— Fifty years to the day after its chronograph became the first and only "unauthorized timepiece" to be worn by an astronaut on the surface of the moon, Bulova is launching a golden replica of its infamous watch.

Bulova's 50th Anniversary Lunar Pilot is styled after the prototype chronograph that Apollo 15 commander David Scott secretly flew and wore for his third and final moonwalk on Aug. 2, 1971. The design of the original watch was never put into production, but a replica was introduced in 2016, after Scott sold his moon-flown artifact for $1.6 million at auction.

The 50th anniversary model, which is a limited edition of 5,000 pieces, builds off the design of the astronaut's watch and the first Lunar Pilot replica by adding a special 45mm titanium case and celebratory gold-tone accents and pushers. The $995 watch is individually numbered on its caseback, which is further inscribed "Apollo 15 50th Anniversary, EVA-3 Aug. 2, 1971" and features a depiction of an Apollo astronaut on the moon.

"Bulova has a rich history with NASA, having participated in 46 space missions, including the Apollo 15 mission in 1971," a Bulova spokesperson wrote in an email to collectSPACE. "Apollo 15's mission commander, who is also the seventh man to walk on the moon and the first to drive the lunar rover, made history while wearing his personally-gifted Bulova chronograph."

"To celebrate this moment, Bulova is releasing the 50th Anniversary Lunar Pilot Limited Edition timepiece," she wrote.

Apollo 15 launched on July 26, 1971, with Scott, command module pilot Al Worden and lunar module pilot Jim Irwin on the fourth mission to land astronauts on the moon. In addition to being the first to include the Apollo Lunar Roving Vehicle (LRV), which allowed Scott and Irwin to cover a much greater distance than prior missions, Apollo 15 also set records for the longest time spent on the lunar surface and for the first deep-space extravehicular activity (EVA).

Like all of NASA's moon-bound astronauts, Scott was issued an Omega chronograph to use while on Apollo 15. He wore the Speedmaster for his first two moonwalks but sometime during his second excursion, the crystal that covered the watch's face popped off and was lost.

Known only to a few people at the time, Scott had packed the Bulova prototype (and a Bulova stopwatch) after being approached by the watchmaker to privately evaluate the timepieces on his flight to the moon. With his Omega broken, Scott retrieved the Bulova from his personal items and wore it for his final moonwalk. He then continued to wear the timepiece, up to and through his splashdown on Earth.

As part of a post-flight investigation focused on other items that were carried on Apollo 15, NASA labeled the Bulova chronograph as an "unauthorized timepiece" and withheld releasing the brand name to avoid it being commercialized. (As it happened, the make and model of the watch was widely misattributed until 2015, when Scott put the flown artifact up for auction, confirming that it was a Bulova.)

Like the first Lunar Pilot released five years ago, the 50th anniversary limited edition features a high-performance quartz movement and is water resistant down to 50 meters (165 feet). The new model comes with a supple grey leather NATO strap and has a blue sapphire crystal with AR (antireflective) coating.

The 50th Anniversary Lunar Pilot watch is now available through Bulova's website.