While an object in motion tends to stay in motion - it only does so until subjected to an opposing force. In this case, that opposing force is Earth's gravity, and all a "little propellant" buys you is a slightly higher orbit.
Gravity will not bring it down, not for millions of years. Collisions with molecules in the fringes of the atmosphere are the opposing force.
When you look for a periodicity in a bunch of data, you might do a fourier transform and look for peaks. (The other work did that.) Essentially you're doing a large number of correlations. If you try 100 corelations, you should not be surprised to see one that's significant at the 99% level, just by chance!
On the other hand, if the periodicity they found matched known astronomical phenomena (as opposed to the other work I looked at), the probability of a chance result is much reduced.
Doubt isn't the opposite of faith; it is an element of faith. - Paul Tillich, German theologian and historian
