Emergency braking in space

The phrase "raspberry jam delta-v" comes to mind.

Also, the obligatory clip from Spaceballs...

https://www.youtube.com/watch?v=NAWL8ejf2nM

I wonder what sort of spaceship would be capable of emergency deceleration at 4g for nine days, but would choose a leisurely 0.1g cruise to get up to .1c over the course of over a year instead.

edit: actually, what sort of rotational rings would withstand that 4g load? Surely they'd break apart.

I guess that might be part of the fun and exciting plot - the rush to move vital equipment into the core of the ship, and choosing to abandon the rings, and adapt to a week of high-g, followed by a long low-g cruise period.

> Can humans withstand 4 g non-stop for 9 days?

They might if you keep rotating them, so the force is not along one axis all the time.

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).

The relativistic rocket calculator linked in the comments is quite interesting.

https://gregsspacecalculations.blogspot.com/p/blog-page.html...