Our current level of technological prowess is severely hindering efforts to explore the solar system. Nine months to get to Mars—who's got that kind of time? If a new breed of ion thruster currently under development at the Australian National University is successful, we'll get to the Red Planet in a third of the time.
The drive is known as a Helicon Double Layer Thruster (HDLT) and is being developed with a $3.1 million (AU) grant from the Department of Industry, Innovation, Science, Research and Tertiary Education. The SP3 Laboratory at Australia's National University (ANU) is collaborating with European firm EADS-Astrium and the Surrey Space Center on the engine design.
The ANU is currently building a testing facility at the the Mount Stromolo observatory to put the HDLT through its paces once complete. "A number of Australian universities teach aerospace and mechantronics. Up until now, there's been nowhere for them to test their spacecrafts – they have to go overseas," explained chief researcher Professor Rod Boswell. "So this will really be providing a major service, not only in Australia, but also in Southeast Asia." But what exactly is an HDLT?
An HDLT is a variety of ion thruster designed specifically for simplicity and weight savings. It works just like other ion thrusters—generating thrust by expelling charged particles—however it does so with no moving parts. Instead, a gas (either xenon or krypton) is injected into the source tube. The tube is bombarded with 13.56 MHz radio waves emitted by a pair of antenna wrapped around the tube, which creates a double-layer electrical field that basically acts as a nozzle, directing the stream of ions as it exists the engine. These radio waves excite the gas molecules to the point of plasmafication and they exit the source tube from its open end. As ANU explains, this double-layer is an intrinsic part of the thruster design: