How much reserve fuel does an out of service satellite need to use after it burns up in Earth's atmosphere? How much fuel do you imagine it takes a satellite t

How much reserve fuel does an out of service satellite need to use after it burns up in Earth's atmosphere? How much fuel do you imagine it takes a satellite to re-enter if it will happen automatically in a matter of a few years? The answer to both is, of course, not much, not much at all.