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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.
The cost? I am doing an analysis of this subject right now for a policy paper I am writing for a Washington think tank, and my preliminary estimate exceeds $41 billion for NASA to fly just one manned flight of SLS. That’s a bit more expensive than the $10 billion NASA is paying SpaceX, Orbital ATK, and Boeing to launch more than a dozen cargo freighters and as many as a dozen manned flights to ISS.
For those elected officials out there who have trouble with math, let’s compare again:
Which costs less and gives more bang for the buck? Can you figure that out, Congressmen and Senators? If you need help I can provide you a few more fingers so you can count above ten.