Original URL: http://www.theregister.co.uk/2009/01/22/marmalade_rocket_fuel/

US Army working on 'exploding marmalade' missile tech

You literally don't have to be a rocket scientist

By Lewis Page

Posted in Science, 22nd January 2009 11:58 GMT

US military-funded rocket scientists have turned to food boffins and agricultural engineers for help in their effort to produce exploding marmalade, intended to fuel radical new missiles and spacecraft of the future.

No, really. According to boffins at Purdue Uni in Indiana, there would be many advantages to rocket fuel with the consistency of marmalade - though it needs to be smooth, not chunky.

This is because liquid fuels are very difficult to contain safely, leading to massive handling and storage problems which have seen them mainly used on large rockets. On the other hand, relatively safe and simple solid-fuelled jobs have their disadvantages too. In particular, once you light a solid rocket you can't turn it off or even throttle it up and down. It's going to burn, hopefully at the designed thrust, until all the fuel is gone.

But gel fuels, described as "kind of like orange marmalade without the rind" - apart from being "quite hazardous and reactive", ie basically explosive - by Purdue astronautics prof Stephen Heister, could bridge the gap. They would still have plenty of oof, with "a little more energy than the solid propellants", according to Heister.

But they wouldn't leak and/or corrode tanks and pipework nearly as badly as current liquids. And the potential would be there to throttle an exploding-marmalade rocket up and down, or turn it off for a bit with fuel still remaining.

"You can turn the engine on and off, you can coast, go fast or slow," says the Purdue astro prof. "You have much greater control, which means more range".

Heister and his rocket-scientist chums, however, don't know enough about the way marmaladey-style gel substances behave when squirted through nozzles and mixed with other chemicals. That's where the food and agriculture boffins come in. They're well accustomed to the problems of pumping jam, marmalade, pureed spuds, Dream Topping etc through advanced processing machinery by the thousands of tons; or the handling of all those other bits of animals which get turned into things like tallow, lard, soap, candles, biodiesel, chemical feedstocks etc.

"This is a very multidisciplinary project," says Heister.

The work is funded by the US Army, who hope to see massive performance gains one day by replacing their mostly solid-fuelled missiles with marmalade gel-rockets.

There's more from Purdue here. ®