Green Fuel Spurs New Space Exploration

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The latest development in green energy comes from NASA’s Green Propellant Infusion Mission (GPIM). Teaming up with Ball Aerospace & Technologies Corp and SpaceX, the mission will test an unprecedented and benign alternative to the current toxic space fuel called hydrazine.

Developed by the U.S. Air Force Research Laboratory (AFRL), the new fuel is called AF-M315E–a slightly less wordy moniker for hydroxyl ammonium nitrate fuel/oxidizer. It performs at much greater levels than hydrazine and does so without any of the corrosive fallout.

By offering significantly greater fuel efficiency on top of eliminating numerous health hazards associated with hydrazine, this new fuel explodes the possibilities for scientific exploration.

The “Green” in GPIM mostly refers to the health benefits for people (not to be confused with green technology combating climate change). Like so much of modern life, hydrazine is carcinogenic and extremely toxic. Chris McLean, Ball Aerospace’s principal investigator for GPIM, tells BTRtoday that on a scale of toxicity where water is zero and hydrazine is ten, gasoline is a four. So… not stellar.

The new fuel lands as a one on the scale, which, according to McLean, is as safe as many medications. He posits that, unlike hydrazine, this propellant’s chemical composition lacks anything poisonous. You shouldn’t go drinking gallons of the stuff but then again, McLean laughs, “if you drink enough water, that would be bad for you too.”

Hydrazine’s vapor pressure is such that it leaks easily into the air and lungs of surrounding scientists. As a result, pressurized bunny suits must be worn when handling it to avoid breathing it or exposing the skin to its corrosive effects. Fueling rockets with AF-M315E, meanwhile, can be done in lab coats and eye gear.

Another concern when handling hydrazine is that, as McLean so frankly puts it, “when it’s shipped in trucks – well, it’s an explosive.” This isn’t exactly a surprise, given that it fuels rockets, but McLean calls it “a different level of explosive” than AF-M315E. The latter is so benign that scientists are able to ship it around the country via FedEx.

Photo courtesy of Ball Aerospace.

In short, processes that once devoured many weeks and substantial resources can now take days and cost less money.

Beyond the safety and health improvements, the green propellant offers a new standard for fuel efficiency. Traditional rocket fuel involves a hydrogen fuel and an oxidizer mix, catalyzing into the launch that onlookers eagerly admire. This fuel however, is a denser, single-liquid blend of both fuel and oxidizer. It means more fuel can be stored in existing containers and when used, the propellant performs at a higher level.

For McLean, this is the “beauty” of the GPIM. He assures us, “the green aspect is nice,” but what excites him more is that the new propellant is 50 percent more efficient. He eagerly explains, “if a spacecraft lasted for 10 years on the old fuel, the same exact spacecraft would last for 15 years with this new fuel.” This is an exciting alternative to revamping the technology of an entire vessel.

Once the visually thrilling theater of a launch is over, we easily forget about those orbiting spacecrafts, blanketing the earth in machinery. Machinery needs tending to and McLean reminds us that, as the tides move and pull on those vessels, there’s necessary work to keep them in place. Thrusters are continually fired to maintain the correct orbit, making efficiency critical.

Simplifying launches and improving thrust capabilities opens the door to longer, more scientifically fruitful missions.

Space is cold. This poses a problem when storing hydrazine in very expensive satellites and space stations. When it gets cold, it freezes. When it freezes, it expands like water and breaks the propulsion systems of whatever it is powering. According to McLean, this severely hinders missions to comets or colder celestial bodies like Pluto, because most of the power required to get there and run scientific instruments is used up on maintaining the fuel’s heat.

“Power is a real commodity when you’re in space,” he tells us. “It’s not like you can just plug in another 100 watt lightbulb. You have 100 or 200 watts, total, for the entire spacecraft.”

Photo courtesy of Ball Aerospace.

Instead of freezing, the green fuel turns into glass and doesn’t expand. This glass transition state doesn’t require heating expenditures, and instead that power can be transferred to research technology.

McLean extrapolates that saving on heating power enables some incredible scientific studies, such as searching for life on Mars. While the two may seem only distantly related, they might not be after all. As the south pole of Mars begins its spring thaw, underground geysers reemerge, through which scientists probe beneath the surface of the planet for live organisms.

For those eagerly following projects like SETI and Breakthrough Listen, this certainly sounds like a worthy investment.

Observing these natural wonders, however, is contingent on sensitive instruments that require constant monitoring and tinkering. Delicate scientific fiddling is difficult when all power is spent preventing a freezing, explosive hydrazine fuel catastrophe.

Derision and exhaustion at our national space program litters pop culture. Finally, this technological breakthrough rides in atop a wave of renewed cultural fascination with space. Longer missions means more discoveries, more discoveries means more fuel (so to speak) for the thirsty creative minds of those that have been long disappointed with stale satellites and failed launches.

The first GPIM demonstration is in the works for a 2017 launch in conjunction with a SpaceX rocket. Here’s to hoping it bolsters that tide of societal change.