For the latest in our "Ask an Expert" series, current NASA astronaut Donald Pettit and former astronaut Jeffrey Hoffman chat about their spaceflight experiences. From brushing your teeth to weightless dreams, the astronauts discuss the many curiosities of living in space.
Copyright NPR. View this article on npr.org.
IRA FLATOW, HOST:
Next up, who didn't, at one time or another, now think about it, who didn't want to be an astronaut when they were growing up, especially those of us, the children of the space-age space race? Well, for those of us whose lives are a bit more Earthbound, we've got a fun edition to our Ask an Expert series. How about Ask an Astronaut? Everything you wanted to ever ask an astronaut, Flora.
FLORA LICHTMAN, BYLINE: That's right. Get those dialing fingers ready everybody. Get your tweets loaded because if you had the chance to ask - you have that chance, to ask an astronaut anything you want, but the calls are screened.
FLATOW: Up to a certain extent.
LICHTMAN: Up to a certain extent, that's right. So we've got two space travelers on the line to answer your questions, 1-800-989-8255, 1-800-989-TALK. If you're on Twitter, tweet us @scifri.
FLATOW: And our astronauts this hour, or returning champions as they might say, Don Pettit is a NASA astronaut who spent more than 350 days in orbit. Just this past July, he returned to Earth after spending six and a half months aboard the International Space Station. I have questions already going through my mind. He's joining us by phone from the Johnson Space Center in Houston. Welcome back.
DON PETTIT: Ira, it's really good to be on your program, and it's good to hear Flora's voice, as well.
LICHTMAN: Thanks, Don, glad to have you back.
PETTIT: You're usually in the backdrops, pulling all the strings that make Ira operate.
LICHTMAN: Ira let me sneak in today.
FLATOW: We're looking behind the curtain today.
LICHTMAN: We also have Jeffrey Hoffman. He's a NASA astronaut for almost 20 years, and during that time he flew in space five times, including once to repair the Hubble Space Telescope. He's now a professor in the Department of Aeronautics and Astronautics at the Massachusetts Institute of Technology, at MIT. Welcome back to the program, Dr. Hoffman.
FLATOW: Hi, Jeff.
JEFFREY HOFFMAN: Well hi, Ira, it's always good to talk. We go back a long way.
FLATOW: A long way, back to the first shuttle launch.
PETTIT: Jeff, we're going to have to stop conversing on the radio like this and just meet face to face again sometime.
HOFFMAN: I'll be in Houston in January. I'll send you an email about it. We'll get together.
FLATOW: We're going to charge you for this phone call.
FLATOW: We have just a couple minutes before we take our break and go to our audience for all the questions. So let me start off, with a couple minutes to go. The question: What is the most challenging part for your life as an astronaut? What tests do most candidates wash out in in astronaut school? What's the biggest challenge? Let me ask you, Jeff, first.
HOFFMAN: Well, actually it's in the selection process. A remarkable number of people don't pass the physical, and particularly these days when we're selecting astronauts specifically for long-duration space flights, there's a lot of things which even if you're a perfectly normal, healthy person, just because of special situation involved in long-duration space flight, you would not qualify.
Once you're in, NASA will do everything possible, even if you develop medical problems, to keep you healthy and keep you flying. But getting in in the first place is tough.
PETTIT: And I agree with Jeff on that, and talking about the category of once you're in, some of the challenges of just doing the job is how you juggle excelling at work and still maintaining your family because this job can take every waking hour, and you have to figure out to juggle your work and maintain your family at the same time, which is not that different for many jobs all across America.
FLATOW: All right, we're going to take a break and take phone calls. Ask an astronaut, our number 1-800-989-8255. We're here with Flora Lichtman and astronauts Don Pettit, Jeffrey Hoffman. You can also tweet us @scifri, @-S-C-I-F-R-I. Here's your chance to ask an astronaut. It may not come again. So stay with us. We'll be right back after this break.
(SOUNDBITE OF MUSIC)
LICHTMAN: This is SCIENCE FRIDAY. It's our Ask an Astronaut hour. Our guests are NASA astronaut Don Pettit, who's flown three times in space, and his most recent trip wrapped up earlier this summer, after the six-and-a-half months aboard the International Space Station. And we have Jeffrey Hoffman, who was a NASA astronaut for almost 20 years, and now he's a professor at MIT. But he made five trips to space before hanging up that spacesuit.
And we have one, I think, that's good for you, Don. It comes from Twitter, from Walt on Twitter: What does it smell like in the ISS?
PETTIT: Oh, well, inside the space station, there's a lot of machinery and things like that, and it kind of reminds me of being in an engine room on a ship, or around a bunch of machinery and mechanical parts. And what it doesn't smell like is an Alpine forest or a woodland meadow or anything that reminds you of nature.
FLATOW: Jeff, you had even closer quarters in the Shuttle. Was the odor any different?
HOFFMAN: Well, I will say that one of the fortunate aspects from the olfactory point of view in space flight is that without gravity constantly pulling on your body, the fluids tend to shift to your upper body, including in your head, and the sense of smell is somewhat reduced. It's a little bit like when you have a sinus, stuffy nose, headache, which I think, given the smells that are present up there - remember, we don't have showers in space. We sort of take a sponge bath. We don't do laundry. So you tend to wear clothes for - until you can't wear them anymore. So it's probably just as well that the sense of smell is somewhat diminished.
PETTIT: Yeah, I agree with that, particularly after about six months.
HOFFMAN: I've watched the faces of some of the crew after you land, when the hatch to the Shuttle opens, and the first person comes in. It's interesting to watch how their noses wrinkle up when they get the first whiff of the air that we've become used to and aren't really that sensitized to. So I suspect it's as Don says: It's not an Alpine meadow up there.
FLATOW: Timothy Grant(ph) from Twitter asks: What's the emotional feeling when the clock his T-zero, and you start to feel that thrust?
HOFFMAN: You'll get different answers from different astronauts. There are some people who tell you that they really don't like launches because of the risk involved, and they love being in space, but they'd just as soon there were a safer way to get up there.
Everybody has their own way of dealing with risk. I guess I'm fortunate enough, I've always been able to take the attitude that it - I'm prepared for something. Everything that I can possibly do if we have a problem, I've been trained in. I'm confident that I and my crewmembers can do it. And if something happens that I don't have any control over, well, there's no point worrying about it.
So I remember my very first flight, when I realized, you know, I've been dreaming of doing this since I was six years old. Sit back and enjoy the flight. And it really is quite an experience. I mean, when the engines light and you get that big kick in the pants and you look out the window and ground is falling away from you and you break the speed of sound and about 45 seconds going straight up, I mean, it is a feeling of immense power. And, for me, it's always been incredibly exciting. At the same time, I'm sort of holding on and hoping, geez, I hope this thing holds together. And it always has.
LICHTMAN: Let's go to the phones. Jim in Birmingham, Alabama, welcome to SCIENCE FRIDAY. Do you have a question?
JIM: Hello, yes. I'm a baby boomer, born in 1954. Sputnik was launched in 1957, when I was three. Twelve years later, astronauts were walking on the moon. And there was just such a tremendous rate of progress. You know, many in my generation came to expect that, well, by the year 2012, people will be living in colonies on the moon and on Mars.
You know, it's - we built this wonderful International Space Station, but, you know, nature gave us a great space station right up there only a quarter of a million miles away. And I kind of feel a little ripped off that we didn't get that future. And I want to know if you guys kind of feel that way, too.
PETTIT: Well, I don't feel - I feel that we've been moving slowly, but we've been making steady progress. And the best is yet to be in terms of human beings expanding away from Earth. And one thing that I think history will show, when the space station - when we're looking back and space station years like we're currently looking back at the Apollo years, people will remark on, one, how difficult how that was, and how much we learned from that.
But right now, we're right in the middle of all of that, and we really don't see the forest for the trees - at least those that aren't intimately involved in the program. And I kind of think it might have been that way with the Apollo program, as well. After the first trip to the moon, people were wondering: Why are we keeping - keep going back? And afterwards, we say: Gosh, why did we quit going to the moon?
Anyway, I think we are making progress with human exploration in space and with robotic exploration of space, and hang on to your hats, because what we will uncover in the future, I think people will find amazing.
FLATOW: We're got a tweet here from ScottMo(ph), who says: Did traveling to space affect your faith, and if so, how? Any comments on that?
HOFFMAN: Well, I'll mention - a lot of people ask that. Being in space, it's not a sectarian experience, in that sense of affecting faith. I mean, we've had people from all the major religions, as well as agnostics and atheists. I think the one common thing that everybody will say is that being up there, looking back at the Earth, looking out at the universe from a completely different perspective, it gives you a sense of true awe, and I mean in the deepest sense of the word.
And in some cases, that is translated into a personal religious faith, in other cases not. That really depends more on the individual's, you know, personal religious feelings. But that sense of awe, I think, is something which we all share.
LICHTMAN: Here's a question from Facebook, from Rebecca Starr(ph). She asks: Would you rather help build a moon base or go to Mars on a manned mission? Don, either?
PETTIT: I will take whatever falls in my lap. However, I think it's wise to go to the moon and build a moon base before we venture off on Mars. And that's a personal opinion, and I know these opinions vary widely. I like a quote that I heard from Krafft Ehricke, who was a German rocket scientist that came to the United States and helped us with our program after World War II.
And I heard him give a talk, and he said that if God had intended man to be a space-faring species, he would have given us a moon.
FLATOW: That's quite interesting.
HOFFMAN: On the other hand, I have to say, I don't think, at the moment, that we really need to build a moon base, because I'd like to explore the moon. The moon is a big place, and there's a lot of places to explore before we actually commit ourselves to building a base at any one specific part. I think what we really should do is take off kind of where the late Apollo missions left off and apply 21st-century technology and figure out how to do it affordably.
This actually relates back to one of the previous questions of, you know, why didn't we keep doing it? I mean, it really was amazing that we developed this incredible capability to go to the moon, and then we threw it all away. But people have to remember that when President Kennedy challenged us to go to the moon, it was never planned to be a continual, sustained process.
We were there to beat the Russians, and we did, and then we stopped. We've got to learn now how to do it more affordably and do it sustainably so that we can keep on going, and that's, I think, what the big challenge is going to be.
LICHTMAN: Let's go to the phones - Daniel in El Cerrito, California.
DANIEL: Hi. I just want to say thank you, first off, for SCIENCE FRIDAY. I listen every Friday at work, and it's always good entertainment. And I just wanted to thank Don for his Science off the Sphere YouTube channel, because I watch that all the time, and I encourage anyone who hasn't seen it to check it out. And I'll take the comments off the air, thank you.
FLATOW: Well, we do the best we can in bringing you our stuff. And Don?
PETTIT: I thoroughly enjoyed making the raw material that the APS site and Science off the Sphere were able to warp into a presentable manner for viewing. And I think they have about 15 or 16 episodes now. I made enough material for about 40 to 45 episodes.
FLATOW: Wow. Wow.
PETTIT: So, again, the best is yet to be.
FLATOW: We're going to have you and Flora get together.
LICHTMAN: Yeah. Let's talk about that later.
FLATOW: Well, you know, one thing that you have in common, both of you - and we will - I was thinking about this before - is that you both investigated how toys work in space. You spent a lot of time doing that.
HOFFMAN: Yeah, I - it was on my very first space flight. We did the first toys in space. We really started it as an educational project. You know, how do you do something that young kids can relate to? Because you talk about weightlessness and gravity and Newton, and, you know, that's fine at high school and college. But elementary school students haven't really studied a lot yet, but they sure know how toys work. And to see how differently a lot of them behave in space really brings home to them that you're in a very different environment.
And I think this has been - this whole theme has been taken on other flights, and Don's done a great job with it. And, you know, anything that we can do to excite these young kids, get them interested, get them thinking about how things work, you know, that's what creates budding scientists and engineers, and we need more of them.
PETTIT: And there's a common scientific engineering thread in many of our toys, and I think that can be demonstrated by people like Jeff and I. We just haven't grown up. We're still playing with our toys.
LICHTMAN: I'd like to remind people...
HOFFMAN: We haven't grown up. You sound like my wife.
LICHTMAN: People should go to our website and check out some of Don's videos, which we have. Remember that the classic "Candy Corn in Space" video came from Don Pettit.
FLATOW: I just showed that at the AGU...
LICHTMAN: Oh, yeah?
FLATOW: ...previously, a little bit of that. Yeah, it's a great - great stuff there. And I remember Jeff used to come on. When we did Newton's apple, we had some of his stuff on.
HOFFMAN: Yeah. Yeah.
PETTIT: Oh. And...
HOFFMAN: We had yo-yos in space. That was a lot of fun.
PETTIT: And speaking of the candy corn, I reshot that again in high definition on this last mission where I started earlier in the sequence of shoving the candy corns into the sphere. So I - when I find that video chunk in some - some 10 terabytes of data that came back from my mission, I'll be able to put together a candy corn version two.
FLATOW: All right. We'll have to get - I'll have to have Leslie Taylor bring our - our webmaster bring up that "Candy Corn in Space" on our website because that feature is great also. And...
LICHTMAN: Yeah. I look forward to the sequel. I have a question for you that I've been wondering about, flip one of my own in. When you dream in space, do you start dreaming in zero G?
HOFFMAN: I tend not to remember a lot of dreams because you only remember your dreams if - when you wake up while dreaming. But I do remember one dream on my very first spaceflight, and I actually dreamed that I was back on Earth, which is bizarre.
I will say that when I was back on Earth during my 20 years as an astronaut, I never dreamed about space. But once I left the astronaut office and I realized I wasn't going to get into space again, I started to have dreams about being in space, which obviously shows that it did have some impact on my psyche.
FLATOW: This is NPR - this is SCIENCE FRIDAY from NPR. I'm Ira Flatow with Flora Lichtman, talking with two astronauts: Don Pettit, Jeff Hoffman. Don, did you dream in space?
PETTIT: Yes. When I'm on Earth, I dream frequently about flying, and I don't have to flap my arms. I just kind of lean back, and I'm floating around the room, not like Peter Pan, but - because if I say that, then some of my colleagues will put my face on a Peter Pan and tape it to my office door. But anyway, it's sort of like Peter Pan.
When I'm in space, I dream about walking, you know, walking in fields of grass and walking through the woods. And I think it just shows that human beings are malcontent, that wherever they are, they want to be someplace else.
FLATOW: Hmm. Let me get a tweet in from Thomas Burns(ph), who says: My nine-year-old son wants to know how long they train to be astronauts, and what should he do now to start training?
PETTIT: Ooh. Math, science and engineering.
FLATOW: STEM. Yeah.
HOFFMAN: And don't forget your English and foreign languages because we've got to communicate, and spaceflight these days is more and more an international enterprise. But I think the general thing in particular for younger students is excellence in everything you do, and that's what NASA will look for when they select astronauts.
PETTIT: And if you look at what the job entails, we're going someplace where human beings really weren't meant to be. And the only reason we can be there is because we take machines with us, mechanisms to give us the things that we need, whether it's propulsion and attitude control or life support.
And you have to understand how these machines work, or you're literally not even a babe lost in the woods. You're a babe lost in space. And you got to know how these machines work. You got to know how to fix them when they break because they always seem to be breaking, and that's just the way it is. And that takes math and science and engineering.
And so I tell students of all ages that if you want to fly in space, at least in this era of time, you got to know how to do these things, because if something breaks down or you don't know what to do, it's no longer minus 10 points on an exam.
FLATOW: You know, Jeff's comments about another - speaking another language is relevant even more so. I know he didn't mean it this way, but we may not be the country that goes back into space. You may want to learn another language for the country that may beat us going back there in - to the moon or to Mars. Flora, you got...
LICHTMAN: Yeah. We have a tweet that asks: Does food taste different in space? Just to lighten it up.
FLATOW: Does food taste different in space?
HOFFMAN: Well, I commented how your sense of smell is decreased. Because of that, a lot of astronauts tend to put hot sauce, extra, you know, Tabasco sauce - they give us a lot of Tabasco sauce and I used a lot more in space than I do back home.
FLATOW: Maybe it's because you were based in Houston.
FLATOW: I think that did it.
HOFFMAN: Well, we like our spicy food down there, the jalapeno peppers. People have taken jalapeno peppers out there. It's, yeah. So, you know, you don't go into space to have a three-star gourmet experience.
HOFFMAN: But the food, in reality, is a lot better than it used to be. If anybody who's done backpacking, the dehydrated foods, the meal's ready to eat that were originally developed for the military, is certainly a far cry from, you know, squeezing your dinner out of a tube like they did back in the Mercury and Gemini days a long time ago.
FLATOW: All right. We're going to take a break and come back and talk lots more about space. Our number, 1-800-989-8255. You can also tweet us @scifri, S-C-I-F-R-I. Don't go away. We'll be right back after this break.
LICHTMAN: This is SCIENCE FRIDAY from NPR.
(SOUNDBITE OF MUSIC)
FLATOW: This is SCIENCE FRIDAY. I'm Ira Flatow, with Flora Lichtman. It's our Ask an Astronaut hour.
LICHTMAN: Our guests are NASA astronaut Don Pettit, who's flown in space three times and just got back from a six-and-a-half month stint aboard the ISS, and Jeffrey Hoffman, who is a NASA astronaut for almost 20 years and is now a professor at MIT. And let's go straight to the phones. Eric in San Francisco. Welcome to SCIENCE FRIDAY.
ERIC: Hi, thanks a lot and thanks for being on the show. My question is whether or to you believe that intelligent life exist elsewhere in the universe, and if so, have humans been noticed by it?
PETTIT: I have not seen any evidence that intelligent life exists elsewhere, no green men with almond-shaped eyes in flying saucers and things like that. So if there - in the terms of is there life out there, there could very well be life on Mars. We've seen some evidence that there might be life on Mars from fossils found in Martian meteorites that have ended up on Earth. And it will be interesting to see as time unfolds with our Martian exploration whether we ultimately run across some form of simple life forms on Mars and whether or not we call them intelligent, I guess we'll just have to see what happens when we run across them.
FLATOW: I have one other question while we're talking about, Don, you spent six months in space. NASA just announced that they're going to be putting a program together to put an astronaut in the space station for a year. What's the biggest piece of advice you can give to that person who's going to be - or people who are going to be spending a year in the space station?
PETTIT: Pack your bags wisely.
PETTIT: There's a lot to it in terms - if you're going to be off the planet for that length of time, you need to make sure that you have a number of personal and family things taken into account before you go. And where you're going, you want to carefully think about what you might bring with you. You're allowed to bring a small volume of personal things and you need to make sure that you're going to have hobbies, basically, that you can work on in your off-duty time. There is some off-duty time and you can't work all the time. And during your off-duty time, you need some meaningful way to spend these off-duty moments,
LICHTMAN: Let's go to Ken in Clarksville, Tennessee. Hi, Ken.
LICHTMAN: You're on SCIFRI.
KEN: Yes. OK. I just want to ask if - what they think of - somebody mentioned terra-forming Mars and the moon earlier and I was going to ask what would they think of putting sulfur hexafluoride plus two earth gases like nitrogen and oxygen, you wouldn't need a lot because all we need to do, if the plant's growing, it would make the oxygen. Some nitrogen would be needed. But the sulfur hexafluoride is to get the - to cause a greenhouse gas warming of Mars, because at 80 degrees, you know, average temperature of 80 degrees below zero, I don't think plants are going to do well. But...
LICHTMAN: Bring climate change to Mars.
HOFFMAN: I can talk about that a little bit. We actually believe from what we've learned about Mars, that at one time Mars probably did have an atmosphere and there was liquid water on the surface. The problem is that Mars, we think, once had a magnetic field which blocked cosmic rays and the solar wind from coming in. Mars cooled off, the magnetic field stopped and the solar wind basically ripped away Mars' atmosphere which - and that's the problem. If you- to try to terra-form Mars without creating another Martian magnetic field, you would just loose the atmosphere all over again, unless, we could figure out some other way of maintaining the atmosphere. I don't want to say it's impossible to do, but it would take a tremendous amount of energy and technology which, at the moment, we absolutely do not have.
FLATOW: Well, gentlemen, I want to thank you both for taking time to be with us today. Don Pettit, NASA astronaut who has logged more than 350 days in orbit. He just got back from spending a six-and-a-half months living aboard the International Space Station. Jeff Hoffman, who was a NASA astronaut for almost 20 years. He has flown in space five times including this Herculean effort that he and his colleague did to repair - the famous repair of the Hubble Space Telescope. We have you and your fellow astronauts to thank for that. He is now professor in the department of aeronautics and astronautics at MIT. Thank you, guys, for taking time to be with us.
PETTIT: Always a pleasure. Bye-bye, Ira.
HOFFMAN: It's a pleasure.
FLATOW: Happy holidays to you.
LICHTMAN: Thanks (unintelligible). Transcript provided by NPR, Copyright NPR.