That Crew Veh looks like it's stacked on an SRB stage 1.
I see an apparent escape rocket assy on the cap.
This looks entirely ill-considered, as solids can't
be throttled or shut down, and in an emergency could
plow right into the capsule's escape assy.
Traditional laments about shutting down Saturn V
production may commence now.
NASA appears to be returning to yesteryear's designs
without applying yesteryear's safety standards.
SRB stage 1, LH/LO stage 2. Saturn V lamentations have already proceeded. Hopefully NASA has thought up some safety protocols for potential SRB problems...
Why would you want to do that even with a liquid fueled booster?
I don't see anything inherently unsafe about riding a single SRB to space. Remember it was not the O-ring failure on the SRB that directly doomed the Challenger, rather it was the ensuing explosion of the main (liquid) fuel tank.
Actually it's done all the time. They blow a hole in the end opposite the nozzle. It's done with the shuttle's SRBs, and with solid stages on ICBMs as well as other space lauch vehicles.
Still I too don't care for the exclusive use of solids, especially ones as large as the Shuttle SRBs, on manned vehicles.
It would be relatively easy to have "drogue" panels deploy at upper-stage separation to provide the necessary drag if the escape tower can't pull the upper command module away fast enough. Or even have the service module thrusters kick into reverse at separation of the upper module.
This is not difficult.
Albeit, definitionally, it IS ROCKET SCIENCE! :-)