BOSTON, MASS.- The auction will open with an unprecedented selection of rare 18K gold Omega chronographs presented to the pioneering astronauts of the 1960s. Omega initially created 26 of these gold commemorative watches—known as the 'Tribute to Astronauts' watch—to present to NASA astronauts alive and deceased, with the case back of each watch specially engraved with a quote, the name and missions of the astronaut, and a unique number relative to when the astronaut flew into space.

The top lot is the Omega Speedmaster awarded to the late Gus Grissom, commander of Gemini III, whose family had accepted the 18-karat gold timepiece at a dinner in Houston, Texas, in November 1969. What sets this trio of Omega watches apart is that it might be the lowest-numbered example ever to reach the market, following behind Nixon and Agnew's pieces with estimates suggesting it could fetch over $350,000.

“Grissom's Speedmaster is a stunning timepiece that honors an astronaut who paid the ultimate sacrifice for the American space program, says Bobby Livingston, Executive VP at RR Auctions.

Alan Bean, the fourth person to walk on the moon via Apollo 12, was in quarantine at the time and received the watch later on. (Estimate: $200,000+) Ron Evans, who was part of Apollo 17's space crew, was presented with a Speedmaster with a new set of numbers not part of the original 28 examples. (Estimate: $100,000+)

Another key piece offered for sale is Gene Cernan's Apollo 17 EVA-1 cuff checklist, smeared in moon dust from its use for seven hours in the lunar environment. The cuff checklist was carried and used extensively on the lunar surface during the first extravehicular activity of the last Apollo moon mission. Cernan wore this cuff checklist on his wrist for the duration of the first EVA of Apollo 17, exposing it to the lunar environment for 7 hours and 12 minutes—as such, its pages are still streaked with lunar dust. (Estimate: $500,000+)

Further remarkable items include Apollo spacecraft hardware—such as a DSKY computer interface and a Lunar Module hatch—a multitude of flown checklist pages, flags, and Robbins medallions from the collections of astronauts, and a stunning assortment of meteorites.

The Space Exploration and Aviation auction from RR Auction will conclude on April 20.