This is a common misconception of many people.

Many people believe any object that goes from "space" to "earth" must inevitably do so dramatically as a "fireball" when the object hits the atmosphere.

This misconception is perfectly understandable given the fire-ball reentries we often see of space capsules and space shuttles!

But essentially, the only reason that SOME objects hitting Earth's atmosphere "burn up" in a huge dramatic fireball is simply due to speed. Nothing else. Just speed.

So the fireball effect depends entirely upon the speed of the object going from "space" to "earth".

Objects in space can move really (really) fast because there is no air resistance when the object is in space.

So when the space shuttle, or a space-capsule, or a piece of space junk, or an old satelite, or a meteor hit the atmosphere for re-entry, they are usually travelling very fast, at around 18,000 mph (for most spacecraft), to upwards of 66,000 mph (for meteors) or sometimes even faster.

So you can imagine when an object going at such a high speed hits the atmosphere it's one incredible light show and huge fireball, generated by friction with the atmosphere.

In fact some small particles streaming from our sun (or more distant stars), slam into Earth's atmosphere at nearly the speed of light, and generate insane high temperatures at that tiny microscopic point of impact, for a fraction of a second.

Interesting Tangent:

Astronauts in the Apollo space program reported seeing a constant "flickering" and "sparkling" of white light whenever they closed their eyes to sleep in space, or on the moon. The flickering was actually tiny particles from the sun, and stars, slamming into their optic nerve at nearly the speed of light.

Fortunately Earth's magnetic field diverts most of those particles... so we don't see them when we close our eyes. But if Earth's magnetic suddenly turned off, that's the first thing everyone on Earth would notice. Everyone would be saying, "WTF is that white sparkling light whenever I close my eyes?!"

But back to the issue of speed:

Similarly, here on the surface of Earth, if we could suddenly launch an object (like, say a bullet) at 18,000 mph, it would also travel in a very visible fireball-effect through the atmosphere, near the surface.

(The friction of this "bullet" with the air, would likely vaporize it pretty quickly, or turn it into a small cloud of dust, so it probably wouldn't get very far.)

NOTE:

When NASA launches a rocket or space shuttle upwards, towards space, it is obviously not yet going at 18,000 mph while it is in the lower atmosphere. But by the time it gets over the atmosphere (or at the very "thin" part of the atmosphere) that's usually when they go for "throttle up" or activate an additional booster-stage rocket.

Once those booster rockets kick-in (or they go for throttle up) with virtually no air resistence, that's when that puppy really accelerates beyond human imagination and quickly hits upwards of 18,000 mph!

(It's some serious insane acceleration when a booster-rocket kicks, or they go for "throttle up" above earth's atmosphere! Imagine the fastest you've ever seen a car rev it's engine and accelerate, and multiply that by many many factors... and you can begin to imagine how that must look/feel.)

Conversely, if you are up in space, going at a LOW speed, and you let yourself "float downward", then you WILL NOT burn up in a fireball. Why not?

Because: in that scenario you are not going very fast.

Your fastest speed if you "gently" let yourself float downward, might be somewhere around 1000 to 2000 mph at the upper atmosphere... not enough to burn up... and when you begin hitting the lower atmosphere, your speed is probably somewhere "only" between 250 to 500 MPH.