two different extraterrestrial bodies.

While the future of plasma rockets is bright, the technology still has unsolved problems. For example, what’s going to happen to a thruster that runs for the many years it takes to perform round-trip cargo missions to Mars? Most likely, it’ll break. That’s where my research comes in. I need to find out how to make plasma rockets immortal.