As an astronaut, she's "been there," but never "done that." No woman has, reports CBS News Correspondent Jim Axelrod.
"It's been a long time coming to have a woman commander of any space mission," Collins says.
She's a 42-year-old Air Force colonel with years of training and 400 hours in space. NASA's given her command of the shuttle Columbia on a mission that will launch a $1.5 billion space telescope.
Collins tries not to think too much about her historic role. But she admits, "there is added pressure without a doubt."
Since NASA's earliest days, the final frontier has been dominated by men. Of the 242 people who've flown in U.S. spacecrafts, just 31 have been women. As the great space pioneer John Glenn once put it, "women are not astronauts, that's the way of life."
Gerry Truhill was one of 13 women tested during NASA's Mercury years, but couldn't join the boys and fly in space. For her, Collins' mission is a very big deal.
"She has really carried our dreams right up there where we wanted them," Truhill says. "It's too late for us but not too late for our granddaughters."
Collins feels that "I can be a role model for those young girls. I didn't have a role model when I was 9 years old. I would like them to have a role model. I would like them to know they can do whatever they want to do."
The Columbia is set to lift off a week from Tuesday, on the 30th anniversary of Apollo 11's flight to the moon. A not-so-small step for one woman about to smash perhaps the highest-altitude glass ceiling so far.