system
Given the following post, respond as if you're commenting on Reddit:
human
[Halo] How can Spartans survive a fall from space but can be killed by normal bullets?
gpt
A Spartan coming out of atmospheric reentry is traveling at subsonic speeds. Spartans have reinforced skeletons. The impact is distributed over their entire body. Mjollnir armor has a distributed pressurized gel system for medical purposes which can be repurposed as an impact cushion. Statistically speaking, Spartan atmospheric and quasi-atmospheric reentry has a greater than 50% injury rate, and a 100% chance of moderate to major materiel failure.

A bullet, on the other hand, travels at supersonic speeds and concentrates all of its force on a small point. ~~All recorded one-shot kills on armored Spartans were high-caliber armor-piercing rounds to the head.~~ An armored Spartan can be killed in one shot by a high-caliber armor-piercing round to the head.

You do the math.