Spaceflight Insider

NASA’s Green Propellant Infusion Mission propulsion system completed

A green propellant propulsion subsystem was recently delivered to Ball Aerospace for integration into the Green Propellant Infusion Mission spacecraft. The subsystem will be one of three experimental payloads on the spacecraft. Photo Credit: Ball Aerospace

Photo Credit: Ball Aerospace

Aerojet Rocketdyne announced last week that it had completed work on a propulsion system for NASA’s Green Propellant Infusion Mission (GPIM). The GPIM spacecraft, which is scheduled to launch in 2016, will test a nontoxic fuel. The propulsion system was delivered to the mission’s prime contractor, Ball Aerospace in Boulder, Colorado, for integration into the Ball-designed Configurable Platform (BCP) 100 spacecraft bus.

The “green” fuel that GPIM will use, dubbed AF-M315E, is a liquid monopropellant that has a high density and is much safer to handle than hydrazine, one of the fuels currently employed on many launch vehicles and spacecraft. GPIM could serve as a pathfinder, demonstrating how this system could provide a better means to reach orbit.

“GPIM is the culmination of excellent teamwork between NASA, the Air Force, Ball Aerospace and Aerojet Rocketdyne,” said Aerojet Rocketdyne’s Vice President of Advanced Space and Launch Programs, Julie Van Kleeck. “This propulsion system delivery marks the success of more than 10 years of research and development. Following extensive testing, we ended up with a propulsion design using a new, green monopropellant, which will fly into orbit in 2016. The mission will demonstrate the use of this American-made green propellant for multiple applications – a key objective.”

On June 3, members of the Green Propellant Infusion Mission (GPIM) project completed the fourth hot-fire acceptance test on a 1 Newton thruster at Aeroject Rocketdyne’s Facility in Redmond, Washington. Photo Credit: Aerojet Rocketdyne

On June 3, members of the Green Propellant Infusion Mission (GPIM) project completed the fourth hot-fire acceptance test on a 1 Newton thruster at Aerojet Rocketdyne’s Facility in Redmond, Washington. Photo Credit: Aerojet Rocketdyne

GPIM will utilize a propulsion subsystem consisting of a propellant tank and five 1-newton thrusters that will carry this new fuel. AF-M315E was developed by the U.S. Air Force Research Laboratory at historic Edwards Air Force Base located in California.

A release issued by Aerojet Rocketdyne noted that the new fuel offers a 50 percent increase in density-Isp, compared to the conventional chemical propulsion systems, such as hydrazine.

The hydrazine propellant that is currently being utilized in many satellites and launch vehicles is highly volatile, highly toxic, and incredibly corrosive, which makes storing, handling, and loading the fuel a risky proposition, one with significant environmental challenges.

“This is a critical milestone for the GPIM program that will be a game-changer for how we travel in and through space,” said Ball Aerospace’s General Vice President and General Manager of Civil Space and Technology Jim Oschmann. “This new technology offers longer mission durations, additional maneuverability, increased payload space and simplified launch processing for future spacecraft.”

Because the AF-M315E propellant burns hotter than does hydrazine, new metals were required to withstand the higher temperatures in the thrusters aboard the propulsion system. AF-M315E also has a lower freezing point than does hydrazine – this is another improvement over the toxic and highly corrosive fuel, as it requires less of the satellite’s precious power to maintain the propellant’s temperature.

The GPIM payload will fly into space aboard a Ball small satellite or “smallsat”. During the test flight, researchers will order it to conduct orbital maneuvers to demonstrate the performance of the propulsion system during attitude control shifts, changes in orbital inclination, and orbital lowering.

GPIM is sponsored by NASA’s Space Technology Mission Directorate. The project is intended to bring AF-M315E and compatible tanks, valves, and thrusters to an operational level for future NASA and commercial spaceflight missions.

The development of safer high-efficiency propellants such as AF-M315E could be an enabling technology for commercial spaceports and launch providers. Launch vehicle and spacecraft fuel loading could become faster, safer and less expensive. Ground processing time could be significantly reduced, and the building and operation of satellites could be simplified, making this effort an important one in terms of space exploration purposes.

Video courtesy of NASA Marshall Flight Center


Jim Sharkey is a lab assistant, writer and general science enthusiast who grew up in Enid, Oklahoma, the hometown of Skylab and Shuttle astronaut Owen K. Garriott. As a young Star Trek fan he participated in the letter-writing campaign which resulted in the space shuttle prototype being named Enterprise. While his academic studies have ranged from psychology and archaeology to biology, he has never lost his passion for space exploration. Jim began blogging about science, science fiction and futurism in 2004. Jim resides in the San Francisco Bay area and has attended NASA Socials for the Mars Science Laboratory Curiosity rover landing and the NASA LADEE lunar orbiter launch.

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