>>12863576There is a tiny bit of sporadic flow separation, but it's not significant enough to be dangerous to the engine it seems or they'd have added an inward-curling lip like is done with the RS-25. As to the total duration I don't think there's any video of it from start all the way to end, however based on Raptor's mass flow rate it has about three minutes give or take of burn time with 1200 tons of propellant assuming six engines all firing at full throttle. So a full duration burn of Vac-Raptor should be in the 3 minute range.
I see no reason for you to say Raptor might need to be abandoned, compared to legacy engines Raptor is still essentially brand new, with changes as major as it's turbopump size still subject to alteration. In most cases where Raptors have failed to operate correctly it hasn't even been an issue of the engine itself, but an issue with the plumbing upstream from the engine.
Take last flight's engine throttling issue, the engine itself didn't fail in any regard, it lost power because the helium pressurization system used in most rockets is not working very well with the violent maneuvers Starship has to perform, resulting in helium bubbles being ingested by the engine leading to a loss of power. Plumbing and pressurization issue.
In the previous flights engines lost power due to fuel slosh in the CH4 header, plumbing and pressurization issue.
A Starship exploded because of incorrect detanking procedure, human operator error.
A static fire had to be delayed because a throttle setting was too low and incorrectly tripped engine shutoff. Computer error.
Where is the critical problem with Raptor itself that you think *might* require it to be discarded?
