Re: NanoFET thrusters (and electromagnetic catapults)

On 25 Mar, 02:56, Joe Strout <j...@xxxxxxxxxx> wrote:
In article <1174746727.391719.30...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"Alex Terrell" <alexterr...@xxxxxxxxx> wrote:

According to New Scientist, researchers are working on silicon based
rockets that fire out nano particles. These would typically be small
carbon nanotubes or perhaps nano drops of aluminium. The fabrication
is using the same tools for manufacturing chips, and the nanoparticles
are accelerated by voltage differentials through microchannels in the
silicon. "Gilchrist envisions several million nanoFETs being
accommodated on a slice of silicon the area of a postage stamp.

The lead to the article is here, through subscription is required.

http://space.newscientist.com/article/mg19325961.500

A quick google finds this
http://www.engin.umich.edu/dept/aero/spacelab/pdf/STAIF_2007.pdf
and more

Thanks for the pointer, Alex. This is something I've idly speculated
about for a while, but didn't know anyone was actually pursuing.

The efficiency certainly is impressive, and the variable ISp is quite
handy. I wonder what is the limit of thrust/weight for these things.
If we assumed either an external power source, or something very compact
(like maybe a Bussard "polywell" fusion reactor, if those turn out to
work), then I wonder if they could work for Earth launch someday.

That's a tall order. That said, if the rocket is only a fraction of a
millimetre deep, one would assume a very high power to weight ratio.

As for the power supply, it might work, though you'd probably need to
go for a lower ISp, say 1,000 seconds.

I'm still not sure about the Bussard work. On the one hand, the guy
has great credentials. On the other hand, some one like GE should have
bought the rights if it has promise.

.