SpaceX must have a good body of knowledge know how much "coking" is acceptable before a cleaning is required. If they are planning to do a 24-hour turn around on a booster, that doesn't give much time to de-coke the engine.
On the original question, the only real engine work done between static fire and launch is cleaning the fuel film cooling holes (aluminum oxide from the tea/teb) and fuel drain and flush.
Quote from: MechE31 on 04/07/2019 04:24 pmOn the original question, the only real engine work done between static fire and launch is cleaning the fuel film cooling holes (aluminum oxide from the tea/teb) and fuel drain and flush.This cleaning is done without pulling the engines off the vehicle, right?
Quote from: Brovane on 04/07/2019 05:19 amQuote from: Lar on 04/07/2019 02:24 amQuote from: Brovane on 04/07/2019 01:36 amCan we agree that the "man" hours to turn around 9 Merlin Rocket engines to be ready to fire again is considerably less than other equivalent engines because the Merlin rocket engine was designed to be used repeatedly? I think so, yeah... But our opinion counts for a lot less than the view of the CFO of SpaceX....Which goes back to my point, the Merlin was designed for repeated fires. So the static fire is the byproduct of a reusable design. ULA doesn't do static fires because the RD-180 wasn't designed for repeated fires because it isn't a re-usable engine. AFAIK RD-180 IS a reusable engine. It is based on RD-170 which used in the boosters of the soviet space shuttle program, and they had plans for recovering and reusing the boosters.
Quote from: Lar on 04/07/2019 02:24 amQuote from: Brovane on 04/07/2019 01:36 amCan we agree that the "man" hours to turn around 9 Merlin Rocket engines to be ready to fire again is considerably less than other equivalent engines because the Merlin rocket engine was designed to be used repeatedly? I think so, yeah... But our opinion counts for a lot less than the view of the CFO of SpaceX....Which goes back to my point, the Merlin was designed for repeated fires. So the static fire is the byproduct of a reusable design. ULA doesn't do static fires because the RD-180 wasn't designed for repeated fires because it isn't a re-usable engine.
Quote from: Brovane on 04/07/2019 01:36 amCan we agree that the "man" hours to turn around 9 Merlin Rocket engines to be ready to fire again is considerably less than other equivalent engines because the Merlin rocket engine was designed to be used repeatedly? I think so, yeah... But our opinion counts for a lot less than the view of the CFO of SpaceX....
Can we agree that the "man" hours to turn around 9 Merlin Rocket engines to be ready to fire again is considerably less than other equivalent engines because the Merlin rocket engine was designed to be used repeatedly?
That engine has welch plugs? my Google-fu tells me those are also called core plugs or freezeout plugs and are usually found in internal combustion engines...
Quote from: Lar on 04/08/2019 09:39 pmThat engine has welch plugs? my Google-fu tells me those are also called core plugs or freezeout plugs and are usually found in internal combustion engines...burst disks? been a while since I looked at it.