It's another scam to legally take monies from tax payers.

The space force is not going to be "Marines in space."

It's going to be the staff and defense for facilities and missions that involve space in some form. That means if there's a military satellite, they'll be in charge of defending the ground facilities and staffing the ops centers dedicated to that satellite, for example. Tracking stations that NASA uses are often US military installations.

People are already doing precisely that. But some are in the Navy, some in the Army, some in the Air Force. This puts them under a single command.