Later this month, a small satellite will dock a space rocket SpaceX Falcon Heavy to enable the world's first demonstration of "green" satellite fuel in space. The satellite is powered by AFM-315, which the Luftwaffe developed more than 20 years ago as an alternative to the typical satellite hydrate of choice, hydrazine. If successful, AFM-315 could dramatically increase the efficiency of satellites, reduce the satellite deployment time from weeks to days, and drastically reduce the safety requirements for storage and handling of satellite fuel – a blessing to mankind and the environment. Looking to the future, scientists working on fuel will play a major role in getting the alien satellite operation going.
Hydrazine is a volatile fuel that will ruin your day ̵
Unlike hydrazine AFM-315 has a similar consistency to water and is viscous. But its fuel density would increase the "miles per gallon" delivered to a satellite by 50 percent compared to the same volume of hydrazine.
McLean says that one of the biggest selling points of the AFM-315 after safety is the fact that it does not freeze. AFM-315 is a liquid salt, which means that it goes through a glass transition at extremely low temperatures instead. This converts the fuel into a brittle, glassy solid that does not expand like frozen water or hydrazine. This attribute prevents fuel lines and reservoirs from cracking under load. In addition, the glass transition point is extremely low, so the fuel on the satellite does not need to be heated – a big burden for other missions. McLean says this would provide more power for other instruments or systems on the satellite, which could open up new opportunities for missions on other planets.
Despite all its advantages, the path of the AFM-315 from conception to launch was a long way off. McLean was first developed by the Air Force Research Laboratory in 1998 as an alternative satellite fuel and was used only to a limited extent because of its high combustion temperature, which was about twice that of hydrazine. This required exotic and expensive materials to prevent damage to the satellite. In the late 2000s, the cost of manufacturing propulsion systems that could handle the heat of AFM-315 was low enough to allow for its use, but no company wanted to run the risk of fueling its satellites with an experimental propellant. According to McLean, AFM-315 would have to prove itself in orbit if the satellite industry ever met with broad acceptance. That's how NASA's Green Infusion Propellant Mission was born.
Originally scheduled for the end of 2015, the Green Infusion Propellant mission fell behind with the delays that plagued the development of the SpaceX Falcon Heavy rocket. On June 24, the Falcon Heavy's second deployment mission is scheduled to run along with several other payloads, including an atomic clock being tested for space navigation.
The Green Fuel Satellite Bus was developed by Ball Aerospace and is equipped with four 1-Newton engines and a 22 Newton engine to test the AFM-315 propellant. During his 13-month mission, he will use the engines to perform orbital maneuvers, such as: For example, lowering the orbit and changing the attitude or inclination to test the performance of the propellant propellant when the demonstration flight is going well. This means that satellites could fly operational missions around Earth 18 months after the demonstration. With a view to the future, AFM-315 could be particularly useful, according to McLean, for exploring cold solar system regions like the Mars poles. It looks like the Red Planet is a bit greener now.
More Great WIRED Stories