When one hears about ‘going green’, their mind’s eye may conjure pictures of electric cars…or solar panels…or wind turbines. Spacecraft, though, probably aren’t in that mental slideshow. Ball Aerospace, though, is going to change that.
Via their Green Propellant Infusion Mission (GPIM), Ball Aerospace hopes to demonstrate the viability of this ‘green’ propellant when the satellite is launched in 2017 as a secondary payload on a SpaceX Falcon Heavy rocket. Rather than using highly-toxic hydrazine, GPIM will utilize the safer hydroxyl ammonium nitrate fuel (also known as AF-M315E) developed by the Air Force Research Laboratory.
As part of a Technology Demonstration Mission – managed by NASA’s Marshall Space Flight Center in Huntsville, AL – the green propellant will be the foundation for the main propulsion system on the Ball BCP 100-based spacecraft. During the 13-month long mission, engineers will put the spacecraft through its paces –including changes in orbital inclination and altitude — in order to validate that the fuel, and supporting infrastructure, can be declared operational for future agency and commercial missions.
But what does “safer” mean? While hydrazine is both highly toxic and dangerously unstable unless handled in solution, AF-M315E can be safely handled in a standard laboratory environment. This translates to less risk for those who must handle fueling the spacecraft, and should also reduce the cost in supporting such operations as ground processing can be reduced from weeks to days.
However, if the fuel is much safer but performs poorly, then what benefit would it be? The good news is that initial testing indicates that the green propellant performs 50% better per given unit volume than does hydrazine and requires significantly less power to keep the system at proper operating temperature.
If that weren’t enough, it’s also estimated that the new fuel has the initial potential to reduce launching costs by approximately $500,000. It would appear that there are no downsides to this new spacecraft propellant, though that will be clearer at the conclusion of the mission.