In article ,
Dick Morris wrote:
For example, it is almost certainly cheaper to use LOX/methane than to
solve the problems of long-term LH2 storage in space. (Slightly modified
RL10s have been run on LOX/methane.)

Could you define "slightly"? A reference detailing the changes would be
appreciated.

The RL10 paper in "History of liquid rocket engine development in the US
1955-1980", AAS History series #13, 1992, alludes to pump and turbine
modifications, plus passage restrictions to increase coolant velocity,
according to my notes. I don't recall it going into much detail, though.

There's also mention of it in the RL10 paper in NASA CP-3112, "Space
Transportation Propulsion Technology Symposium", 1970, and in NASA
CR-54445 and CR-72147 on unorthodox hydrocarbon fuels.

If there's ever been a survey paper going into detail about all the wild
and wonderful things P&W has tried with the RL10, I'm not aware of it.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |