I’m done building the first stage of the rocket, sort of. When I picked it up to admire my handiwork, I thought I felt something move, and it wasn’t the earth. So I, very carefully, shook my creation, very lightly. I figured that’s what they would do at Cape Canaveral, though, while my model weighs 5.5 pounds, an empty Saturn V weighs about 188,000 kilograms. In pounds, that translates to really, really heavy, so maybe the real engineers use different methods to check things out.

Anyway, I heard a tiny clatter, clearly caused by gremlins (see The Twilight Zones’ Nightmare at 20,000 Feet episode), which sounded like it might be emanating from a small, loose piece floating about somewhere in the bowels of the cylinder (much like the cartilage in my knees), with no way to extricate it short of disassembling the entire thing (much like my knees).

If I were a surgeon who accidentally left something clattering around inside a patient, it would be called a retained object and I’d get sued for malpractice. According to a 2013 letter on the Public Citizen website, the estimated number of objects left behind after surgery each year ranges anywhere between 1 in every 1,000 and 1 in every 18,000 surgeries. Ouch.

I couldn’t find any statistics related to objects left inside rockets. However, I did discover that one can buy rocket insurance to protect against damage or injury to the person or property of another or failure of a launch. Good to know.