>>13912546(cont.)
"Phil wanted density. Well, dimethyl mercury was dense, all right —d = 3.07 — but it would be burned with RFNA, and at a reasonable
mixture ratio the total propellant density would be about 2.1 or 2.2. (The density of theacid-UDMH system is about 1.2.) That didn't seem
too impressive, and I decided to apply the 'reducto ad absurdum' method.
Why not use the densest known substance which is liquid at room temperature — mercury itself? Just squirt it into the chamber of a motor burning, say, acid-UDMH. It would evaporate into a monatomic gas (with a low Cp, which would help performance), and would go out the nozzle with the combustion products. That technique should give Phil all the density he wanted! Charmed by the delightful nuttiness of the idea, I reached for the calculator."
Yes, he trolled the other rocket scientists by sugesting using PURE MERCURY as rocket fuel. (I snip here a full page of technical stuff):
"The result was spectacular. With cp = 0.1, and 27.5 percent of the tank volume filled with mercury instead of propellant, the bulk density was 4.9 and the boost velocity was about 31 percent above that of the neat propellant; at cp = 0.2 there was a 20 percent increase with 21 volume percent of mercury. At <p = 1.0, on the other hand, the best you could get was a 2 percent increase in boost velocity with 5 volume percent of mercury. Obviously, a missile with a low <p, such as an air-to-air job, was where this system belonged — if anywhere.
I solemnly and formally wrote the whole thing up, complete with graphs, labeled it —dead pan —the "Ultra High Density Propellant Concept," and sent it off to the Bureau. I expected to see it bounce back in a week, with a "Who do you think you're kidding?" letter attached. It didn't.
Phil bought it.
He directed us, forthwith, to verify the calculations experimentally, and NARTS, horrified, was stuck with the job of firing a mercuryspewing
motor in the middle of Morris County, New Jersey."
