Why yes, this IS rocket science!
Feb. 16th, 2008 10:51 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
ysabetwordsmithFollowing a link from one of my audience members, I rambled my way to this fascinating explanation of how hydrazine rocket fuel works.
I've always been intrigued by rockets -- model rockets, full-size rockets, any rockets. The fuel is always a challenge. I'm intrigued by more modern laser-propelled rockets for that reason. Also I've seen model rocket engines do some bizarre things. There was the one that drove itself six inches into the ground and popped the top off the rocket without launching it off the pad. There was the one that sent my Nova Payloader into spastic convulsions flopping all over the ground, before the finless victim took off horizontally through the crowd about a foot above the ground. (That was the year my mother had the kids in shop class build us a set of chicken-wire barriers for the Young Astronauts Club.) There was the model space shuttle that exploded into flaming confetti, followed by the builder's frantic insistence that he had not rigged it to do that. And of course there were the several rockets per show that went into corkscrew flights, a combination of bad fin alignment (back when you had to assemble your rocket's tail end by hand using actual glue that had to be held in place for about 15 minutes, and before you could just buy a plastic fin module) and poorly mixed fuel in the engine. Post-launch critiques and dissections of failures were part of the fun.
Oh, and that Nova? I rebuilt it and relaunched it and won a ribbon the next year. Though if I remember right it was my Halley's Comet that won the trophy.
I've always been intrigued by rockets -- model rockets, full-size rockets, any rockets. The fuel is always a challenge. I'm intrigued by more modern laser-propelled rockets for that reason. Also I've seen model rocket engines do some bizarre things. There was the one that drove itself six inches into the ground and popped the top off the rocket without launching it off the pad. There was the one that sent my Nova Payloader into spastic convulsions flopping all over the ground, before the finless victim took off horizontally through the crowd about a foot above the ground. (That was the year my mother had the kids in shop class build us a set of chicken-wire barriers for the Young Astronauts Club.) There was the model space shuttle that exploded into flaming confetti, followed by the builder's frantic insistence that he had not rigged it to do that. And of course there were the several rockets per show that went into corkscrew flights, a combination of bad fin alignment (back when you had to assemble your rocket's tail end by hand using actual glue that had to be held in place for about 15 minutes, and before you could just buy a plastic fin module) and poorly mixed fuel in the engine. Post-launch critiques and dissections of failures were part of the fun.
Oh, and that Nova? I rebuilt it and relaunched it and won a ribbon the next year. Though if I remember right it was my Halley's Comet that won the trophy.
Yeah, EP is pretty cool, but....
Date: 2008-02-17 11:39 pm (UTC)EP (electric propulsion, which this method of propulsion falls into) is really cool because the fuel has a very high exit velocity, which means you don't require a lot of it. The problem is, the thrust obtained is really low, so it can take a really long time to get anywhere using it. The exit velocity of chemical propellants is much smaller by comparison, but because there's a lot more of it, you get better thrust and faster travel times. But EP still has its uses; for example, using small EP engines to maintain orbital integrity of satellites in LEO and GEO can extend the useful lifetime of that satellite by 10-15 years. They used to use chemical thrusters, but these didn't work as well because the fuel ran out pretty quickly, and it was hard to scale down the amount of thrust a chemcial rocket could put out.