Remnants of China's largest rocket launched last week are expected to plunge back through the atmosphere — dropping the equivalent of three pickup trucks or a small plane late Saturday or early Sunday, an expert said. Long March 5B, the Chinese rocket, is equivalent in size to an unloaded semi-truck and weighs roughly 22 tons — as much as nine tons of material — and is expected to survive, Ted Muelhaupt, principal director of The Center for Orbital and Reentry Debris Studies (Cords) at the Aerospace Corporation, said.