Apollo 11 Spacecraft Handle. The only flown external handle from the Apollo program
And it's the only part of the Apollo 11 Command Module outside of the Smithsonian. All of the other exterior spacewalk handles were destroyed as nuclear waste. Why? The glow-in-the-dark discs that allowed the astronauts to find the handle in the dark. But, these are no ordinary discs. They used to glow brightly thanks to some refined nuclear waste inside. A crack in one of these discs delayed the Apollo 10 launch. The concern, post-flight, was that the radioactive material could pose a risk to the public... if the discs cracked... and a visitor ingested the radioactive leakage somehow. So the handles on Columbia in the Smithsonian are replicas, minus the radioactive discs.
But a JSC vet with experience with radiological elements was not so afraid of the Promethium 147 in each of the four discs, and he offered to study the degradation of the discs for 20 years at his expense, if he could keep the handle in exchange. That was the contract with Chris Kraft of NASA. All of the other handles went to a nuclear waste dump supervised by the U.S. Nuclear Regulatory Commission. With a half-life of 2.5 years, the discs are 250,000x less potent as they were in 1969 but they still glow continuously in a dark room (as I tested in our bathroom at work).
When this artifact came up for auction in 2000, David Herskowitz, Butterfields' natural history specialist summarized: “In my opinion, it is the only legitimate Apollo 11 artifact that has been offered to the public."