Big Space Delays and Delays and Delays the SLS. Bob Zimmerman,

Apr 08, 2016, 06:18 AM

04-08-2016 (Photo: ‪This artist concept shows boosters separating from NASA's Space Launch System.‬) Twitter: @BatchelorShow. Big Space Delays and Delays and Delays the SLS. Bob Zimmerman, “Government in slow motion: Only six years after program start, NASA has finally chosen Aerojet Rocketdyne’s legacy RL10 rocket engine for the upper stage of the SLS rocket. “The RL10 is an expander cycle liquid hydrogen/liquid oxygen rocket engine typically used on upper stage applications. It was first developed by Pratt & Whitney in the late 1950s and first flown in 1963. It has flown on hundreds of launches, logged approximately 15,000 hot fires, and accumulated more than 2.3 million seconds of hot fire operation time with a demonstrated reliability ratio greater than 0.999 throughout its history. The RL10 – which is used in various forms with Atlas’ Centaur Upper Stage (RL10A-4-2) and Delta IV’s Upper Stage (RL10B-2) – has a history back to the Saturn I’s S-IV Stage. “No other engine exists that can be built in time. Even so, the engine will not be ready for the first SLS launch tentatively scheduled in 2018, but will instead be used on the next two flights. The article also indicates that NASA is planning to delay SLS’s second flight two years to 2023, creating a five year gap which they will use to integrate the RL10 into SLS, while also rebuilding the mobile platform used to move SLS to the launchpad. (For some reason, the reconfiguration installed for the first SLS flight won’t work for later flights.) “The delay to 2023 has not been announced officially, but I have seen too much evidence recently, including statements in this GAO report, that tells me the delay is certain. Furthermore, it seems increasingly likely that the second flight will also be unmanned, and it won’t be until the third flight (as yet unfunded by Coingress) that humans will finally fly on SLS.”