Green Propellant Infusion Mission (GPIM)
Artist's rendering of GPIM on Earth orbit
Mission typeTechnology demonstrator
COSPAR ID2019-036D Edit this at Wikidata
SATCAT no.44342
Mission durationPlanned: 14 months[1]
Final: 1 year, 3 months, 19 days
Spacecraft properties
ManufacturerBall Aerospace
Dry mass158 kg (348 lb)
Start of mission
Launch date25 June 2019, 06:30 UTC[2]
RocketFalcon Heavy
Launch siteKennedy Space Center, LC-39A
End of mission
Decay date14 October 2020[3]
Orbital parameters
Reference systemGeocentric orbit
RegimeLow Earth orbit
Perigee altitude710 km (440 mi)
Apogee altitude724 km (450 mi)

The Green Propellant Infusion Mission (GPIM) was a NASA technology demonstrator project that tested a less toxic and higher performance/efficiency chemical propellant for next-generation launch vehicles and CubeSat spacecraft.[4][5][6] When compared to the present high-thrust and high-performance industry standard for orbital maneuvering systems, which for decades, have exclusively been reliant upon toxic hydrazine based propellant formulations, the "greener" hydroxylammonium nitrate (HAN) monopropellant offers many advantages for future satellites, including longer mission durations, additional maneuverability, increased payload space and simplified launch processing.[4][5][7] The GPIM was managed by NASA's Marshall Space Flight Center in Huntsville, Alabama, and was part of NASA's Technology Demonstration Mission Program within the Space Technology Mission Directorate.

The Green Propellant Infusion Mission launched aboard a SpaceX Falcon Heavy rocket on 25 June 2019, on a test mission called Space Test Program 2 (STP-2).[8] The cost of the program was projected to be US$45 million.[9]



Hydroxylammonium nitrate molecule (NH3OHNO3) is a dense energetic ionic liquid

The propellant for this mission is hydroxylammonium nitrate (NH3OHNO3) fuel/oxidizer blend, also known as AF-M315E.[6][10] Preliminary data indicates that it offers nearly 50% higher performance for a given propellant tank volume compared to a conventional monopropellant hydrazine system.[4][6][10] The Green Propellant Infusion Mission sought to improve overall propellant efficiency while reducing the toxic handling concerns associated with the highly toxic propellant hydrazine.[5][11] The new propellant is an energetic ionic liquid. Ionic liquids are salt compounds in a liquid form whose molecules have either a positive or negative charge, which bonds them together more tightly and makes the liquid more stable.[12]

This new propellant is also expected to be significantly less harmful to the environment.[6] It is called a "green" fuel because when combusted, AF-M315E transforms into nontoxic gasses.[12] The AF-M315E propellant, nozzles and valves are being developed by the Air Force Research Laboratory (AFRL), Aerojet Rocketdyne, and Glenn Research Center, with additional mission support from the USAF Space and Missile Systems Center and NASA's Kennedy Space Center. The Air Force licensed AF-M315E production to Digital Solid State Propulsion (DSSP) to supply the propellant to government and commercial customers.[13]

Following the success of GPIM, the AF-M315E propellent was renamed ASCENT (Advanced Spacecraft Energetic Non-Toxic) in preparation for commercial use and production.[14]


The GPIM system flew aboard the small Ball Configurable Platform 100 (BCP-100) spacecraft bus.[6][11] Aerojet Rocketdyne was responsible for the development of the propulsion system payload, and the technology demonstration mission employed an Aerojet-developed advanced monopropellant payload module as the sole means of on-board propulsion.[10]

Scientific payload

The Defense Department's Space Experiments Review board selected three payloads to be hosted aboard GPIM:


Once proven in flight, the project presents AF-M315E/ASCENT propellant and compatible tanks, valves and thrusters to NASA and the commercial spaceflight industry as "a viable, effective solution for future green propellant-based mission applications".[7][11] According to NASA, the new propellant will be an enabling technology for commercial spaceports operating across the United States "permitting safer, faster and much less costly launch vehicle and spacecraft fuel loading operations."[5] The combined benefits of low toxicity and easy open-container handling shorten ground processing time from weeks to days, simplifying the launching of satellites.[5] The new fuel is 50% denser than hydrazine,[16] meaning more of it can be stored in containers of the same volume. It also has a lower freezing point, requiring less spacecraft power to maintain its temperature.[7]

In addition to its use on lighter satellites and rockets, the fuel's exceptional volumetric storage properties is also being assessed for military uses such as missile launches.[6]

See also


  1. ^ a b "NASA Technology Missions Launch on SpaceX Falcon Heavy" (Press release). NASA. 25 June 2019. Retrieved 9 July 2019. Public Domain This article incorporates text from this source, which is in the public domain.
  2. ^ Bartels, Megan (25 June 2019). "SpaceX Falcon Heavy Rocket Lofts 24 Satellites in 1st Night Launch". Retrieved 9 July 2019.
  3. ^ "GPIM". 14 October 2020. Retrieved 22 January 2021.
  4. ^ a b c "The Green Propellant Infusion Mission (GPIM)" (PDF). Ball Aerospace & Technologies Corp. March 2013. Archived from the original (PDF) on 23 September 2015. Retrieved 26 February 2014.
  5. ^ a b c d e "About Green Propellant Infusion Mission (GPIM)". NASA. 2014. Archived from the original on 10 December 2015. Retrieved 26 February 2014. Public Domain This article incorporates text from this source, which is in the public domain.
  6. ^ a b c d e f "Green Propellant Infusion Mission (GPIM)". Ball Aerospace. 2014. Retrieved 26 February 2014.
  7. ^ a b c "Green Propellant Infusion Mission Project" (PDF). NASA. July 2013. Archived from the original (PDF) on 2 June 2014. Retrieved 26 February 2014. Public Domain This article incorporates text from this source, which is in the public domain.
  8. ^ Clark, Stephen (7 September 2018). "Air Force releases new target dates for upcoming military launches". Spaceflight Now. Retrieved 9 July 2019.
  9. ^ Casey, Tina (19 July 2013). "NASA Sets Its Sights On $45 Million Green Fuel Mission". Clean Technica. Retrieved 27 February 2014.
  10. ^ a b c Spores, Ronald A.; Robert Masse, Scott Kimbrel, Chris McLean (15–17 July 2013), "GPIM AF-M315E Propulsion System" (PDF), 49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, San Jose, California, USA, archived from the original (PDF) on 28 February 2014, retrieved 27 February 2014((citation)): CS1 maint: location missing publisher (link) CS1 maint: multiple names: authors list (link)
  11. ^ a b c Mohon, Lee (2013). "Technology Demonstration Missions: Green Propellant Infusion Mission (GPIM)". NASA. Archived from the original on 3 March 2014. Retrieved 27 February 2014. Public Domain This article incorporates text from this source, which is in the public domain.
  12. ^ a b Scharr, Jillian (16 May 2013). "New Rocket Fuel Helps NASA 'Go Green'". Tech News Daily. Retrieved 10 February 2015.
  13. ^ Carter, Troy (13 March 2019). "As NASA in-orbit test nears, Nevada company licenses Air Force's "green" rocket fuel". TechLink. Retrieved 9 July 2019.
  14. ^ Foust, Jeff (21 January 2021). "Green propellant successfully demonstrated on NASA mission". SpaceNews. Retrieved 22 January 2021.
  15. ^ Gruss, Mike (17 October 2014). "NASA Green Propellant Mission To Host Three Pentagon Experiments". SpaceNews. Retrieved 9 July 2019.
  16. ^ David, Leonard (13 April 2016). "Spacecraft Powered by 'Green' Propellant to Launch in 2017". Space. Retrieved 15 April 2016.