Scott Manley Beta

So one of the interesting things that came out today was SLS + Orion getting taller. Centaur V is getting 50% more propellent, and then a kick stage might be added underneath the service module for lunar orbit injection. I'm trying to think what the kick stage might be based on. It could be as simple as a stripped down service module without the power and panels and just one engine. SpaceX already has the ISS boost kit that fits inside dragon's trunk, it might fit the bill, especially with a Super Draco. Impulse might be able to adapt one of their space tugs to this role. Any other ideas?