Part of the challenge was that the time of the opening kept changing. Originally, the museum was scheduled to open on July 4 as a birthday gift to the nation, but it was felt that it would compete with other bicentennial celebrations, and besides, the museum was ready to open.

Then there was the lander at Mars.

Viking 1 was supposed to land on July 4, but when it arrived in its certification orbit two weeks earlier, imagery of the primary landing site showed its terrain was too rough to guarantee a safe landing. NASA delayed the landing to July 20 as a more suitable landing site was sought.

So Collins was already dealing with date and time changes beyond his control.

“But believe it or not, all of the electrons did their cute little things and the ribbon got snipped and the building got opened. It was good,” he said.

The doors then opened, and the public got their first look at the Wright brothers’ 1903 Flyer, Charles Lindbergh’s Spirit of St. Louis, and NASA space capsules, including the command module Columbia that Collins flew to the moon in 1969.

Of course, NASA and the Smithsonian were not going to allow a wayward signal to ruin the day. There was always a backup plan.

“We were prepared to cheat,” said Don Lopez, who was a member of the museum’s original staff and later its deputy director before his death in 2008. “We had a guy in the back with a button to push if it didn’t happen.”

A mystery 50 years in the making

With the ribbon cutting a success, contemporary reports suggest NASA packed up the sampler and took it back with them.

So what became of that arm?

Inside the museum on July 1, 1976, Viking was represented by a static model that had previously been in the US pavilion at the 1975 Paris Air Show and then was on display in the “Life in the Universe?” gallery.