Methane powered RS-25E 1.5

(A)(1)  Design an engine that can except a narrow range of  LH2 Methane gelled slushes and crossfeed methane CBC into a LH2 core stage,

(A)(2) This configuration assumes that the Core stage LH2 RS-25E can burn in the first few minutes of flight a diluted crossfeed Methane or Methane gelled in LH2

(A)(3) after the more dense fueled CBC’s separate the core stage flys on with only LH2, does this burn off any coking?

(A)(4) The alternative is a LNG with a large Propane mix CBC with no crossfeed

(A)(5) This CBC in (4) becomes the bases for a EELV system

(B))(1) If The Japanese were to contribute to A methane powered SLS EUS then japan would receive in exchange for this contribution Japanese astronauts in BEO missions

http://global.jaxa.jp/projects/engineering/components/lng/index.html

http://www.ihi.co.jp/ia/en/research.html

selenianboondocks.com/2013/11/random-thoughts-integral-payload-fairing-habitats-as-an-alternative-to-inflatables/

http://www.dlr.de/Portaldata/55/Resources/dokumente/sart/0095-0212prop.pdf

https://yellowdragonblog.com/2014/09/17/booster-propulsion-and-launch-system-request-for-information-rfi-methane-powered-rs-25m/