Let's look at the shuttle. The shuttle is about 40x25x20m across and is used to take loads into space. The Satis is about 60x45x110m in size and I feel it's reasonable from the destruction of Vasuda Prime CBani to say it can do the same thing. Let's compare them then.
In order to put itself in space the Shuttle has to burn 106,261kg of H2
in 629,340kg of O2
+ whatever it gets from the solid fuel boosters to get to escape velocity. Once in orbit it's engines are IIRC basically useless and it it only has a few minutes of burn time on the thrusters it uses in orbit.
The Satis on the other hand doesn't need any external help and can manoeuvre as long as it likes even though it undoubtedly has more mass. So how does it do that? Well we know it's fusion powered so it could be that it works simply by fusing hydrogen and squirting the exhaust out the back to provide thrust. Or it could be that it uses the fusion plant to power some kind of reactionless drive (We know that the GTVA has the capability to generate gravitational fields so let's go with that as an alternative).
Now take the Orion. How much does it weigh? Well going from this page
a Star Wars Star Destroyer weighs 25 million tonnes. An Orion is bigger so let's say 30 million. How much power are you going to need to push that at even a small acceleration using reaction drives? If it takes more than half a million kg of fuel to get power the Shuttle needs to get up to orbital speed how much is it going to take to get an Orion up to the same speed as the Shuttle or Apollo? Bearing in mind that the shuttle could land
in the hanger bay of the Orion.
If someone wants to do the calcs they're more than welcome but for now I still think that we're just as likely to be dealing with a reactionless drive. And if we are then all the stuff about interplanetary runs without using subspace quickly goes out of the window.