4

When the first Star Destroyer is disabled it just angles down slightly but doesn't fall into orbit or crash. However when they both crash into each other they both start falling into orbit and crash into the ring.

Why is this?

7
  • The novelisation just says that they start to fall and then gravity takes them. Perhaps they were outside the gravitational pull of the planet :-)
    – Valorum
    Dec 23, 2016 at 9:44
  • 1
    @Valorum Gotta love star wars physics
    – TheLethalCarrot
    Dec 23, 2016 at 10:54
  • 1
    It's a world where magic is an actual thing and you're worried about a couple of Star Destroyers?
    – Valorum
    Dec 23, 2016 at 11:02
  • @Valorum If they came right at my face I think I'd shit myself, so yeah I am... from a certain point of view
    – TheLethalCarrot
    Dec 23, 2016 at 11:03
  • 4
    You're not supposed to think about it. You're supposed to be awed by the special effects and clap like a delighted fool when you see digi-Leia.
    – Valorum
    Dec 23, 2016 at 11:04

2 Answers 2

5

It's known that Star Destroyers can hover in atmosphere, but that it takes an astonishing amount of power for them to do so (presumably to counteract the gravitational force between the planet and the ship).

The novelization describes the collision between the Star Destroyer and the Lightmaker (Hammerhead corvette) in terms reminiscent of momentum interactions:

Raddus watched the Lightmaker descend like a spear into the mass of the disabled behemoth. Metal sheared and crumpled, and Raddus feared for a moment that Oquoné's velocity had been too great — that the Lightmaker would be dashed to nothingness and the most delicate part of the plan, still to come, had failed. Yet the Destroyer absorbed the impact and began to tumble away, its frame marred but intact.

Rogue One: A Star Wars Story - Official Novelization Chapter 20

Presumably the momentum transfer of the Lightmaker was enough to push the Star Destroyer past a point where its engines could provide enough power to keep it aloft.

7
  • Huh? the star destroyers are in orbit they will stay there for effectively forever with no power. en.wikipedia.org/wiki/Space_debris
    – Sam
    Dec 27, 2016 at 18:15
  • 1
    @Sam They don't act like they're in orbit -- they stay over the same spot on the planet for half an hour or so. If they were in orbit round an Earth-like planet they'd be a third of the way round the planet by then. They're hovering, which needs continuous expenditure of energy unless you're in a much higher geosynchronous orbit.
    – Mike Scott
    Dec 27, 2016 at 19:10
  • @MikeScott See my answer to this question: "Knowing the orbital parameters of Scarif is impossible. If it had similar density, rotation rate, and size to earth a synchronous orbit would be impossible at that altitude and the ships indeed would need huge amounts of power to maintain their position, but there is no reason to believe any of these things are the same or even similar."
    – Sam
    Dec 27, 2016 at 19:28
  • @Sam All the fewer reasons to believe the ships are in orbit.
    – void_ptr
    Dec 27, 2016 at 21:46
  • @Sam If you're looking for realistic depictions of physics, what are you doing watching Star Wars? Dec 28, 2016 at 14:04
2

Knowing the orbital parameters of Scarif is impossible. If it had similar density, rotation rate, and size to earth a synchronous orbit would be impossible at that altitude and the ships indeed would need huge amounts of power to maintain their position, but there is no reason to believe any of these things are the same or even similar.

To push something out of orbit that fast would require a huge amount of force (in Earth Human terms), and as you should know F = MA, so we would need to know the acceleration provided by the engines on the hammerhead, and the mass of the combined system. Both are probably very difficult to find canon sources for.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.