Nasa's X-37 was peroxide/kerosene. It is the common nontoxic alternative.
I'm having a hard time finding a reliable and sourced citation for
what the DOD's X-37B is now, but I've heard that it's the unusual
combo of peroxide and a hydrazine. It may just be traditional
storables though.
Ben
On Mon, Dec 28, 2015 at 6:02 PM, David Weinshenker <daze39@xxxxxxxxxxxxx> wrote:
On 12/28/2015 01:43 PM, Henry Spencer wrote:
Some things that would have substantially reduced ops costs -- notably,
a switch to nontoxic RCS/OMS propellants -- never made it in, not
because there was any fundamental obstacle, but because it was always
cheaper to carry on with the existing design a little longer.
What sort of alternate propellant system did they have in mind for that?
-dave w