A while back, President Trump mentioned developing a “Space Force” in a speech at Marine Corps Air Station Miramar. Many immediately ridiculed the idea; however, nobody can deny that space is critical to US national security and is only getting more important. The entire country, not just the defense apparatus, is heavily reliant on our network of satellites for GPS, imagery and communications. We must develop the capability to defend our presence in space.
What would a future US Space Force look like? Anything. It could be completely new branch (which might make sense at first for funding), or it could be an outgrowth of the Navy, Air Force and Army (I’m going to lump the Marines in with the Navy here. Rest assured that I haven’t forgotten about Space Marines).
We don’t need a Space Force right away and we might even want to attempt to avoid the complete militarization of space; however, space forces are inevitable. If the US does not develop the capability, then another country will; if not them, then perhaps our future space colonies will revolt (you don’t think that we won’t colonize space, do you?). In the long term, wars will be fought in space, both around Earth and elsewhere. Right now, that is just science fiction; however, the need to defend our space assets now is not.