Sunday, January 18, 2015

Ignition

Ignition! An Informal History of Liquid Rocket Propellants by John D. Clark
The book, published in 1972, is out of print and extremely hard to find, and I only learned about it when reading about FOOF (and you should go read now that article now…and the comments).

The book is just what the subtitle says it is. The style is easy and informal, with real world details (such as noting that the discovery that a mixture is hyergolic usually entails somebody losing his eyebrows). The introduction is by Isaac Asimov.

Why was it written? From the Preface:

There are a few texts which describe the propellants currently in use , but nowhere can he learn why these and not something else fuel Saturn V or Titan II or SS-9. In this book I have tried to make that information available.


This book is written not only for the interested layman—and for him I have tried to make things as simple as possible—but also for the professional engineer in the rocket business. For I have discovered that he is frequently abysmally ignorant of the history of his own profession, and, unless forcibly restrained, is almost certain to do something which, as we learned fifteen years ago, is not only stupid but is likely to result in catastrophe…. So I have described not only the brilliantly conceived programs of research and development, but have given equal time to those which, to put it mildly, were not so well advised. And I have told the stories of the triumphs of propellant research; and I have described the numerous blind alleys up which, from time to time, the propellant community unanimously charged, yapping as they went.

For understanding this incident, note that the card-gap test was a test of how shock-sensitive a compound was. A sample of the compound was put in a heavy tube above a bit of high explosive, separated from it by a number of thin plastic cards. The high explosive was detonated and they checked to see if the compound blew too. The fewer cards that were needed to keep the compound from exploding, the less sensitive the compound was, and the happier the engineers were.
Two people can operate the card-gap apparatus, and three operators is optimum. But when LRPL did this particular job (the feather-bedding at Picatinny was outrageous) there were about seven people on the site—two or three engineers, and any number of rocket mechanics dressed (for no particular reason) in acid-proof safety garments. So there was a large audience for subsequent events. The old destroyer gun turret which housed our card-gap setup had become a bit frayed and tattered from the shrapnel it had contained. (The plating on a destroyer is usually thick enough to keep out the water and the smaller fish.) So we had installed an inner layer of armor plate, standing off about an inch and a half from the original plating. And, as the setup hadn’t been used for several months, a large colony of bats—yes, bats, little Dracula types—had moved into the gap to spend the winter. And when the first shot went off, they all came boiling out with their sonar gear fouled up, shaking their heads and pounding their ears. They chose one rocket mechanic—as it happens, a remarkably goosy character anyway—and decided it was all his fault. And if you, gentle reader, have never seen a nervous rocket mechanic, complete with monkey suit, being buzzed by nine thousand demented bats and trying to beat them off with a shovel, there is something missing from your experience.

You’re heard the phrase “This ain’t rocket science.” This was, and you start to get an appreciation for how tough it really was.

Me? I tried to make my own rocket fuel in high school—a black powder variant with some aluminum powder to overcome the problems caused by the potassium nitrate’s hygroscopic absorption from the tropical atmosphere. A security lapse resulting in too much powder being added to the mix, and I’d never seen a ring-stand rod bent like that before.

Do not attempt to buy this on Amazon. It is a good book, but not worth $3000.

2 comments:

Texan99 said...

You know, there are things I'm supposed to be doing today, not reading the PDF version of "Ignition!" Obviously I'm having a hard time stopping. I wonder if it's out of copyright? It would be a great book for Project Gutenberg.

james said...

I had a very groggy morning the next day...