Discovery Channel, known for its interest in all things scientific has signed Natasha Stillwell (Daily Planet) to Break It Down. Stillwell and compatriots will look at such icky topics as what happens after we flush, to sticky topics like what happens when our road systems can no longer handle the amount of traffic fed into them. The team also looks behind the scenes at a junkyard, movie stunts, landfills and elevators. This six-part series, produced in HD, premiers Tuesday, May 2 at 8 p.m.