system
Given the following post, respond as if you're commenting on Reddit:
human
Why is a fast reentry from space back to earth a better option than a slow decent?

I've always wondered why the SOP for reentry into Earth is a fast decent when it requires a incredibly important heat shield on the shuttle, and if said heat shield is damages then the astronauts lives are is danger. I'm guessing that the reason the heat shield is needed is because of the friction with the atmosphere at high speeds during reentry is causing it, so I wonder why a slow decent isn't better than a fast one.
gpt
Well, two issues, spacecraft in orbit are already moving at orbital speed, which is 7.8 KPS for LEO, and varies depending on the orbit. So, that speed has to be scrubbed in order for the spacecraft to intersect the surface at nearly zero velocity, otherwise, its a crash. The most efficient way to scrub that speed is by friction with the air. A powered descent (Like the Apollo LEM) is possible, but that would require lifting massive amounts of fuel into orbit to make it happen, which means much larger rockets for launch, etc...