Author Topic: Space Launch System (SLS) Q&A  (Read 13053 times)

Offline clongton

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Re: Space Launch System (SLS) Q&A
« Reply #40 on: 08/11/2017 12:18 PM »
  Seeing that Project Constellation was looking at 6 RS-68 engines for the core, which would have been less expensive and more powerful than RS-25, how did SLS get to looking at 4-6 RS-25 engines?
Was it merely ablative(RS-68) vs. regenerative nozzle(RS-25) cooling?

Thank you In Advance.

It was determined that the RS-68 would not survive the thermal environment of the proximity to the SRBs long enough to even reach MECO. Providing a regen nozzle for the RS-68 was not an option per USAF sources. Therefore the RS-68 was dropped from consideration and replaced with the RS-25, the next best option.
« Last Edit: 08/11/2017 12:19 PM by clongton »
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