How does gravity work on the Icarus?

Question

Sunshine doesn't strike me as the most scientifically inaccurate film, and how it deals with gravity has caught my attention. The Icarus (I & II) seems to have long cylindrical compartments, with earth-like gravity in a single arbitrary direction. Is the way gravity works in Sunshine ever explained (any solid theories)?

Also: One scene particularly gets to me. About 1 hour and 30 minutes in, when Capa is in his golden suit. There is a part where he trips. After slamming into the floor, it seems gravity is enhanced, as by a burst of acceleration. You can see his saliva being pulled towards the floor for a few seconds. He then gets up and seems fine. What is going on here?!

Answer 1

One of the film's deleted scenes explained this. The original plan was to have the gravity provided by the payload itself, a blob of compressed dark matter the same weight as the moon. In the end this plot point seems to have presented the writers with more problems than it solved and they just chopped it out in favour of the ship having inexplicable gravity.

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From a screenwriting perspective, the films's 'Senior Science Consultant'; Professor Brian Cox addressed this point in an interview with Sci-Fi Online magazine.

Bluntly, they don't attempt to explain it. He handwaves it with the classic "It's just a movie" explanation for bad writing.

It's very interesting. These guys that get really pedantic are really, I think, missing the point about what science is all about. It's about precision, when you're doing it. So when you're doing research it's all about precision and attention to detail and that's the difficult bit, and that's what you learn how to do. But deciding what research field you want to do, and having really good ideas about what to go and measure, and what to try and find out, that's a creative process. I think a lot of the pedants kinda miss that.

Like you say, Sunshine is not a documentary. It's trying to just, in an hour and forty minutes, get across a feeling of what it's like - not only to be a scientist, because obviously there's much more in it than that. So, I found it interesting to watch the kind of people that get upset because the gravity is wrong.

Answer 2

Icarus's gravity isn't explained in the film but we must assume some sort of artificial gravity generator other than spinning crew compartments, otherwise the mission isn't survivable. The problem is their flight path and the Sun's gravity.

A mission simulation was shown around 22 minutes into the film.

We see Icarus drive straight toward the sun just as they would on Star Trek. No futzing around with transfer orbits, they just go straight in like a skydiver, release the bomb, and accelerate straight away from the Sun. Four minutes later the bomb fires its engines and dives into the Sun. The problem with such an aggressive flight plan is that near its surface the Sun's gravity is 27 times that of Earth. Without an artificial gravity source to negate that force, just holding station above the Sun will crush everyone aboard Icarus into paste and likely pancake the spindly-looking ship against the thrust of the engines.

The only way the mission works without artificial gravity is if Icarus does a burn to inject itself into a hyperbolic or elliptic trajectory that is a close flyby of the Sun. At perihelion Icarus separates from the bomb, which does a final burn to plunge into the Sun, while Icarus coasts along the outward leg of the orbit away from the Sun. Icarus would be in free fall throughout the close part of the flyby, so the Sun's high gravity would not be a hazard.