The final U.S. Space Shuttle flight is scheduled for Friday, but according to NASA, weather may delay Atlantis' final mission a day or two.
Whether or not the shuttle takes off on schedule, the impact of that day will forever mark the end of an era for Univeristy of North Texas' Astronomy Program Director Ron DiIulio.
Fascinated by space as a child, Dilulio's nickname -- Star Man -- is a perfect fit.
"We all wanted to be space persons," said DiIulio.
He began chronicling the space program by collecting autographed, commemorative envelopes and stamps. Each object in his collection represents a moment in space history.
"I'd find out when they were going to do a test on a new rocket or the escape module for the crew, and I'd send an envelope and ask if they would put a cache, and it would say 'First test of the engine'. And they would send that back to you," said DiIulio.
His collection dates back half a century, and DiIulio said it's the attention he paid to the space shuttle program that sticks out the most.
"The plan was just to use it as a truck to build a space station, and it has lasted much longer than that. It's a 30 year old mission with 40 year old technology," he said. "This is probably the largest collection of shuttle memorabilia in the world."
There are 2,000 to 3,000 commemorative envelopes in DiIulio's collection. Even in this large collection, he has a few favorites.
"They are my favorites because they show how far we have come in just 50 years," said DiIulio.
He said the final shuttle launch completes just part of the story, and it's his mission to document it all.
"The shuttle is the body of the novel, but we have to have other chapters," said DiIulio.