This month marks the 45th anniversary of Apollo 11 landing on the moon. One thing Moon Hoaxers loved to point to you as evidence that we didn't actually go to the moon is the flags. They all appear to be waving in the non-existent wind on the lunar surface. Well, the landings weren't faked and the flags aren't blowing in a mystery wind. They were just expertly engineered by NASA scientists. The question of how to erect an American flag at Apollo 11's landing site was raised about three months before the mission launched. And the problem of having no wind and atmosphere to support the flag was quickly solved by adding a crossbar to the top of the flag. Soan into the fabric the flag would hang rather than blow in the breeze. But building a rig that astronauts could deploy while wearing bulky pressure suits on the lunar surface was a bigger challenge. One that took a team of engineers to solve. The final flag design assembly was a lightweight and compact design that weighed 9 pounds and 7 ounces and could be folded for easy storage. It used a two-part telescope pole apparatus with a telescope crossbar, an easy design to deploy on the moon with gloves on. Once both poles were extended, a catch prevented the horizontal bar from falling. The upper portion of the vertical pole was slipped into the lower part that the astronaut would have already hammered 18 inches into the ground. The flag assembly was stored outside the spacecraft. On the left hand side of the lunar module's ladder, a decision that came with its own challenges. This placement exposed the flag to the keep generated by the lunar module's descend engines. Enjoy the terminal touchdown phase? The ladder was expected to heat up to 2,000 degrees Fahrenheit. The anticipated heating demanded a specialized protective shroud be added to the flag assembly. The final casing was a stainless steel outer case separated from an aluminum casing by a layer of thermoflex insulation. Multiple layers of a thermal blanketing between the shroud and the flag gave it further insulation. It wouldn't get any hotter than 180 degrees Fahrenheit. Six American flags replaced on the moon surface during the Apollo lunar landing program, but only five are still standing. Neil Armstrong and Buzz Aldrin put theirs a little too close to the lunar module. When they fired the ascent engine and left the lunar surface, the exhaust knocked the flag right over. Want to relive the excitement of Apollo 11? I'll be doing a live tweet this month starting on launch day July 16th. And for weekly vented space updates, don't forget to subscribe.