Hydrazine Sucks

That’s the title of the first chart in Max Vozoff’s talk, which is describing a new monopropellant that Firestar Technologies has been developing up in Mojave. Almost every vehicle, launch and in-space, uses it in some form, despite its toxicity and cost, because up to now there hadn’t been much alternative.

NOFBX is non-toxic and environmentally friendly, and outperforms hydrazine in every respect, particularly for monoprop hydrazine applications. It can literally be poured out on the ground. Will also reduce insurance costs, due to toxicity of crash site if a launch vehicle comes down in an unplanned location.

Firestar has 24 different patents filed, both domestically and internationally (Australia, Europe, Japan and China). Tested in thrusters from 0.1 pounds to a hundred pounds or so.

Showing a comparison matrix that’s too far away for me to read, but comparing Isp, storability (wide temperature range, etc.), throttleability (hundred to one), full thrust in under ten milliseconds, no catalyst bed or heaters, can be mixed up on site with standard chemicals. Acoustic environment much lower due to no need to mix in the chamber — very quiet engines. Self pressurizing, so no need for pressurant (single-fluid system). Less than 5% of the cost of monomethyl hydrazine. Think they can get T/W ratio of a hundred to one on a hundred pound thruster.

18 thoughts on “Hydrazine Sucks”

  1. This sounds big. That’s nitrous oxide based, which has been toyed with since around WWII, but has issues like flashback. If they’ve licked that, they’ve got a great thing.

    This would allow, effectively, longer on-orbit life with the same propellant weight and volume load as hydrazine.

    This could definitely be huge. Good for them; I love seeing a small innovative outfit come up with a worldbeater.

  2. What’s nice to see is the emergence of commercially oriented subsystem developers and contractors. Until now if you were building a launch vehicle or orbital system you either had to be massively vertically integrated, try to get non-aerospace suppliers to work to space standards, or use traditional aerospace subcontractors with prices to match. Hopefully a whole range of such providers will emerge, making it easier and cheaper to develop launchers and on-orbit facilities.

  3. Getting rid of hydrazine would be a huge step in making reusable launch vehicles or even just reusable spacecraft feasible. It’s good to see that there’s lots of innovation bubble up in the spaceflight business these days.

  4. Oh hell yes! Replace that witches brew and move thruster tech into the 21st century finally.

    Minimizing and eliminating as much Haz-Mat from the space business as possible should be a priority goal. This is also a good NACA-like thing for NASA to support too.

  5. Or I should say instead of witches brew, what we commonly call hazardous substances in my business: Methylethyldeath.

  6. A technology I think could become more feasible with this propellant is the integrating of the OMS and LES.

  7. It’s all fun and games until your mixed oxidizer/fuel monopropellant explodes.

    If ordinary N2O can explode (as they learned at the cost of three lives at Scaled Composites), won’t N2O + fuel be even more dangerous?

  8. Yes, I really can’t get my head around how a mixed monoprop even works without a catalyst or a heater.. if it’s self pressurizing, doesn’t that mean you need a relief valve? If you have a relief value spewing a monoprop, isn’t that a thruster?

  9. I may be wildly off base, but isn’t the pressurization control tied to the ratio of gas-to-liquid somehow? That is: Overpressure means stop feeding liquid -> pressure drops quickly as the remaining fuel/flame becomes ‘pilot-light-esque’. All of the ‘venting’ goes straight out the actual rocket nozzle.

    Feeding liquid though can boost pressure very quickly, as the temperature/pressure environment flashes it to gas -and- ignites it.

  10. If it’s self pressurizing it’ll mean the gas pressure is provided by the most volatile component, in theory that means that the composition of the liquid will change as the tank empties, I suppose that needn’t be an insurmountable problem though.

  11. I’ve been trying to find what this stuff is chemically. What I’ve found so far suggests handling similar to propane. One source noted that engines could be fed liquid or gas phase from the tank, no settling needed, which suggests that there isn’t one component that would boil off faster than another.

  12. Trent, I’m not sure why a self-pressurizing tank would need a problematic relief valve. The propane tank on your barbecue is self-pressurizing; so is a butane cigarette lighter, and the N2O tank at the dentist’s office. Propane tanks have relief valves for safety, but they don’t open under normal circumstances. Am I missing something?

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