SLS slows down the more. Bob Zimmerman BehindtheBlack.com

Photo:  Artist's concept, SLS.    NASA/MSFC

https://behindtheblack.com/behind-the-black/points-of-information/update-on-sls-still-aiming-for-march-launch-though-april-more-likely/

The Space Launch System is an American super heavy-lift expendable launch vehicle under development by NASA since 2011.