I'm still trying to grasp taking an engine that's flown close to 500 times without an issue and still looking for ways to increase reliability. The gigantic gulf between airline and space operations is getting smaller.
Yup, and SpaceX didn't even make the turbopump for the Merlin 1C.
Quote from: Robotbeat on 04/04/2018 12:40 amYup, and SpaceX didn't even make the turbopump for the Merlin 1C.Wasn't it Barber-Nichols?
Its usually not the time, but the number of starts that kill engines.John
Quote from: livingjw on 04/04/2018 11:56 amIts usually not the time, but the number of starts that kill engines.JohnYup, which is why the number above (>500) is more significant than the accumulated minutes.... And is still too small, so needs to be coupled with demonstrated low impact of failure, something SpaceX demonstrated once with F9 1.0-----ABCD: Always Be Counting Down
Quote from: livingjw on 04/04/2018 11:56 amIts usually not the time, but the number of starts that kill engines.JohnYup, which is why the number above (>500) is more significant than the accumulated minutes.... And is still too small, so needs to be coupled with demonstrated low impact of failure, something SpaceX demonstrated once with F9 1.0
Quote from: meekGee on 04/04/2018 02:37 pmQuote from: livingjw on 04/04/2018 11:56 amIts usually not the time, but the number of starts that kill engines.JohnYup, which is why the number above (>500) is more significant than the accumulated minutes.... And is still too small, so needs to be coupled with demonstrated low impact of failure, something SpaceX demonstrated once with F9 1.0-----ABCD: Always Be Counting DownNot to mention that they are started for testing prior to integration, tested after integration, tested pre-flight and then during flight... that's a lot of starts!
Quote from: Nomadd on 04/03/2018 11:34 pm I'm still trying to grasp taking an engine that's flown close to 500 times without an issue and still looking for ways to increase reliability. The gigantic gulf between airline and space operations is getting smaller.There's no Merlin 1-D engine that's "flown close to 500 times" - there's a big difference between 500 engines that have flown once and a single engine that's flown 500 times!
Unlike slow subsonic aircraft, rocket engines don’t need to run for hours just to get you somewhere.
Quote from: Robotbeat on 04/04/2018 11:24 amUnlike slow subsonic aircraft, rocket engines don’t need to run for hours just to get you somewhere. Not yet anyways...
I wonder how many times they've test fired the same engine on the test stand.
Quote from: rockets4life97 on 04/05/2018 12:19 amI wonder how many times they've test fired the same engine on the test stand.I dont remember how many post-landing firings there were on JCSAT-14's core but those engines probably have the most firings of anything other than dev units.Individual Engine TestMcGregor Static FireCape Static FireLaunchEntry BurnLanding BurnNumerous subsequent firings at McGregor