NASA has a new satellite fuel to replace hydrazine!

[thewayne]

Hydrazine is very, VERY nasty stuff! You have to wear a pressurized environment suit when using it to fuel things, it's very toxic.

The new stuff, AFM-315, is less toxic than caffeine. And it's 50% more energetic than hydrazine, which means satellites can have a longer life, assuming they're in a higher orbit, which -315 can help them achieve! It was described as so safe that people sat around in standard lab gear with -315 in plastic jugs as they used it to fuel a satellite. It's a liquid salt and doesn't freeze at extremely low temperatures, from the article it "undergoes a glass transition instead. This transforms the fuel into a brittle, glass-like solid, but it doesn’t cause the fuel to expand like frozen water or hydrazine. This attribute prevents fuel lines and storage containers from cracking under stress. Moreover, its glass transition point is extremely low, so the fuel wouldn’t need to be heated on the satellite—a big power suck for other missions. McLean says this will make more power available for other instruments or systems on the satellite, which could open up new possibilities in missions to other planets."

Very cool stuff. It was actually invented 20 years ago, but people have been slow to adopt it as they wanted to see how it worked out.

Also from the Wired article, "On June 24 it is scheduled to fly on the second operational mission of the Falcon Heavy along with several other payloads, including an atomic clock being tested for deep space navigation.

The green propellant satellite bus was developed by Ball Aerospace and is outfitted with four 1-newton thrusters and one 22-newton thruster that will be used to test the AFM-315 propellant. During its 13-month mission it will use the thrusters to perform orbital maneuvers, such as lowering its orbit and changing its attitude or tilt, to test the performance of the propellant."

https://www.wired.com/story/a-new-fuel-for-satellites-is-so-safe-it-wont-blow-up-humans/

Comments

[dewline]

This sounds useful indeed! Hoping it works out, and that adoption of the new fuel proceeds at warp speed.

[graydon]

I wonder if they're going to retrofit the F-16s.

[dewline]

Could it be that useful to military hardware inside the atmosphere?

(Imagining possible weight trade-offs that might now be possible...)

[graydon]

The F-16 is a single-engine aircraft and deliberately designed to be aerodynamically unstable; you can't lose flight computer power and maintain directional stability. If the engine goes out you need something that starts fast, isn't very heavy, and will generate enough electric power to keep the flight control systems running. The result is an EPU (Emergency Power Unit) that runs off hydrazine (about 25 litres), for pretty much the same reasons satellite thrusters use it; storable, compact, very reliable, no better option.

It's a major handling headache. So if this stuff in the article works out, I can see the USAF setting out to refit all the F-16s to get rid of the need to handle hydrazine.

[thewayne]

Interesting concept, powering the APU in the F-16 with this stuff.  I'm not sure it would work, obviously it would require a complete redesign, not to mention the entire logisitics chain for the APU would have to be changed.  It would be a colossal undertaking, but it could be worth it.  They'd have to make a new APU, and if they could make it a drop-in replacement it would simplify a lot of the logistics.

The F-16 was so monumentally unstable that its common nickname was the Lawn Dart, because that's what it commonly did back at Luke AFB in Glendale.  Those things went down with astonishing frequency.

[graydon]

If the new stuff is thruster fuel, it ought to be able to feed the EPU turbine setup they've already got. I have no idea if it would be a straightforward switch, but "not handling hydrazine, like, at all" has to be a strong inducement. (Every F-16 crash is an extra-special hazmat site because of the hydrazine.)

[dewline]

Points taken under strong advisement.

[seasonoftowers]

After reading Ignition, the thought of a fuel that can sit in beakers, doesn't kill you, doesn't stink to high heaven or go boom if you sneeze at it wrong seems surreal. What's next, peace on earth?

[thewayne]

Peace on Earth? Don’t you go talkin’ crazy, girl! :-)

[thewayne]

That book Ignition looks really interesting! I’ve downloaded it and put it in my iCloud account for further perusal.

I’ve spent a lot of time photographing the Titan II missile (there’s a silo museum south of Tucson, AZ), which uses hypergolic fuel. There was an accident in Arkansas when Bill Clinton was Governor: while performing a service in the silo, someone dropped a ratchet socket, one of these big ones that weighs 5 lbs or so. It fell down the silo, bounced off the wall, off the missile, tore a small hole in the pressurized tank. I don’t remember if it was the oxidizer or the fuel, I think it was the former. Anyway, it was bad, and I think it was less than 24 hours later the missile exploded, hurling the nuclear warhead a quarter to a half a mile away. It couldn’t detonate (theoretically) as it requires the G-force of a launch to arm, but if the warhead casings were to rupture, it could contaminate a lot of area! There’s a book about it that I have and read, but I don’t recall the title off-hand.

[seasonoftowers]

Oh man. Sometimes I wonder how do we even survive as a species.

And yep, Ignition's great :D

[silveradept]

Significantly less toxic, able to do the job, and can do deep space better? That's a lot of win.