So most astronauts are astronauts for a couple of years before they are assigned to a flight.
The majority of astronauts have to change their eyeglasses while in space. They bring eyeglasses with them and typically change a few months into the mission.
Our focus is to get citizen astronauts to experience the 'overview effect,' return to Earth, and then impact their communities.
I was only a hero by default. The flights were few and far between. There weren't that many astronauts. The moon flights were so interesting and exciting.
Astronauts working for the government will always need to be either pilots or mission specialists. Those who want to be pilots should have military experience - ideally, a test pilot background.
I'm Chinese-American, of course, and so it's very interesting to see China actually launch their own astronauts, becoming the third nation, following the United States and Russia, to do so.
Two months after I got out of test pilot school, I saw an advert that said NASA was recruiting more astronauts. The best job you could have as a test pilot was being an astronaut, so I volunteered.
NASA has never had a problem finding capable people to be astronauts. NASA's problem was, and still is, finding ways to cut the list of capable applicants down to a manageable length.
Mars missions will require up to three years in reduced gravity, so we need to make sure astronauts can not only survive but thrive as they move outward to explore this new world.
Manned spaceflight has lost its glamour - understandably so, because it hardly seems inspiring, 40 years after Apollo, for astronauts merely to circle the Earth in the space shuttle and the International Space Station.
In 1960-61, a small group of female pilots went through many of the same medical tests as the Mercury astronauts and scored very well on them - in fact, better than some of the astronauts did.
The successful golfers - they're like astronauts or pilots. They have that demeanor that they can focus and stay within that one moment and nothing distracts them. That's not me.
I'm honored to be recognized among generations of astronauts who were at the forefront of exploring our universe for the benefit of humankind.
Astronauts have been stuck in low-Earth orbit, boldly going nowhere. American attempts to kick-start a new phase of lunar exploration have stalled amid the realisation that NASA's budget is too small for the job.
I remember growing up thinking that astronauts and their job was the coolest thing you could possibly do... But I absolutely couldn't identify with the people who were astronauts. I thought they were movie stars.
Funding for the original manned Voyager Mars Program was scratched in 1968, before humans had gotten out of Low Earth Orbit. Mid-'60s plans for a Venus fly-by with astronauts actually flying by it met the same fate.
