Franklin Chang Diaz flew on the space shuttle seven times and holds a PhD in plasma physics from MIT, so he knows a few things about rockets. Through his firm Ad Astra Rocket Company he’s been developing a plasma rocket engine called VASIMR. It could be the key to a Mars vehicle that will be faster and more efficient than any old-style chemical rocket.
Chemical rockets work using a very old technology — fire. They burn gases, like hydrogen and oxygen, which then reach high temperatures and produce thrust as that hot gas escapes through a rocket nozzle.
“This is a very sort of primitive way of transporting anything in space,” Chang Diaz said.
The VASIMR rocket engine works a little differently. There’s no combustion. Instead, high-intensity electromagnetic fields are used to heat up a gas to temperatures much hotter than ordinary combustion can reach — millions of degrees hotter.
When this gas is allowed to escape through a magnetic rocket nozzle, the high temperature translates into far greater thrust than chemical rockets can provide…