Innovative Space Propulsion Systems (ISPS), a Houston-based consortium developing rocket engines that run on a proprietary, environmentally benign propellant, announced May 15 that it had recently passed a NASA safety review for flying a demonstration payload to the international space station (ISS) next year.

ISPS has arranged for Space Exploration Technologies Corp. (SpaceX) to fly a thruster test bed, dubbed the ISPS NOFBX Green Propellant Demonstration, to the space station in mid-2013 in the unpressurized cargo compartment of SpaceX’s Dragon spacecraft during one of its NASA-funded cargo missions. Once Dragon is berthed to the station, the orbital outpost’s robotic arm will extract the NOFBX test bed and place it on the outside of the European Columbus module. The test bed, which features a deep-throttling 100-pound-thrust-class engine that burns a nitrous-oxide-based monopropellant called NOFBX, will remain on orbit for one year and undergo a series of in-space performance validation tests, ISPS said in the press release.

ISPS passed NASA’s ISS Payload Safety Review Panel phase 1 review in April.

“Satisfying the safety panel is an incredibly high bar for any new technology,” ISPS President Greg Mungas said in a statement. “Safety is obviously paramount for the space station and this review panel has been thorough and uncompromising in their scrutiny of every technical aspect of our demonstration.”