Space agencies are engaged in a hotly-contested race to send a crew to Mars, with SpaceX and NASA both working on vehicles to reach the Red Planet.
Both the NASA and SpaceX plans in their current form depend on using big chemical rockets for propulsion for a vehicle that will go to Mars. Despite that it is a proven technology, it’s slow. It would take a chemical rocket six months or more to journey from Earth to Mars.
But it may be a third party, Ad Astra that goes ahead, cheers to the plasma rocket technology it’s working on. If it falls out, the plasma engine will allow a larger crew to reach Mars in a third of the time; it would take a traditional rocket, completely changing the landscape of space travel.
Ad Astra CEO, Franklin Chang Diaz who flew on the space shuttle seven times in his NASA days and holds a Ph.D. in plasma physics from MIT, knows a few things about rockets. Through his company Ad Astra Rocket Company he’s been making a plasma rocket engine called VASIMR. It could be the secret to a Mars vehicle that will be more efficient and faster than any old-style chemical rocket. He hopes this might bring about a “paradigm shift in transportation in space.”
Famous, Canadian astronaut Chris Hadfield agrees. Previously this year on a Quirks & Quarks debate about human exploration of space, without specifically talking about Ad Astra, he said,
“I don’t think we’re going to Mars until […] we go from propellers to jets, or whatever that equal will be, from rockets to something else.”
Chemical rockets work using an outdated technology — fire. They burn gases, like oxygen and hydrogen, which then reach high temperatures and produce push as that hot gas discharges through a rocket nozzle.
“This is a very kind of primitive way of transporting anything in space,” Chang Diaz said.
How VASIMR works
The VASIMR rocket engine works a slight differently. There’s no combustion. Rather, high-intensity electromagnetic fields are used to warm up gas to temperatures much hotter than regular burning can reach — millions of units hotter.
When this gas is permitted to escape through a magnetic rocket nozzle, the high temperature turns into a much greater thrust than chemical rockets can offer.
Moreover, the power for the rockets derives from electricity, which can come from solar power or from a nuclear power source on the rocket. So, huge amounts of heavy, bulky chemical fuel aren’t needed and thus the rocket is lighter.
The situation Chang Diaz projects for a Mars mission would be a spaceship about the size of the International Space Station, with a squad of perhaps six people and with a VASIMR engine driven by a nuclear reactor about on the scale of those used in nuclear submarines.
“It will transport about 60 metric tons of cargo to Mars in about 90 days,” he said.
A similar mission powered by chemical rockets would take twice or thrice as long, and would probably require either a larger spacecraft to carry the extra supplies or a smaller crew.
The extra boost also means less exposure to deadly cosmic radiation all along the way, the trip suddenly becomes a whole lot more practical.
Diaz warns that these plasma engines are only for the space-based element of the voyage to Mars. Chemical rockets are still the technology of choice for carrying loads into orbit or for the last stage of landing on Mars.