NASA’s new pink propellant AF-M315E may not be featured at happy hour anytime soon, but the juice that is powering one of the space agency’s satellites as part of its Green Propellant Infusion Mission (GPIM) rode along on the recent SpaceX Falcon Heavy launch. This nitrate fuel/oxidizer cocktail is supposed to be less toxic than the caffeinated buzz of your morning coffee.
Satellites and robots in space usually drink hydrazine to get going, but it's highly flammable, not to mention extremely toxic — to both humans and the planet. Even workers who get paid to handle it need to wear pressurized full-body hazmat suits. That probably says something about its level of toxicity right there. No wonder NASA needed an alternative, and it’s finally found one, no hazmat suits required. It’s even safe enough to ship via FedEx.
AF-M315E was developed by scientists from the Air Force Office of Scientific Research, but hasn’t fueled anything going into space until until now. This energetic ionic liquid (EIL) is the liquid form of a salt. This is why it beats hydrazine in performance.
EIL molecules have either a positive or negative charge, which make them bond together tightly. That makes such a concoction much denser than hydrazine. Higher density pretty much makes it like an energy drink with a protein boost for spacecraft (same as your car getting 50% more miles per gallon). Spacecraft will get more stamina out of it, traveling further distances and being able to operate longer than they would with hydrazine.
Instead of throwing off dangerous chemical fumes, when this green fuel is combusted, the by-products are hydrogen, carbon dioxide, and water.
Now AF-M3153 is getting its chance to show what it can do in zero-G as the propellant for a Ball Aerospace “SmallSat” spacecraft that will attempt to pull off a series of maneuvers over the next 13 months to prove the pink stuff works. If it passes this test, it could soon be keeping cubesats afloat. The fact that you don’t need much of the pink drink to fly something is also great for a cubesat, which can’t handle an entire propulsion system with large amounts of fuel.
By the way, the fuel isn’t dyed pink to look like rosé; the ingredients, which haven’t yet been made public with the exception of ammonium nitrate, give it the appearance of a blush wine.