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Comment by Mister_Snuggles | Hacker News Reader

I'm really surprised by this oversight as other things (magnetic boots) from The Expanse were explicitly mentioned.

In The Expanse, this is exactly how ships are set up. The "floor" is towards the engine and the continuous 1g acceleration provides "gravity". When a ship starts decelerating there is a "flip and burn" where everyone straps in while the ship literally turns around and starts accelerating at 1g in the opposite direction (meaning it's slowing down relative to its destination).

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Most ships in The Expanse travel under much lower (1/6-1/2 G) accelerations because they didn't magic away all fuel consumption just made the fusion drives fantastically efficient. As you get to poorer ships more time is spent "on the float" between target and destination. Even our main character's ship doesn't accelerate all the time while travelling.

From what I remember, not just more efficient but also a LOT more thrust than realistic.

> In The Expanse, this is exactly how ships are set up. The "floor" is towards the engine

This is pretty common in written science fiction but the fact that it is uncommon in movie/tv sci-fi is pretty damning really. Having spacecraft fly around like aircraft or cruise like ships, with decks "horizontal" and engines at the "back end" is just so bloody stupid. If you can't get basic physics right you have no business making science fiction. /rant

It could just flip much more slowly and maintain ~1g, with minimal course correction.

Presumably the mid-point is where the ship would be travelling at maximum velocity, so the course correction may not be as minimal depending on how slowly we're talking. It might be this would use more fuel/mass.

There's no such thing as maximum velocity. If constant 1g acceleration is available, there's not really a fuel concern. It will certainly use a little more fuel, but even just going to Mars would take a week, so half an hour's extra fuel usage works out to 0.3% extra fuel. For interstellar journeys, you're talking less than 0.001%.

Also, the course correction can easily be part of the manoeuvre, if you're willing to rotate around more than one axis.

Yeah, I could imagine some spiraling maneuver that would rotate 180° while maintaining constant acceleration. However, a flip and burn would certainly be more efficient (no cosine losses).

As well as strapping in to gel couches before high G maneuvers, the crew also connected themselves to IVs for auto injection of anti-clotting drugs so they could minimize the chance of a stroke or aneurysm.

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