On Mon, Jul 17, 2017 at 7:33 AM, Henry Spencer <hspencer@xxxxxxxxxxxxx> wrote:
On Mon, 17 Jul 2017, John Dom wrote:
The Mercury capsule 90 % hydrogen peroxide monopropellant RCS which used a
silver type (incl. and pure platinum screens in the end) cat packs had
proven to be unreliable. Such a pain HP thrusters were abandoned in favor of
the NTO/hydrazine fuel biprop. For Gemini, Apollo and all deep space
projects that is.
I tend to think of this as another example of the "devil you don't know"
syndrome: people who'd dealt with the difficulties of peroxide monoprop
liked the idea that NTO/hydrazine wouldn't have those problems, and tended
to overlook the possibility that it might have problems of its own, which it
does. If they'd known then what we know now, the choice would have been
less clear-cut.
