Bobby riding a missile like a surfboard is much more fantastic that what was in the show. It is one of the "big scenes" that I wanted to see on screen. It is explained in the book that her suit thrusters don't have the range to reach Naomi in time. So she mag boots on to one of the remaining missiles that were orbiting the Razorback (also missing from the show) and Alex flies the missile remotely to Naomi.
It's only cool until you think about the physics of it.
Thrust needs to be applied towards the center as mass if you want to move forwards. Apply the thrust off-center and you start spinning.
The scenario in the book is a great way to start spinning really fast without going anywhere. You'd need to huddle around the missile to align your own center of mass with it (the thrust vectoring can adjust for minor errors), but that's not very cinematic.
It's been a while since I've read the books, I completely forgot about that (so much so that I have to take your word on it). I do remember the missles though.
While I'm sure they could have CGI-ed it, that rescue might have just been too wild/insane to show on TV (it might cause the casual viewer to think the show is too crazy to continue watching).
Or am I missing something?