A rocket engine with a long pedigree marked a big milestone on Monday. It’s 60 years since the hydrogen-fueled RL10 engine debuted onboard a Centaur upper stage launched from Cape Canaveral on Nov. 27, 1963.

Officials have delayed the launch of a United Launch Alliance Atlas 5 rocket with the European-built Solar Orbiter spacecraft from Cape Canaveral by two days to Feb. 7, a ripple effect from time spent fixing a minor issue last week during a launch vehicle countdown dress rehearsal.

SpaceX test-fired a previously-flown Falcon 9 rocket Monday evening on pad 39A at NASA’s Kennedy Space Center in Florida, setting the stage for a launch later this week carrying the Japanese-built, Qatari-owned Es’hail 2 communications satellite to orbit.