Throatless rocket engine.

[LtSharpe]

Click on the underlined carmack says link below to go to his information(Scroll down his journal entires till you see the throatless one). For those that don't know John Carmack is one of the most brilliant software engineers in the world and wrote the gaming engines that all of the major PC games have run on. He's gotten into rockets the last few years as well and competed for the x prize.

Science: Carmack's Throatless Rocket Engine
Space
Posted by CmdrTaco on Sunday August 07, @10:54AM
from the this-is-just-strange dept.
Baldrson writes "John Carmack is working a potentially disruptive technology: A throatless rocket engine. Its made from plain aluminum pipes with few machined fittings. Carmack says : "The great thing about these engines is that it only takes me two nights to machine the parts, so we can test two engines a week if necessary." It scales too: "If this line of tube engine development works out, we can make a 5,000 lbf engine with very little more effort than the test engine." This is what makes disruptive technology development work: Cheap, fast turnaround on on redesign producing technologies that scale. If this works, the NASCAR guys may really start entering space competitions like the X-Cup."

( Read More... | 28 of 40 comments | science.slashdot.org )

 

[shockwaveriderz]

aren't the micro-maxx motors "throatless"? aren't fireworks BP motors, "throatless"... what goes around comes around.....

 

[rocketkyle]

the link isnt working for me...

 

[Micromeister]

Shockie:
yes MM-1 the older plastic cased micro motors were throatless. newer MM-II have a formed throat.

LT:
This isn't NEW! OMG this guys recycling stuff many of us did back in the 50 and 60's. Take a closer look at the early motors being made in the October Skys video, they were welded Flat washers on stright steel pipe. Shoot my very first amateur rocket was built much the some way with a different propellant, but NONE had any throat at all until much later

 

[LtSharpe]

Yes but as opposed to october sky I think these actually work.
As far as the link being down it's because the story was on slashdot.org which is a hugely read tech news site,, when a link gets posted on there the site that's linked gets 'slashdotted' meaning it's knocked off line due to massive numbers of hits.

Originally posted by Micromeister
Shockie:
yes MM-1 the older plastic cased micro motors were throatless. newer MM-II have a formed throat.

LT:
This isn't NEW! OMG this guys recycling stuff many of us did back in the 50 and 60's. Take a closer look at the early motors being made in the October Skys video, they were welded Flat washers on stright steel pipe. Shoot my very first amateur rocket was built much the some way with a different propellant, but NONE had any throat at all until much later

 

[daveyfire]

If you weld a washer over the end of a tube, you're still producing a "throat" whcih constricts the gas flow at the end. It's a very crude nozzle simply missing the convergent/divergent sections. A truely "throatless" motor would have no nozzle at all, relying simply on the erosivity of the motor to provide thrust. I remember Rick Loehr saying something about success with motors like that, but they'd be a huge challenge -- the core diameter is constantly changing, making the motor's thrust vary wildly over the duration of the burn. But for something with a high rate exponent or coefficient, they seemed to work quite well. Interesting concept!