Re:SLS vs. Starship
by pfdietz on Saturday November 14, 2020 @07:49AM
(#25092006)
Yes, Merlin was designed to be cheap. That's why it's cheap. Being reusable was not an impediment to it being cheap. Being reusable is not an excuse for being expensive.
A cheap rocket engine needs a cheap development process, which means you want your test articles to last a long time. Far from being an obstacle to cheapness, reusability is a requirement for an affordable engine development program.
Let's go way back to Usenet and listen to Henry Spencer on this subject.
"To reiterate my original point: almost any regeneratively-cooled liquid rocket engine is reusable, even if it was built for expendable vehicles. The design requirement for the F-1 was 20 starts and 2250s of firing; as part of the test program, six of them accumulated over 5000s each."
A cheap rocket engine needs a cheap development process, which means you want your test articles to last a long time. Far from being an obstacle to cheapness, reusability is a requirement for an affordable engine development program.
Let's go way back to Usenet and listen to Henry Spencer on this subject.
https://yarchive.net/space/rocket/rl10.html
"To reiterate my original point: almost any regeneratively-cooled liquid rocket engine is reusable, even if it was built for expendable vehicles. The design requirement for the F-1 was 20 starts and 2250s of firing; as part of the test program, six of them accumulated over 5000s each."