In anticipation of future deep-space missions, NASA has awarded a US$67 million, 36-month contract to Redmond, Washington-based Aerojet Rocketdyne to design and develop an Advanced Electric Propulsion System (AEPS). Based on previous ion thrusters like prototype NEXT and the Dawn mission to the asteroid Ceres, the new propulsion system could used to supply a future manned Mars mission.

Under the contract, Aerojet Rocketdyne will work with NASA engineers from Glenn Research and the Jet Propulsion Laboratory to develop and deliver a propulsion system that includes an ion thruster, a power processing unit, a low-pressure xenon flow controller, and an electrical harness. The power would be generated by an advanced solar array system.

NASA says that the agreement is the latest step in the space agency's Solar Electric Propulsion (SEP) project. By using an ion drive, which replaces chemical rockets with thrusters that use electrons captured in magnetic fields to ionize xenon molecules and accelerate them very high velocity, NASA hopes to increase efficiency by a factor of 100 with double the thrust of current electric propulsion systems.

If the program is successful, NASA anticipates the advanced system going into service by the mid-2020s for commercial and deep-space missions, such as assisting with the unmanned phases of NASA's Asteroid Redirect Mission (ARM) and its Journey to Mars. In the meantime, Aerojet Rocketdyne will build and test an engineering development unit for evaluation and as a model for follow-on flight units – four of which will be built by the company as a follow-on option.

"Through this contract, NASA will be developing advanced electric propulsion elements for initial spaceflight applications, which will pave the way for an advanced solar electric propulsion demonstration mission by the end of the decade," says Steve Jurczyk, associate administrator of NASA's Space Technology Mission Directorate. "Development of this technology will advance our future in-space transportation capability for a variety of NASA deep space human and robotic exploration missions, as well as private commercial space missions."