[AR] LITVC (was Re: Regarding Univerity solid rockets...)
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: Arocket List <arocket@xxxxxxxxxxxxx>
- Date: Sat, 3 Mar 2018 20:09:23 -0500 (EST)
On Sat, 3 Mar 2018, John Schilling wrote:
Nitrous should work, but I'm looking at an old DTIC report that got decent
results from Freon. Looks like their application was for the old Subroc
system, whic as the name implies was meant to be used aboard submarines and
so wanted the safest possible liquids.
Freon LITVC was also used in the second stage of the Polaris A-3 (the
definitive Polaris) and the second stage of Minuteman II and III (*).
Annoyingly, a quick look doesn't reveal *which* Freon it was -- that's a
generic tradename covering a considerable range of compounds.
(* They seem to have been rather coy for a long time about the exact fluid
used in the later Minuteman upper stages, and there is some disagreement
among sources. Hunley's recent "The Development of Propulsion Technology
for US Space-launch Vehicles 1926-1991" says Freon for the II/III second
stage and strontium perchlorate (presumably a water solution thereof) for
the III third stage. )
So, Mark I amateur system uses Freon, and if/when you need the extra
performance you start testing a Mark II using N2O. Carefully, because
it is an energetic oxidizer even if nominally benign at STP. If you get
that working safely and reliably, you can think about things like HAN.
My suggestion for the Mark I would be CO2: reasonably safe, cheap and
widely available, no issues with releasing it into the atmosphere (some of
the Freons are banned now), self-pressurizing, and as a bonus, it's
physically a pretty good imitation of N2O and so the Mark II can use the
same hardware (with a bit more attention to cleanliness and materials).
And while CO2 is reasonably inert at room temperature, in hot gas it's
actually a mild oxidizer -- it's willing to give up one oxygen if a fuel
comes asking.
Henry
Other related posts:
- » [AR] LITVC (was Re: Regarding Univerity solid rockets...) - Henry Spencer
