What do you want to know about living and working in space?

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Your Comments, Thoughts, Questions, Ideas

wowy's picture
wowy says:

i think that will be cool and a kindof scary too

posted on Thu, 05/17/2012 - 11:21am
James Flaten's picture
James Flaten says:

Outer space is a very hostile environment to people (which is why a lot of spacecraft are purely robotic), but astronauts all say it is definitely cool to go into orbit. I also think it is cool to be involved in designing, building, and operating things that go into outer space (or near-space) even if you don't get to go up there yourself.

posted on Mon, 05/21/2012 - 3:02pm
missy's picture
missy says:

how old do you have to be to go to space

posted on Thu, 05/17/2012 - 8:54pm
James Flaten's picture
James Flaten says:

There is no specific age limit, but most people selected to go into orbit in outer space are well-accomplished in their fields, which means they are beyond college age. Many astronauts are in their 30's and 40's. The youngest person to orbit the Earth so far was a Russian (G. Titov) at age 25. The oldest person was John Glenn, who returned to space at age 77. As suborbital flights for paying passengers become more common in the future it is likely that younger (and perhaps older) people will get to go into space, albeit for only a few minutes.

posted on Mon, 05/21/2012 - 2:01pm
aht's picture
aht says:

How much can a space ship carry?

posted on Thu, 05/17/2012 - 9:01pm
James Flaten's picture
James Flaten says:

Spaceships vary in size and capacity -- a lot! The first thing the U.S. put into orbit was Explorer 1 which had a mass of less than 10 kg (i.e. a weight of less than 20 lb). That was unmanned, of course. The Mercury capsules had a mass just over 1000 kg and were large enough to carry one person. The Space Shuttle, on the other hand, carried a crew of 6 of 7 and could deliver over 24,000 kg into low-Earth orbit. The Saturn V rocket that sent people to the Moon stood just over 100 m tall and was able to either lift about 120,000 kg into low-Earth orbit or 45,000 kg, including a crew of 3, into trans-lunar injection.

posted on Mon, 05/21/2012 - 2:58pm
Duane Olson 's picture
Duane Olson says:

1. What, exactly, is a black hole?

2. What is your assessment of the string theories?

posted on Fri, 05/18/2012 - 10:33am
James Flaten's picture
James Flaten says:

A black hole is an object so compact yet so massive that even light cannot escape its gravitational pull -- hence it appears black. Although they cannot be seen directly, black holes can be detected indirectly by noticing their influence on nearby objects -- stars can orbit black holes and occasionally even fall into them; light passing near a black hole will be distorted. Compact gravitational objects are formed by the death of certain massive stars -- when their nuclear fires go out stars collapse into a variety of objects including white dwarfs, neutron stars, or black holes, depending on their mass and the details of their collapse, as well as their ability to accumulate additional mass from nearby objects after their initial formation.

I don't claim to know much about string theory -- sorry, Duane! :)

posted on Mon, 05/21/2012 - 3:10pm
Hayley's picture
Hayley says:

Hi. I was wondering, what do astronauts eat while they are in space?

posted on Fri, 05/18/2012 - 12:06pm
James Flaten's picture
James Flaten says:

When it comes to eating, astronauts have a lot of food choices these days -- not just food-in-tubes of the early days -- but it is best not to eat foods that crumble easily lest the crumbs float away and cause problems elsewhere in the spacecraft. Foods usually need to be able to be maintained at room temperature during space flights, though they can be reconstituted with water and/or heated prior to being eaten. Freeze-dried foods are quite common.

Here is a sample daily menu from a Russian crew on the International Space Station (ISS), which features more than 300 different types of foods to choose from, taken from Wikipedia:
Breakfast: curds and nuts, mashed potatoes with nuts, apple-quince chip sticks, sugarless coffee and vitamins.
Lunch: jellied pike perch, borsch with meat, goulash with buckwheat, bread, black currant juice, sugarless tea.
Supper: rice and meat, broccoli and cheese, nuts, tea with sugar.
Second supper: dried beef, cashew nuts, peaches, grape juice.

posted on Mon, 05/21/2012 - 3:20pm
1d's picture
1d says:

they eat dehidraytied food and the way they make is that they put it thogh a machine witch dehidrats it so its smaller so that they have alot of room 2 store it

posted on Tue, 08/28/2012 - 12:47pm
Anonymous jones's picture
Anonymous jones says:

how did you make that look so cool

posted on Fri, 05/18/2012 - 1:30pm
James Flaten's picture
James Flaten says:

I'm not quite sure what you were referring to, but riding a hovercraft, for example, is a lot of fun. Try it if you ever have the chance! Astronauts need to learn to control their motion in an environment where there isn't gravitationally-induced friction, and one can learn how to do that using hovercraft that you can ride.

posted on Mon, 05/21/2012 - 3:32pm
Lila Faye Lohmiller's picture
Lila Faye Lohmiller says:

If you had to throw your lunch up, would it go up, due to loss of gravity?

posted on Fri, 05/18/2012 - 2:08pm
James Flaten's picture
James Flaten says:

There is in fact plenty of gravity in outer space -- spacecraft and people inside them are continuously falling as they orbit the Earth. It just looks like there is no gravity since everything falls together, so things appear to float with respect to one another.

Space-sickness is quite common for space travelers, especially when they first go into orbit and need to get used to the "stomach-in-your-throat" feeling, like on a roller coaster or fast elevator, but 24 hours a day. Fortunately (or unfortunately, depending on your perspective), you don't need gravity to throw up. Whatever you throw up will travel in the direction you are facing, whether that is "up" or not, so it is best to capture it in a "space-sickness" baggie.

Luckily, most people get used to the sensation after a while, possibly with the help of medications, after which spaceflight is downright fun (even the eating part).

posted on Mon, 05/21/2012 - 3:28pm
1d's picture
1d says:

no beacuse there is gravity in thespace ship

posted on Tue, 08/28/2012 - 12:49pm
Vanessa's picture
Vanessa says:

How do you sleep in space?

posted on Fri, 05/18/2012 - 6:40pm
James Flaten's picture
James Flaten says:

Astronauts tend to use sleeping bags which they just hitch to the "wall" of their sleeping quarters. There isn't really an up or down in a spacecraft, so astronauts might not all sleep facing the same way. Some astronauts find it hard to sleep since they are used to having their head pressing against a pillow, so they may strap a pillow to their head with an elastic band to mimic that sensation.

posted on Mon, 05/21/2012 - 3:35pm
Anonymous 101's picture
Anonymous 101 says:

Wow! That is really interesting. Sometimes do you judt not sleep at all because you can't get comfortable? Thanks for sharing!

posted on Fri, 06/29/2012 - 3:31pm
maya's picture
maya says:

What is it like being in space?
When will America go back in to space?

posted on Sat, 05/19/2012 - 11:54am
James Flaten's picture
James Flaten says:

I've never been in outer space myself, but I've talked to people who have and they all say it is awesome -- especially the view! I like to watch movies showing what it looks like from outer space and I like to do activities on the ground, like riding hovercraft to experience friction-free motion, to help me experience some aspects of the outer space experience. If you ever have a chance to meet an astronaut they can tell you lots of interesting stories about what it was like for them to be in outer space.

As for going back in to space -- America never left! Right now there are two American astronauts on the International Space Station (ISS) and we have more astronauts training to go there. Since the recent retirement of the Space Shuttle the only change is that American astronauts are flying to and from the ISS on Russian rockets, as opposed to us taking turns with the Russians carrying crews and cargo to the ISS.

The future of NASA launch vehicles to carry people is a bit unclear right now, with the halting of the Constellation program but continued development and testing of the new Space Launch System (SLS) vehicles. Commercial companies are also making progress on being able to carry payloads and crews into low-Earth orbit. For example, a SpaceX Falcon 9 rocket and Dragon capsule are set of launch to the ISS any day now. I expect we will be back in the business of launch people into space within a few years (it takes a long time to develop and test new rocket systems) and we continue to launch unmanned vehicles into space all the time.

posted on Mon, 05/21/2012 - 3:51pm
natalia's picture
natalia says:

i love science! that means i love this!

posted on Sat, 05/19/2012 - 3:14pm
James Flaten's picture
James Flaten says:

I'm glad to hear it! As you grow older, get involved with all the science and math that you can, both in and outside of school. That will give you the most options once you get through college and enter a long-term career. Perhaps it will have something to do with space!

posted on Mon, 05/21/2012 - 3:55pm
Emanuel's picture
Emanuel says:

What is the surface of the moon like?

posted on Sun, 05/20/2012 - 1:23pm
James Flaten's picture
James Flaten says:

The surface of the Moon is a bit like a desert -- dry and dusty and nearly all one color. The Moon has lots of rocks of different sizes, as well as craters. Since there is no atmosphere nor water to erode them away, patterns in the dust (like astronaut footprints), last essentially forever. Buzz Aldrin, on the first crew to land on the Moon, described the surroundings as "magnificent desolation."

posted on Mon, 05/21/2012 - 4:00pm
atifa's picture
atifa says:

I was wondering if there was a such thing as a zero gravity pen.

posted on Sun, 05/20/2012 - 2:53pm
James Flaten's picture
James Flaten says:

A "Zero-Gravity Pen" (AKA "Space Pen") was developed with a pressurized ink cartridge so that it can write at any angle (i.e. it doesn't need gravity to help ink flow out of it). Space agencies have had to deal with how to write in orbit and standard pens and pencils, both regular and mechanical, all have issues. The Space Pen was not developed for use in space, exclusively, but has in fact been used by astronauts.

Remember that "free-fall" is a better description of what you experience when in orbit, rather than "zero-gravity." These pens work in free-fall too...

posted on Mon, 05/21/2012 - 4:10pm
Dalton's picture
Dalton says:

Hello Mr Flaten
Do you think it would be better to send humans or robots into space?

posted on Mon, 05/21/2012 - 9:52am
James Flaten's picture
James Flaten says:

People argue over this question a lot. In broad terms, astronauts are the hardest payload to send into outer space because they need to be cared for much more extensively than robots and they always want to come back to Earth at the end of their mission! Thus robotic spacecraft are the only way to go for one-way missions to distant planets. On the other hand, it took the two rovers on Mars months to accomplish what a single geologist astronaut could have accomplished in just a few hours, so people can sometimes get things done faster and are better able to adapt to changing conditions.

As we look toward the future there needs to be room for both manned and unmanned spaceflight. Most hard science is likely to be done by robotic spacecraft, but frankly, it is more engaging to the general public to hear what astronauts are doing. Funding for spaceflight tends to be related to interest on the part of the general public (and the government), so human spaceflight is probably here to stay, and expansion beyond where we've sent people in the past (low-Earth orbit and the Moon) is likely, though not for a few years. Presently NASA is stepping away from sending people into low-Earth orbit, allowing private companies to do that, but NASA is looking into much bigger goals like sending people to the Moon or to an asteroid or to Mars.

posted on Mon, 05/21/2012 - 4:21pm
Burgermeister Meisterburger's picture
Burgermeister Meisterburger says:

Is the gravity on space like being in a pool?

posted on Mon, 05/21/2012 - 1:48pm
James Flaten's picture
James Flaten says:

When you are in orbit you are continuously falling which means that the floor isn't required to support you. (If you were really in a zero-gravity environment the sensation would be similar.) Astronauts train underwater to simulate free-fall because you can inflate or weigh down their spacesuit so that they achieve neutral buoyancy and neither float nor sink. In fact, being surrounded by water produces more friction than being in outer space, but if you are in a stiff spacesuit you might not notice that very much. To read about NASA's Neutral Buoyancy Lab (NBL) at the Johnson Space Center in Texas, go to

Another way to train for free-fall is to fly in a plane following a parabolic trajectory, giving you about 20 seconds of genuine free fall at a time (interspersed with periods of higher-than-standard acceleration). This works well, but there are many tasks for which astronauts train that cannot be fully accomplished in 20-second intervals, so training in a neutral buoyancy pool remains useful.

posted on Mon, 05/21/2012 - 4:30pm
Katie Framstad's picture
Katie Framstad says:

My ears pop a lot when I go in a plane.. how pressurized are spacecrafts astronauts use when they are in outerspace? Would my ears hurt if I were to go out there?

posted on Thu, 05/24/2012 - 1:33pm
James Flaten's picture
James Flaten says:

We are used to living at the bottom of the Earth's atmosphere (we call that 1 atmosphere of pressure) but the human body can in fact deal with somewhat higher and somewhat lower pressures if need be, as long as there is enough oxygen in the air to sustain life.

Pressured aircraft often don't bother maintaining a full 1 atm of pressure, which is why your ears pop as they ascend and descend. Both the Space Shuttle and International Space Station (ISS) maintain standard air pressure and oxygen content, for the comfort of their occupants. On the other hand, spacesuits are often pressurized only to about half an atmosphere (and they have a different oxygen fraction) so astronauts have to be careful to purge their bloodstream of excess nitrogen before donning a spacesuit to avoid the "bends". This is sort of opposite to what deep sea divers face when they go into high-pressure environments underwater.

As for your ears, they'd be fine inside something like the ISS but if you did an EVA in a spacesuit they might hurt, at least until you got used to the lower pressure.

posted on Thu, 05/31/2012 - 11:10am
leroy jenkin's picture
leroy jenkin says:

what animals have gone in to space

posted on Fri, 05/25/2012 - 11:50am
James Flaten's picture
James Flaten says:

Both the United States and the Soviet Union sent animals into space before they sent humans into space, to test the ability of living things to survive in outer space. Probably the most famous (though not the first) animals in outer space were the Russian dog Laika on Sputnik 2 in 1957 and the American chimpanzees Ham and Enos, in 1961.

Other animals that went into space before the ones mentioned above included fruit flies and rhesus monkeys (in the 1940's) then mice, rabbits, more monkeys, and other dogs (in the 1950's).

After spaceflight for people became more common, animals continued to be flown to see how they adapt to free-fall. Animals included frogs, cats, beetles, wasps, spiders, turtles, rats, bird eggs, moths, worms, butterflies, fish, ants, and more! Amazingly enough a few animals, such as water bears, can even survive in the total vacuum of outer space for days a time (but most animals taken to outer space are kept in pressurized compartments).

posted on Thu, 05/31/2012 - 12:22pm
QuackPackAttack's picture
QuackPackAttack says:

Is it likely, in your opinion, that we will discover a so called 'sister' planet of earth; capable of suporting life, liqiud water etc.?

posted on Fri, 05/25/2012 - 5:19pm
James Flaten's picture
James Flaten says:

The search of "habitable" planets is of great interest to NASA. Leading the way in this effort is the Kepler space telescope, launched in 2009, which continuously monitors the brightness of over 100,000 stars in a fixed field of view, looking for regular dimming events that might indicate the transit of a planet across the face of a distant star. Once an extra-solar planet has been found, calculations are done to see if it could possibly support water in liquid form.

Results so far include over 2000 extra-solar planet candidates, several dozen of which lie in the "habitable zone" around their parent star, though these planets are not necessarily Earth-sized. Earth-sized planets are so small compared to stars that even Kepler has a very hard time detecting them, but in December of 2011 the Kepler team announced the identification of two such planets, both orbiting the same Sun-like star now named Kepler-20.

posted on Thu, 05/31/2012 - 12:37pm
Greg Van Sickle's picture
Greg Van Sickle says:

Why couldn't the apollo csm and LM have been placed in the cargo bay of the space shuttle so the moon missions could have continued??? Once in earth orbit the stages of the Saturn V were exhausted and it was the engine of the CSM that pushed the space ship to the moon (and back)...

posted on Sat, 05/26/2012 - 9:07pm
James Flaten's picture
James Flaten says:

Interesting point! In fact, the Apollo Command Module, Service Module, and Lunar Module all together weigh too much for a single Space Shuttle to lift into low Earth orbit (though technically they might just fit into a Space Shuttle cargo bay). If the Apollo hardware could have been divided between two shuttle flights and reassembled in space, this idea might have worked. However the shuttle wasn't fully operational until about 10 years after the last of the Apollo moon shots, far too long to resuscitate the unflown (and mostly unfinished) Apollo CM, SM, and LM's left behind when the Apollo program was cancelled.

Later addition to answer: The third stage of the Saturn V fired twice, first with a 2.5-minute burn to achieve a parking orbit around the earth, then later with another 6-minute burn for trans-lunar injection. The service module engine was only used for course corrections and for burns to get into and out of lunar orbit. To accomplish a lunar mission with Apollo equipment carried into low earth orbit on Space Shuttle payloads, you would also need to provide an extra (very big!) engine for trans-lunar injection.

posted on Thu, 06/14/2012 - 1:36pm
Aaron CF's picture
Aaron CF says:

how does the Hubble work?

posted on Sun, 05/27/2012 - 2:06pm
mekhi's picture
mekhi says:

How do space ship engines work? How are they built?

posted on Mon, 05/28/2012 - 12:24pm
James Flaten's picture
James Flaten says:

Like rockets that launch things from the surface of the Earth into outer space, spaceships also must use rocket engines to propel themselves in the vacuum of outer space. Unlike aircraft engines which interact with the air around them, rocket engines for use in outer space must be completely self-contained, carrying everything they need to sustain combustion in a chamber and eject high-speed gases through a nozzle. As the rocket pushes the gases backward, the gases react by pushing the rocket forward (according to Newton's Third Law of Motion), so rocket engines are sometimes called reaction engines.

Solid-fuel rocket motors have propellants which contains pre-mixed oxidizers and fuel. They are simple and reliable but their main drawback is that they cannot be throttled down or stopped once ignited. Liquid-fuel rocket motors contain separate fuel and oxidizer tanks. The fuel and oxidizer are mixed just before entering the combustion chamber. Such motors can be throttled, quenched (sometimes), and restarted, but they are more complex than solid-fuel motors. Challenges for all rocket motors include dealing with very high temperatures and high combustion chamber pressures.

To learn about how rocket engines are built, try internet resources. For example, here are a couple of references to learn about the Space Shuttle's solid rocket boosters (SRBs) and its main engine (a liquid-oxygen / liquid hydrogen engine).

posted on Fri, 06/01/2012 - 5:37pm
isaiah 's picture
isaiah says:

How fast can a spaceship fly

posted on Mon, 06/04/2012 - 12:39pm
James Flaten's picture
James Flaten says:

Spacecraft pick up speed as their motors burn (or as gravity pulls them toward something), but coast without changing speed very quickly most of the time. A typical speed for a satellite in low-Earth orbit is about 7.8 km/sec (28,000 km/hr;17,500 mi/hr). Spacecraft leaving the vicinity of the Earth need to achieve Earth-escape velocity of 11.2 km/sec (relative to the surface). New Horizons, a spacecraft heading for Pluto, currently holds the record for fastest launch speed at motor burn-out -- 16.26 km/s (over 58,000 km/hr; over 36,000 mi/hr).

posted on Thu, 06/14/2012 - 1:46pm
JGordon's picture
JGordon says:

Hi, Professor Flaten! I have a few space-related question cards left at the museum by visitors, and maybe you can help out with the answers ...

Question card:
In the future, will people be able to live on the moon? Will it be only scientists that live there?

posted on Wed, 06/06/2012 - 11:42am
James Flaten's picture
James Flaten says:

Research is underway on technologies to allow people to build long-duration outposts on the Moon so I believe that in the not-too-distant future people, and not just scientists, will be living on the Moon.

Major problems to overcome include how to survive the lunar night (with lasts about 14 days, during which time the surface gets very cold) and how to make use of resources available on the Moon so we don't have to keep supplying those outpost exclusively from the Earth.

Current interest focuses on some regions near the Moon's south pole that are in continuous sunlight, so they don't get so cold, and nearby regions (in craters) that are in continuous darkness, which may harbor water-ice that could be used for human consumption, for growing plants, to make oxygen to breathe, to make rocket fuel, and more.

Water-ice has also been discovered on Mars, making future human habitation there much more feasible.

posted on Thu, 06/14/2012 - 1:57pm
JGordon's picture
JGordon says:

Another visitor question card:

How much does gravity vary from place to place on Earth? Do the variations affect space operations or orbiting equipment?

posted on Wed, 06/06/2012 - 11:43am
James Flaten's picture
James Flaten says:

The gravitational force from the Earth varies slightly due to altitude (from mountaintops to underground), due to the local composition of the crust, and also due to the fact that the Earth bulges slightly at the equator due to its spin (i.e. a dependence on latitude). Even when these effects are combined the changes in overall gravitational force are less than 1%.

It is possible to detect these small gravitational variations even from orbit and it can have a tiny (but cumulative) effect on the trajectory of spacecraft. This is one way that orbiting spacecraft around other solar system bodies can probe their subsurface structure. A good example would be the two GRAIL (Gravity Recovery And (lunar) Interior Laboratory) spacecraft mapping the gravitational field of the Moon.

posted on Thu, 06/14/2012 - 2:10pm
JGordon's picture
JGordon says:

Visitor question card:

How did you become a scientist? Why did you choose this career?

posted on Wed, 06/06/2012 - 11:44am
James Flaten's picture
James Flaten says:

I've been interested in doing experiments to try to figure out how things work as long as I can remember, which may have been a clue that I'd like science when I studied it in school. Certain fields always appealed to me more than others -- I liked physics and astronomy more than chemistry and geology, for example. My very first college lecture, 8 a.m. on Day 1, was a physics class and I was so taken that I never looked back!

My interests are broader, of course, including engineering, math, computer science, teaching, and music, but science (especially classical physics) remains near and dear to me and I'm glad to have a job (promoting interest in NASA and in aerospace) where physics knowledge is very helpful.

As I tell my students, "Figure out what you love and what loves you back." By that I mean figure out what you enjoy doing but select a field that you do well enough that other people appreciate your talent. I like doing art, for example, but I'm not good enough at it to make a living doing it. I guess that is what hobbies are for...

posted on Thu, 06/14/2012 - 2:57pm
JGordon's picture
JGordon says:

Visitor question card:

How many stars are in the galaxy? Do you think we will ever travel to any of them?

posted on Wed, 06/06/2012 - 11:45am
James Flaten's picture
James Flaten says:

We currently estimate that there are over 100 billion stars in our galaxy, the Milky Way, and that there are over 100 billion galaxies in the universe!

However, stars are widely spread apart, at least by human standards. The Sun is about 150 million km (93 million mi) away from us -- a distance that light can travel in about 8 minutes. The nearest set of stars (most stars come in groups of two or more) is the Alpha Centauri group which is over 4 light years away -- over 40 trillion km (24 trillion mi).

With such vast distances, I think it is unlikely that humans will "reach the stars" with any uninhabited spacecraft, much less inhabited spacecraft, in the foreseeable future. The two Voyager spacecraft, launched toward the outer solar system in the 1970's, are currently nearing the edge of the solar system -- but that is less than 1 light day away!

However with telescopes we can look far out into the universe and see what is there, even if we cannot get things there in a reasonable amount of time.

posted on Thu, 06/14/2012 - 3:15pm
JGordon's picture
JGordon says:

Visitor question card

How hot is the sun? Have we ever sent spacecraft there?

posted on Wed, 06/06/2012 - 11:46am
James Flaten's picture
James Flaten says:

The Sun, like the Earth, has layers which are at different temperatures. The surface of the Sun that we see in photos, called the photosphere, has a temperature of about 5800 Kelvin (5500 degrees C) (9900 degrees F). The core of the Sun is believed to have a temperature in excess of 15 million Kelvin but, interestingly enough, the tenuous corona (solar atmosphere outside of the photosphere) is also very hot -- from 1 to 2 million Kelvin.

Many spacecraft have studied the Sun from a distance as their primary mission, including Solar and Heliospheric Observatory (SOHO), Ulysses, and Solar Terrestrial Relations Observatory (STEREO).

I'm not aware of any spacecraft have actually been sent to crash into the Sun while studying it, nor any that plan to do so. MESSENGER, which is now in orbit around Mercury, is pretty close to the Sun -- much closer than any of the spacecraft listed above. However MESSENGER is studying Mercury, not the Sun.

posted on Thu, 06/14/2012 - 3:28pm
cool dude's picture
cool dude says:

When do you think a human will get to mars? How will a mars trip look different than a trip to the moon?

posted on Sun, 06/17/2012 - 2:02pm
James Flaten's picture
James Flaten says:

People have been talking about going to Mars since before we could even put people into orbit. Of the other planets, Mars is the most obvious target for human exploration. (Venus and Mercury are too hot and the gas giant planets of Jupiter, Saturn, etc. don’t have a solid surface on which to land.) But actually sending people to Mars remains decades away because it is such a big technical challenge and will require a lot of funding too. Maybe 2030 to 2040 might be a realistic guess. You will hear earlier dates upon occasion, but no one is really working hard enough on it right now to put a very accurate date on when it might be accomplished.

Getting to Mars is quite different than going to the Moon for a variety of reasons. The Moon is always nearby, at least in astronomical distance terms, but to go to Mars you need to wait for the right alignment of the planets in their orbits so launch opportunities are less frequent (perhaps about once every 2 years or so). More importantly, once you get there you need to wait again before returning, so you need to plan to stay at least for several months (as opposed to the Moon, where the first landing only lasted a few hours and later ones only lasted a few days). Most Mars missions expect a round trip time in excess of 1 year and even if supplies are available there are significant challenges with humans remaining healthy in “zero-gravity” conditions for that long. (Aspects of long-duration spaceflight are being studied onboard the ISS.) It would take a massive rocket to carry adequate supplies for a Mars mission so probably supplies, and possibly even habitats for astronauts, would be sent in advance and deposited/assembled robotically.

posted on Thu, 07/12/2012 - 12:42pm
Toby and Bennett's picture
Toby and Bennett says:

How do you leave the spacecraft to play outside? It sounds like fun.

posted on Mon, 06/18/2012 - 10:15am
James Flaten's picture
James Flaten says:

To exit a spacecraft you need to wear a spacesuit to provide you with your own personal atmosphere and to protect you from radiation and other hazards of outer space. You need to depressurize part or all of your spacecraft before stepping out into the vacuum of outer space. A room in a spacecraft for that purpose is called an air-lock.

Doing an EVA (extra-vehicular activity) does afford you a great view but usually astronauts only go outside if they are some tasks to do which cannot be done robotically. That said, it probably isn’t quite accurate to say you “leave the spacecraft to play outside,” though admittedly it would be fun!

posted on Thu, 07/12/2012 - 12:43pm
Mylanie's picture
Mylanie says:

is it possible that there are other living things out in space besides humans? If there is what could it grow into?

posted on Wed, 06/20/2012 - 4:05pm
James Flaten's picture
James Flaten says:

People have thought about extra-terrestrial (i.e. non-Earth-based) life for a long time but, despite reports of UFO’s and novels and movies, there isn’t much solid scientific evidence for any yet. But people keep looking and listening (with radio telescopes) for signs of life, and that is definitely a consideration when exploration missions are planned to targets around the solar system. There are lots of life forms on Earth but essentially all of them seem to depend on the present of water in liquid form. Hence as we search for life we pay special attention to planets and moons that can support water in liquid form – ones in the so-called “habitable zone” around a star.

Considering the vastness of the universe I think chances are very good that life exists elsewhere but that chances aren’t very good that we’ll ever encounter it. And even if we do, it probably won’t be much like us (either much more advanced or much less advanced), so meaningful communication with other life forms is actually quite unlikely.

posted on Thu, 07/12/2012 - 12:43pm
science's picture
science says:

what do you design that goes into space? how does it go into space? how does understanding about spce help us?

posted on Wed, 06/20/2012 - 4:33pm
James Flaten's picture
James Flaten says:

Part of my job here at the U of MN working for the MN Space Grant is to promote interest in outer space and one of the best ways to do that is have people design and build stuff then actually fly it into outer space. We build payloads that we send to NASA’s Wallops Flight Facility, to fly into outer space for a few minutes in their suborbital rockets. We also build miniature spacecraft which we can lift using helium-filled weather balloons into the stratosphere (AKA near-space), which is a lot like outer space. Over the past 5 years or so we’ve build about 4 suborbital payloads and also launched literally hundreds of payloads on more than 50 weather balloon flights. Photos taken and data from science sensors collected on these flights helps us understand the atmosphere, outer space, and the Earth itself better, and give participants hands-on skills so they can contribute to real outer-space flight projects in the future if they want to. Many technologies that we use all the time, such as cell phones, were developed in part due to the space program, so we all benefit, directly or indirectly, from NASA education activities.

posted on Thu, 07/12/2012 - 12:44pm
adam rocks's picture
adam rocks says:

Do you have to be a pilot to be an astronaut?

posted on Thu, 06/21/2012 - 1:16pm
James Flaten's picture
James Flaten says:

No. When the space program was first established the astronauts were mostly just along for the ride on nearly entirely automated spacecraft. Administrators debated what sort of people should be sent up – athletes, educators, circus/stunt people, scuba divers, test pilots, etc. Ultimately they settled on test pilots, many with military backgrounds, as the first astronauts. But since the early days of human spaceflight the background of people in the astronaut corps has become much more diverse. At the present time some astronauts are still pilots, but more are actually scuba divers, in part because of their comfort level working in (suba) suits in no-air environments. One person on a 6 or 7-person shuttle crew is called the “pilot” but even that person doesn’t do much actual flying. The bulk of the crew will be “mission specialists” or “payload specialists” and those astronauts, who do the EVA’s for example, aren’t necessarily going to be pilots.

posted on Thu, 07/12/2012 - 12:44pm
Curious's picture
Curious says:

How much education is needed to be an astronaut?

posted on Fri, 06/22/2012 - 1:44pm
James Flaten's picture
James Flaten says:

NASA provides all the training needed to be an astronaut, though you have to pass a lot of physical and psychological tests to get accepted into the training program. Currently astronaut candidates are required to at least have an undergraduate college degree, though not in any one specific field, and many have advanced degrees. Getting accepted for astronaut training is highly competitive, so it is fair to say that astronauts need to have done well in college too. At least of few years of post-college experience in an appropriate field (advanced studies can count) are also required.

To read more, check out

posted on Thu, 07/12/2012 - 12:45pm
babbycakes's picture
babbycakes says:

how do people eat in space??

posted on Mon, 06/25/2012 - 1:24pm
James Flaten's picture
James Flaten says:

Eating and drinking in space isn’t hard – peristalsis in the esophagus can push food down to your stomach even without gravity (which is why it is possible to eat even if you are upside down, though drinking is harder). However it wasn’t initially clear how being in free-fall in outer space might affect bodily functions (eating, sleeping, hearing, seeing, etc.), so early astronauts really were guinea pigs in that regard. The first American to orbit the Earth, John Glenn, had a tiny eye chart taped to his console that he had to read back to ground control during his flight to make sure his vision wasn’t failing.

Luckily, the human body works very well in nearly all regards in outer space, including eating. The main exception is muscle atrophy, since we don’t need our muscles to hold us up which in free-fall. Astronauts need to work out to maintain muscle mass and after long durations in outer space they are often quite weak (and may feel dizzy) for a few days after they return to the surface of the Earth.

posted on Thu, 07/12/2012 - 12:45pm
lemonade:)'s picture
lemonade:) says:

when will humans get to mars? and how? how long do you think it will be?

posted on Tue, 06/26/2012 - 12:41pm
James Flaten's picture
James Flaten says:

See my comments to the earlier question about missions to Mars. If you want to read more details about historical proposals for human Mars missions, check out http://en.wikipedia.org/wiki/Manned_mission_to_Mars.

posted on Thu, 07/12/2012 - 12:45pm
Chris W.'s picture
Chris W. says:

So with black holes, are they actually consider matter, or would they be considered antimatter? Also, based on their gravity, would any solid object near it literally be crushed due the immense amount of the gravity emitted by one?

posted on Thu, 06/28/2012 - 1:38pm
James Flaten's picture
James Flaten says:

Both matter and antimatter have mass, and hence gravity, so one could technically have an anti-matter black hole. However interactions between black holes and the matter (not anti-matter) around them leads astronomers to conclude that black holes that we know about are made of regular matter, not anti-matter.

Objects near a black hole are pulled towards it gravitationally. The strength of the gravitational force depends on your distance to the source and in the case of a black hole the gravitational force can change quite quickly even from the near edge of an object to the far edge. That said, as an object falls into a black hole it tends to get stretched and torn apart rather than getting “crushed” due to the high gravitational forces. This is somewhat counter-intuitive.

posted on Thu, 07/12/2012 - 12:46pm
Chris W.'s picture
Chris W. says:

What would a black hole be called if the gravity wasn't so strong? I mean, well, what would it look like if its gravitational pull didn't absorb light? What pigments do black holes even include? Thank you for spending the time to answer my questions.

posted on Thu, 06/28/2012 - 2:50pm
James Flaten's picture
James Flaten says:

A black hole is so-named because its strong gravity deflects light so much that the light cannot escape. That said, the word “black” in this context refers to the effect of the object on its environment, not the color of the object itself. Since no information about the black hole object can escape to the outside, there is no way to learn the color or pigment of the object itself.

If gravity were weaker and the light could escape, the object wouldn’t appear black anymore so we’d need another name. In fact, there are other astronomical objects that are very dense but not as dense as a black hole – we call them neutron stars.

posted on Thu, 07/12/2012 - 12:46pm
catluver  's picture
catluver says:

Do you work on building rocket ships or help disign the rocket? Is it worrying to go into outerspace?

posted on Fri, 06/29/2012 - 4:06pm
James Flaten's picture
James Flaten says:

I’m currently more involved in building science payloads to fly on balloons and NASA suborbital rockets, so I don’t claim to have much experience designing and building rockets yet. But that is something I hope to learn to do in near the future, starting by attending a workshop on high-power rocketry (the next step up from model rocketry) next week at NASA’s Marshall Space Flight Center in Huntsville, Alabama. Then during this coming school year I hope to be more involved in building and flying high-power rockets, and teaching students at the U of MN to do so as well.

For comments about worrying about going to outer space, see my answer to the question (below) about “being scared.”

posted on Thu, 07/12/2012 - 12:47pm
Callahan's picture
Callahan says:

Why is the average age of an astronaut 30 - 40? Is this because of training? I would think a younger and fitter person would do better in space due to the physical requirements of take off/ landing and working outside the shuttle.

posted on Mon, 07/02/2012 - 10:33am
James Flaten's picture
James Flaten says:

Flying in space isn’t in fact particularly strenuous, so astronauts do need to be reasonably fit but don’t necessarily need to be young/athletic. Astronaut training doesn’t take that long either (perhaps a couple of years, but then you may need to wait for a flight opportunity), so the average age isn’t because people start young and need to train for a decade or more. Instead, NASA has found that the people often don’t have the right skills, experience, maturity, judgment, etc. until they are in their 30’s and 40’s. A given astronaut usually only has a few flight opportunities, so astronauts tend to be reassigned to ground duties (or retire and go on to a different career, sometimes in education promoting interest in space) before they are into their 50’s.

posted on Thu, 07/12/2012 - 12:48pm
 DAYTON!'s picture
DAYTON! says:

is it true that black holes suck up debris,and white holes shoot it out??????

posted on Mon, 07/02/2012 - 3:05pm
James Flaten's picture
James Flaten says:

Einstein’s General Theory of Relativity allows for “black holes,” into which matter and light can fall and never emerge, as well as “white holes,” from which both matter and light could technically emerge. Black holes can be formed by gravitational collapse of stars but there is no known astronomical mechanism to form a white hole so, as far as I know, astronomers don’t actually believe they exist. They just aren’t disallowed by our understanding of physics.

posted on Thu, 07/12/2012 - 12:48pm
Jonah's picture
Jonah says:

How exactly do spaceships fly?

How long does it take to get to the moon now? I know it used to be 6 days.

posted on Mon, 07/02/2012 - 3:35pm
James Flaten's picture
James Flaten says:

See earlier comments about rocket engines. Simply stated, rocket engines propel a spacecraft to a specific speed but once the engines are shut down the spacecraft continues along at that speed, possibly deflected by gravity as it passes other objects, because there is no air in outer space to slow it down.

The distance to the Moon ranges from about 350,000 to 400,000 km and the time it takes to get there depends on how fast you are traveling after launch (and how much you slow down due to the Earth pulling you backward as you try to get away). You need to reach an escape velocity of 11.2 km/sec (relative to the surface) to get away from the Earth, but if you only go that fast you will slow down before getting pulled in by the Moon, which might put an upper bound on the time it takes. The Apollo spacecraft took about 3 days to reach the Moon (and 3 days to return, which is perhaps where you are remembering 6 days from). Our highest-launch-speed spacecraft, New Horizons, passed the orbit of the Moon after only 6 hours, but it was heading in a different direction (to fly by Pluto).

posted on Thu, 07/12/2012 - 12:49pm
Clare's picture
Clare says:

Do the other planets' skies look the same as the sky does from earth?

posted on Tue, 07/03/2012 - 9:48am
James Flaten's picture
James Flaten says:

No. What we see in the daytime sky is strongly affected by the scattering of sunlight by the atmosphere, so blue light not originally heading toward us gets scattered in our direction and the whole sky appears blue (except in the direction of the Sun itself, which looks redder). Other planets have different atmospheres so the appearance of the daytime sky could look quite different. The sky as viewed from the surface of Mars, for example, looks red due to the presence of dust in the atmosphere (as opposed to blue due to Rayleigh scattering). From Mercury and the Moon, which have essentially no atmosphere, the sky looks black even in the daytime. We see the blackness of space at night since our atmosphere is transparent, when it isn’t “glowing” due to scattered sunlight.

Here is a website to learn more: http://en.wikipedia.org/wiki/Extraterrestrial_skies

posted on Thu, 07/12/2012 - 12:49pm
caleb fetzer's picture
caleb fetzer says:

what is the moons surface made of

posted on Wed, 07/04/2012 - 2:18pm
James Flaten's picture
James Flaten says:

The lunar surface is broadly classified into light-colored “highlands” and dark-colored “maria” (Latin for “sea” – hence the “sea of Tranquility” etc.). Highlands tend to be mountainous and maria tend to be flat because they are areas that were filled in by basaltic lava flows long ago. There are a wide range of sizes of rock on the surface of the Moon, ranging from fine dust to boulders. The Apollo missions brought back moon rocks for study. Indeed, the first thing Neil Armstrong did when he first landed in Apollo 11 was to grab some moon rocks and put them in his pocket, just to be sure to have something to take back in case they had to leave abruptly. Strong similarities between the composition of lunar rocks and earth rocks supports the theory that the Moon was formed after a collision of a Mars-size object with the Earth.

posted on Thu, 07/12/2012 - 12:49pm
irene  shin's picture
irene shin says:

is it scary going to space? do you like it?

posted on Wed, 07/04/2012 - 3:16pm
James Flaten's picture
James Flaten says:

Outer space is indeed a hostile place, with no air to breathe and lots of cosmic radiation. However if you have the appropriate equipment (a spacesuit) to protect you and provide you air to breath, it isn’t necessarily a place to be scared of. Indeed, people who have been to outer space do say they like it.

I haven’t personally gone into outer space, but I’ve sent things there and if they could talk I think they would tell me that going there and being there was fine (but coming back down, 20 miles by parachute, might have been scary). :)

posted on Thu, 07/12/2012 - 12:50pm
jimmy's picture
jimmy says:

is it cool being in space

posted on Fri, 07/06/2012 - 3:58pm
James Flaten's picture
James Flaten says:

I haven’t been in outer space myself but I’ve met quite a few astronauts and every one of them says that being in space is cool. Of course, they are a self-selected group of people who wanted to go. But even so, space continues to have appeal to all ages and all sorts of people and I look forward to a future where more and more people have the opportunity to experience it firsthand.

posted on Thu, 07/12/2012 - 12:50pm
HERBERT's picture


posted on Fri, 07/13/2012 - 10:59am
dakota's picture
dakota says:

i have always wanted to go in to space as a kid and i still do i love space

posted on Sat, 07/21/2012 - 4:01pm
JQA forever's picture
JQA forever says:

What advice do you have for an aspiring engineer with an aptitude for mathematics and science?

posted on Sun, 08/05/2012 - 6:43pm
HERMAN500's picture
HERMAN500 says:

What can you do on Earth that you can't do in space?
2. What is your assesment of string theories?

posted on Wed, 08/08/2012 - 4:44pm
1d's picture
1d says:

how old was niell armstong when he went to space

posted on Tue, 08/28/2012 - 12:42pm
asdjkhafhfdlksa's picture
asdjkhafhfdlksa says:

approximately how much would it cost to build a small space ship that can hold 2-3 people. There is no major cargo, just resouces to sustain life for 3 days like water food. Also what other things would you need to live for 3 days aboard the space shuttle mentioned above.

posted on Fri, 09/14/2012 - 10:49pm
Akaysha's picture
Akaysha says:

what do you do in space and how can you keep ocupied

posted on Sat, 10/06/2012 - 3:15pm
Akaysha's picture
Akaysha says:

i think space could kinda be fun but id get board

posted on Sat, 10/06/2012 - 3:16pm
Akaysha's picture
Akaysha says:

what do astronaunts do on their spare time?

posted on Sat, 10/06/2012 - 3:18pm
greta 's picture
greta says:

why is there no gravity in outer space??????

posted on Fri, 11/16/2012 - 12:42pm
Jake Hutchins's picture
Jake Hutchins says:

Do you eat astronaut icecream?

posted on Sun, 11/18/2012 - 1:53pm
evan's picture
evan says:

Hello. Please tell me, how do rockets fly?

posted on Sat, 12/29/2012 - 7:06pm
abyyah's picture
abyyah says:

did your group meaurd a planet

posted on Tue, 01/01/2013 - 3:39pm