After watching the Hazegrayart video If Rockets were Transparent I realized that I didn't really have a clear idea what the Space Launch System (SLS) is capable of doing.
Question: Is SLS capable of launching the core stage into LEO? If so, how much additional payload mass could it put there?
I'll note that this question was raised previously by @leftaroundabout in a comment below Could the SLS reach orbit without solid rocket boosters?
"bonus points:" If so, would that be considered as SSTO?