The fiscal 2021 budget would eliminate the $120 million that NASA’s Office of STEM Engagement, which provides a range of educational opportunities from informal programs at museums to grants at colleges, received in fiscal 2020. But it would boost the exploration budget by 46 percent to send humans back to the moon by 2024 -- as a stepping stone for a mission to Mars.

“If you don’t give a kid some rationale for the importance of it, they’ll say why should I study STEM? Where is that going to lead?,” said Gregory, a retired Air Force colonel. “If you can’t answer that question … then the kid decides to do something else.”

He also spoke about his take on NASA's moon plans and how to increase diversity in the astronaut corps.

"We should not establish some kind of quota," he contends.

This transcript has been edited for length and clarity.

What do you think of NASA’s plans to go to the moon and then Mars?

I think the nation should do things they thought were impossible yesterday. If we have done it once before, it would be a side trip for me, not the principal motivator.

Does that mean you aren’t a fan of the administration’s lunar plans?

I’d hate to be characterized like that. NASA is a research and development organization. They’re the ones who come up with concepts and develop it into something that has minimal risk that can then be handed off to industry to continue. We’ve done the International Space Station, and we’re good at it. … So let private industry continue that. Let NASA do things that are scary and risky, like going to the moon or developing something that excites the population so the community goes to the government and says, “Look, these are the kinds of things we would like to do in the future.”

Why should a kid study STEM? If you don’t give a kid some rationale for the importance of it, they’ll say why should I study STEM? Where is that going to lead? … If you can’t answer that question … then the kid decides to do something else. ... I’m not talking about women, blacks, green or purple people. I’m talking about all kids. That’s how you create a pool of excited people who are interested in doing things. When you do that, you end up with a very diverse pool.

What do you think of NASA’s fiscal 2021 budget request cutting STEM programs?

Education I think is very important. When I was deputy administrator, I thought education was an essential part of the role that NASA would have to encourage students. But when you look at what NASA wants to do and look at the budget they have, because of their limited budget, they have to make choices. … I think they are making the correct decision. I just wish that instead of $25 billion, their budget was $100 billion. Then we could do anything, as we did in the early ‘60s to get a human on the moon within the decade.

How did you become interested in space?

When I was about 5 or 6 years old, my family had friends who were pilots. I would sit at their feet and listen to them talk about flying in combat. These were combat pilots who flew escort for bombers going into Nazi-controlled Europe. One offered to take me for a ride when I was about 5 or 6. My dad said yes, but my mom was the sane one in the house and she said no, so my first airplane ride was a taxi around the runway as opposed to an actual flight.

I had this great interest in airplanes at a very early age. … I decided I wanted to go to this school they were building in Colorado, the Air Force Academy. ... I was in my mid-30s when I first had any interest in applying [for the astronaut program.] I had a couple people who influenced me to apply. … The folks who were friends with my parents, the pilots, it turns out they were all Tuskegee Airmen. One of them called me and said you need to apply for that program for yourself and for the Tuskegee Airmen. … They were the influencers in my life who encouraged me to do things that most people had not done before.

What was your experience as the first African American shuttle pilot?

We talk about being the first to do something or that we need women or blacks or Jews. … I would hope we evolve from that and become citizens of America or of the world who are doing these great things. We should not establish some kind of quota that is necessary for the things we do in the future. That is a general challenge to the question you just asked me.

Motivation comes from within. Instead of being sought out, you have to be the one that drives becoming a part of something. … It’s the same thing when you begin to look at things like where the world should be going into the future. ...Instead of the government telling us what we should do, we should demand that the government do these things. In my case, people should go up and say 'we’d like to go to Mars because we’ve never been there.' I know it's scary and risky and costs a lot, but it’s really important for us because it influences the next generation.

We want them to be competent in engineering and science, but unless you give them a vision to shoot for, you will always have this issue of not having enough people. We should be trying to develop a workforce or pool of people who are so qualified and so anxious to become part of this program that they come and demand that they be part of the program.

Applications for the next class of astronauts are about to open. Any advice?

I have already had a couple dozen people ask that same question. … The first thing I tell them is, if you are considering it, go ahead and apply. That’s my advice.

What was your reaction when you found out you had been accepted?

I interviewed and heard nothing at all. Then I was coming into the school one morning in mid-January and there was a little note in my mailbox that said to call George Abbey [the former director of the Johnson Space Center.] He asked if I was still interested in this job. I was in total shock. I was stammering. It was at 7:30 a.m. and he told me that I couldn’t tell anyone until noon because there was going to be a press release. I kept the secret for about five minutes.