A sterling silver Apollo 11 Robbins medal belonging to astronaut Dave Scott is set to lead a sale at RR Auction that closes on April 15.
Bidding stands at $8,100.
Robbins medals were regularly flown aboard the various shuttles and rockets and presented to astronauts and crew as mementos.
They are among the most desirable items of space memorabilia, having grown substantially in value in recent years (Apollo 11 examples are up 9.6% per annum between 2004 and 2014).
It's accompanied by a letter of provenance from Scott that reads: "I hereby certify that the Apollo 11 silver medallion number '190' included with this letter is from my personal collection and was flown aboard Apollo 11, July 16-24, 1969…
"After the mission, the Astronaut Office distributed the medallions accordingly. I specifically requested the Apollo 11 number '190' included with this letter."
Other lots from Scott's personal collection include an Apollo 15 mission patch, which is at $3,328.
He writes: "The Apollo 15 patch (with silver 'XV') included with this letter was carried to the surface of the Moon aboard the Lunar Module Falcon 'Falcon' during Apollo 15…
"Jim Irwin and I landed the lunar module 'Falcon' on the Moon between Hadley Rille and the Apennine Mountains…This special Apollo 15 patch has been in my personal collection since returning to Earth."
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