That signature piece was the spacecraft ID plate from Eagle, the Apollo 11 lunar module. It was the auction item that brought the most money from the collection once owned by Armstrong, the first man to walk on the Moon.

The spacecraft ID plate was one of three Lunar Module-5 Identification Plates that went to the Moon with Armstrong, Buzz Aldrin, and Michael Collins on their July 1969 mission. When the men returned, their were each given a plaque on which was affixed one of the plates.

The Armstrong ID plate was part of the three-day Space Collection Signature Auction, put on by Dallas's Heritage Auctions. The entire sale brought in $7.4 million, the auction house said, with $5.2 million of that being paid for Armstrong items.

Three other items that Armstrong took to the Moon with him sold for $275,000 each:

• a larger-than-normal U.S. flag
• a medal honoring the Apollo 1 astronauts who died a launchpad fire
• a piece of the Wright Flyer, used by Wilbur and Orville Wright at Kitty Hawk.

Also selling were the flight suit that Armstrong wore on the Gemini 8 mission, which brought in $109,375, and a crayon drawing of flowers that he did for his mother, which sold for $15,000.

It wasn't just Armstrong memorabilia on sale: A helmet worn John Glenn, the first American to orbit Earth, went for $46,250. Glenn worn the golden helmet while setting the transcontinental speed ruing in 1957.

The auction house said that it was planning two more auctions of Armstrong items, one in May 2019 and the other in November 2019.

Armstrong died in 2012.