Fuel

Monomethyl hydrazine is based on hydrazine, which has the chemical formula N2H4. Hydrazine is also used as a propellant and is both unstable and toxic. It may be used as monopropellant (usually after being run through an appropriate catalyst bed), or more commonly as a bipropellant, being hypergolic with nitrogen tetroxide (NTO). Applications of hydrazine have included propelling the Me163B (the first rocket-powered fighter, WWII), on the Viking and Phoenix lander descent engines, and powering F-16 emergency power units. Notably, the thrusters on the spy satellite USA 193 were fueled with hydrazine; an interesting article on the role of hydrazine in the satellite shootdown is here: http://spectrum.ieee.org/aerospace/satellites/us-satellite-shootdown-the-inside-story

Monomethyl hydrazine (MMH) is the result of replacing one of the hydrogens in hydrazine with a methyl group, CH3. It is more stable than hydrazine (can be used in regeneratively cooled engines), and is thus favored as a storable propellant. Because it is still toxic, as well as a suspected carcinogen, great care is taken in handling it. It is most commonly used in hypergolic combination with NTO, such as in the Space Shuttle’s Reaction Control System (thrusters). MMH decomposes into mainly H2, with some CH4, N2, and trace amounts of NH3 and C (soot).

Beginning a Long Explanation

“First of all,” my sister writes, “you should post on what your project is/is trying to accomplish.” … All right, my objective: Characterize the behavior of dual flame fronts in gelled MMH/gaseous NTO as NTO diluent partial pressure and type vary.

This is the simplest way to summarize my project while still preserving the technical aspect. It does, however, lead to a slew of questions: What is involved in “characterizing”? What is a dual flame front? What do MMH and NTO stand for and what are they? Why would you gel them? Why is diluent involved and what am I using? And how does this help babies in Africa?

The Plan

Summer is here! Last summer I tried to step up my posts to once a week, writing on topics suggested by you, my beloved readers. I’m inclined to be less democratic this year. Who cares for the whims of the general populace? I have a thesis to write – and this blog is going to help me. At least, that’s the plan.

Hold me to it: one post per week on some topic related to what I need to cover in my thesis. It will have to be pretty high-level, but at least I’ll be generating content that I can use in some fashion, and it’ll make me think about the “bigger picture”.

If you do feel the dire need to request a post on something, I might be able to satisfy your search for information. We’ll see.

Speaking of thes(es?), this is great: [preface]

“Sometimes a scream is better than a thesis.” -Manfred Eigen