Space is hard. Interesting to see SpaceX, stage 2, oxygen leak: Initially, normal operation: We start to see an oxygen leak on the right: In a vacuum, the liquid oxygen rapidly sublimates chilling the remaining liquid to form oxygen ice: Here a larger chunk breaks off and is 'falling' towards the exhaust plume: Reaching the plume, it is blasted into infinity: Happily there was enough oxygen to reach orbit and normal engine shutdown. But this shows the wisdom of the next version Raptor engine reducing and eliminating pipe joints. If not perfect, joints are the source of leaks that can terminate flight. Fewer joints, fewer places to leak either fuel or LOX. BTW, one reason for multiple rocket engines on the Falcon 9 and more on Starship, failure of one engine does NOT necessarily fail the mission. As long as the fuel and LOX to the failed engine are shutoff, there will be enough impulse to reach orbit a little later than planned. The fuel burn is so aggressive that within seconds, the remaining engines will be able to continue the mission. Just some of scheduled 'throttle down' events won't happen or be so low or long. UPDATE: The subsequent, 2nd stage ignition in orbit exploded. Some Starlink satellites, five(?), are communicating so there is an effort to see if they reach orbit using their ion engine. Regardless, the booster successfully landed. IMHO, the Falcon 9 and Merlin engines could use a dose of redesign using lessons from Starlink: Fewer parts - easier manufacturing and reliability Optional hot inter staging - more performance Due to fuel density of liquid methane, changing the tanks, the body of Falcon 9 would be impractical until Starship reaches operational stability. Still one can speculate: carbon fiber 1st stage - with reliable booster recovery, the weight savings would add more fuel and improve performance. full flow engines - fewer parts for reliability and better performance. snatch landing - eliminate the landing legs to hover land on 'chopsticks' (not a trivial problem) most useful for return to launch site or other earth landings Bob Wilson
