Participants in Senior Space School this December are fortunate to be visiting one of the world’s leading spaceflight technology companies, Ad Astra Rocket Company.
Ad Astra, founded by physicist and former NASA Astronaut Dr Franklin Chang Diaz, is at the forefront of rocket research and development with its Viable Specific Impulse Magnetoplasma Rocket (VASIMR®) engine. Dr Diaz invented the VASIMR® concept and has been working on its development since 1979.
A student at one of our recent information evenings asked our presenters how plasma technology works. They didn’t have an answer on hand, but we’ve done a little research, so here’s your answer:
The most common current form of rocket propulsion is chemical propulsion which uses a highly explosive chemical reaction inside the rocket to force fuel mass downward and the rocket upward.
Plasma rocket propulsion is a form of electric propulsion. Existing electric rockets use electrical power to accelerate propellant out the back of the engine. While standard electric propulsion has far greater propellant exhaust speed and therefore better efficiency than chemical propulsion, it can only be used in space due to its lower level of thrust. In other words it can’t be used to launch a rocket from Earth.
There are several variations of plasma propulsion, but generally, plasma propulsion technology works on the basis of some kind of force acting on plasma to generate thrust.
Ad Astra’s VASIMR® engine employs plasma technology in a new way that can generate a larger amount of thrust but can also more widely vary its thrust, making it useful in a variety of applications in space and between Earth and space.
The VASIMR® engine uses radio waves to ionize and heat a gas – such as argon, xenon, or hydrogen – to result in superheated plasma. Magnetic fields then accelerate the plasma, converting the ions’ orbital motion into linear momentum in ion speeds around 180,000km/hr, thereby generating thrust.
A projected 200 megawatt VASIMR® engine has the potential to cut travel time from Earth to Mars from 8 months down to 39 days.
Watch here Dr Franklin Chang Diaz at the International Space Development Conference discuss the VASIMR® engine.