What do I have to do to became an astronaut? (Submitted December 09, 1996)

The Question What do I have to do to became an astronaut? The Answer For this we can perhaps point you in the right direction. We do not know how far along you are in school now, so our suggestions might not be totally appropriate: In school from K-12: Work hard and get A's. These programs are very competitive, so it is important to do well in school (especially in math and science). You might also think about where you go to college. If you want to be pilot, you might think about going to one of the military academies (Air Force, Army, Navy), because they will teach you to fly. These have the advantage that they are free for you to attend and you will become an officer when you graduate. If you plan it correctly, you will be a pilot and get lots of flight experience and technical training. Most pilots are from a military background, while the mission specialists are usually civilians. To be a mission specialist, you will need some academic area of expertise. If you work on the development of detectors on satellites, this would be very helpful. We suggest that you apply for the NASA summer programs and pick a major and research projects in the Earth or Space sciences, or Engineering, that involve NASA missions. You might want to look at the NASA programs home page at: http://www.nasa.gov/centers/goddard/education/ so that you can apply for them when you become qualified. Once you have obtained your B.S. and the required amount of experience, you will need to apply to the astronaut training program. All we know about this program we learned from reading the home page at: http://www.jsc.nasa.gov/Bios/more.html We suggest that you read this home page now, and periodically in the future, so you can plan towards that goal. You will need both to fulfill the basic requirements and be better than many others who apply. Good luck, and we are sure that if you work hard toward this goal it will pay off for you in the long-run whatever you decide to do. Jonathan Keohane and Koji Mukai

for Imagine the Universe! Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See http://imagine.gsfc.nasa.gov/ask_astro/ask_an_astronomer.html for help on other astronomy Q&A services. Question ID: 961209a2

What kind underwear do astronauts wear to keep warm? (Submitted January 07, 1997)

The Question I have one silly question if you can respond to me. I am working in a Japanese cosmetic company, and our president plans to climb Mt. Everest this year. He is over 60, so he is worried about keeping his body temperature. He is wondering what kind of underwear astronauts wear to keep warm?? I checked the homepage of Star Child Team, and other homepages. They say astronauts wear same usual clothes inside, but how about outside of the shuttle?? The Answer We work on developing, building and analyzing data from detectors designed to observe X-rays and gamma-rays, and don't have expertise with human space flight. I did do some hunting around for information about the astronauts and didn't find anything specific about what they wear underneath their space suits. I think the suit itself probably provides the protection from extreme cold temperatures but I am not sure of this. You should submit your question to the Ask an Astronaut page. It can be found at http://www.kennedyspacecenter.com/Ask-an-Astronaut.aspx. Maybe you will get an answer from someone with first-hand experience! There is also a database of questions previously answered by astronauts: http://spaceflight.nasa.gov/feedback/expert/index.html. Regards,

Padi Boyd

for Imagine the Universe! Regards,Padi Boydfor Imagine the Universe! Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See http://imagine.gsfc.nasa.gov/ask_astro/ask_an_astronomer.html for help on other astronomy Q&A services. Question ID: 970107b

When astronauts are in space, do they get lonely? (Submitted February 28, 1997)

The Question When you are up in space, do you ever get lonely? The Answer Our Laboratory at NASA's Goddard Space Flight Center is interested in sources of X-ray and gamma-ray emission in our Universe. No one in our Laboratory has ever been into space. I can give you the following lead, however, to directly ask some of NASA's astronauts if they were ever lonely. Because of the extremely high volume of e-mail they would receive if their addresses were public, astronauts' e-mail addresses are restricted. However, you can write them at the following address: Astronaut Office/CB

NASA

Johnson Space Center

Houston, TX 77058

Good luck!

Regards,

Laura Whitlock Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See http://imagine.gsfc.nasa.gov/ask_astro/ask_an_astronomer.html for help on other astronomy Q&A services. Question ID: 970228d

How do astronauts go to the bathroom in space? (Submitted April 11, 1997)

The Question My first graders want to know, How do astronauts go to the bathroom in space? I think the potty chair is in place. Is this correct? The Answer We have come up with a number of answers to your question. We will let you, as the professional teacher, decide which is appropriate for your classroom and what is best left to the teachers lounge. I. The Official NASA pages: A. There is a nice space shuttle web page at: http://shuttle.nasa.gov/ Digging in there I found a Q&A Web page. Here's what it says: http://spaceflight.nasa.gov/shuttle/reference/faq/living.html 6. How do you take a bath, brush your teeth, and go to the bathroom in space? We do not have a bath or shower on the Shuttle, so we just wash off with wet washcloths, using soaps that you don't have to rinse off. When we brush our teeth, we can either swallow the toothpaste or spit it into a washcloth. Designing a toilet for zero-gravity is tougher. We use air flow to make the urine or feces go where we want, since gravity will not do it for us. You have to be more careful and think about what you are doing with the toilet in the Shuttle. B. Another colleague pointed out that Johnson Space Center is the home of the astronauts, and they have some web pages dealing with this issue too. (We really know little more than you do about the astronaut program -- but they do.) Their home page at: http://www.jsc.nasa.gov/ has links for KIDS, EDUCATORS, and more. I went to their page: http://www.jsc.nasa.gov/Bios/more.html and this is what I found: This used to be under the old FAQ at Spacelink. It has since been removed. 4. HOW DO ASTRONAUTS GO TO THE BATHROOM AND TAKE CARE OF OTHER PERSONAL HYGIENE? 4. HOW DO ASTRONAUTS GO TO THE BATHROOM AND TAKE CARE OF OTHER PERSONAL HYGIENE? Each Space Shuttle has a toilet that can be used by both men and women. Designed to be as much as possible like those on Earth, the units use flowing air instead of water to move waste through the system. Solid wastes are compressed and stored on-board, and then removed after landing. Waste water is vented to space, although future systems may recycle it. The air is filtered to remove odor and bacteria and then returned to the cabin. Astronauts brush their teeth just like they do on Earth. There is no shower on the Shuttle, so astronauts must make do with sponge baths until they return home. The toilet that was first flown aboard STS-54 is completely new in design and offers new and improved features: The new toilet features better hygiene, larger storage capacity, greater dependability, and an overall cost savings in maintenance. -The previous model had a 14-day capacity for storage of waste material. The new model has an unlimited storage capacity. -The new model features a cylinder system where a plastic bag is placed in the toilet before use. The bag is then sealed and is forced to the bottom of the cylinder after each use by a plunger attached to a lever. A new bag is then placed in the toilet for the next astronaut. When the cylinder is filled, it is replaced by a new cylinder. -The previous model relied on air flow to pull the waste to a holding tank. None of the waste was separated as it is now. The new system provides better hygiene conditions. There was no way to empty the old system. When it was full, it simply could hold no more waste materials. It had a 14 day capacity. -The new toilet also provides an odor-free environment. The old model did not. -The opening in the lid of the toilet was increased from 4" to 8", allowing for easier handling of the plastic storage bags. -The urine collection system was also improved. A newer type of fan system is being used to force the urine to a holding tank where it is periodically ejected into space, where it vaporizes. -The previous system had trouble with corrosion in the fan system. -The new toilet can be cleaned without removal from the orbiter at the completion of the mission, reducing the cost of servicing. -The previous system must be removed and sent to a company in Houston, Texas for servicing. I hope this helps. Sincerely, Jonathan Keohane and most all of the Ask an Astrophysicist Team

-- for Imagine the Universe! Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See http://imagine.gsfc.nasa.gov/ask_astro/ask_an_astronomer.html for help on other astronomy Q&A services. Question ID: 970411a

How would the unprotected human body react to the vacuum of outer space? (Submitted June 03, 1997)

The Question How would the unprotected human body react to the vacuum of outer space? Would it inflate to bursting? or would it not? or would just the interior gases hyperinflate? We are also relating this to short-term exposure only. This question primarily relates to the pressure differential problems. Temperature or radiation considerations would be interesting as well. The question arose out of a discussion of the movie 2001. When Dave "blew" himself into the airlock from the pod without a helmet, should he have "blown up" or is there "no difference" as shown in the movie correct? The Answer From the now extinct page http://medlib/jsc.nasa.gov/intro/vacuum.html: How long can a human live unprotected in space? If you don't try to hold your breath, exposure to space for half a minute or so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness. Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after ten seconds or so. At some point you lose consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes, you're dying. The limits are not really known. You do not explode and your blood does not boil because of the containing effect of your skin and circulatory system. You do not instantly freeze because, although the space environment is typically very cold, heat does not transfer away from a body quickly. Loss of consciousness occurs only after the body has depleted the supply of oxygen in the blood. If your skin is exposed to direct sunlight without any protection from its intense ultraviolet radiation, you can get a very bad sunburn. At NASA's Manned Spacecraft Center (now renamed Johnson Space Center) we had a test subject accidentally exposed to a near vacuum (less than 1 psi) in an incident involving a leaking space suit in a vacuum chamber back in '65. He remained conscious for about 14 seconds, which is about the time it takes for O2 deprived blood to go from the lungs to the brain. The suit probably did not reach a hard vacuum, and we began repressurizing the chamber within 15 seconds. The subject regained consciousness at around 15,000 feet equivalent altitude. The subject later reported that he could feel and hear the air leaking out, and his last conscious memory was of the water on his tongue beginning to boil. Aviation Week and Space Technology (02/13/95) printed a letter by Leonard Gordon which reported another vacuum-packed anecdote: "The experiment of exposing an unpressurized hand to near vacuum for a significant time while the pilot went about his business occurred in real life on Aug. 16, 1960. Joe Kittinger, during his ascent to 102,800 ft (19.5 miles) in an open gondola, lost pressurization of his right hand. He decided to continue the mission, and the hand became painful and useless as you would expect. However, once back to lower altitudes following his record-breaking parachute jump, the hand returned to normal." References: Frequently Asked Questions on sci.space.*/sci.astro The Effect on the Chimpanzee of Rapid Decompression to a Near Vacuum, Alfred G. Koestler ed., NASA CR-329 (Nov 1965). Experimental Animal Decompression to a Near Vacuum Environment, R.W. Bancroft, J.E. Dunn, eds, Report SAM-TR-65-48 (June 1965), USAF School of Aerospace Medicine, Brooks AFB, Texas. Survival Under Near-Vacuum Conditions in the article "Barometric Pressure," by C.E. Billings, Chapter 1 of Bioastronautics Data Book, Second edition, NASA SP-3006, edited by James F. Parker Jr. and Vita R. West, 1973. Personal communication, James Skipper, NASA/JSC Crew Systems Division, December 14, 1994. Henry Spencer wrote the following for the sci.space FAQ: How Long Can a Human Live Unprotected in Space? If you *don't* try to hold your breath, exposure to space for half a minute of so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness. Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after 10 seconds or so. At some point you lose consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes you're dying. The limits are not really known. References: The Effect on the Chimpanzee of Rapid Decompression to a Near Vacuum , Alfred G. Koestler ed., NASA CR-329 (Nov. 1965) Experimental Animal Decompression to a Near Vacuum Environment , R.W. Bancroft, J.E. Dunn, eds, Report SAM-TR-65-48 (June 1965), USAF School of Aerospace Medicine, Brooks AFB, Texas. You would probably pass out in around 15 seconds because your lungs are now exchanging oxygen out of the blood. The reason that a human does not burst is that our skin has some strength. For instance compressed oxygen in a steel tank may be at several hundreds times the pressure of the air outside and the strength of the steel keeps the cylinder from breaking. Although our skin is not steel, it still is strong enough to keep our bodies from bursting in space. Also, the vapor pressure of water at 37 C is 47 mm Hg. As long as you keep your blood-pressure above that (which you will unless you go deep into shock) your blood will not boil. My guess is that the body seems to regulate blood pressure as a gauge, rather than absolute pressure (e.g. your blood vessels don't collapse when you dive 10 feet into a pool). The saliva on your tongue might boil, however. For more information and references, see http://www.sff.net/people/geoffrey.landis/vacuum.html Hope this helps!

The Ask an Astrophysicist Team Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See http://imagine.gsfc.nasa.gov/ask_astro/ask_an_astronomer.html for help on other astronomy Q&A services. Question ID: 970603

What danger does solar or cosmic radiation pose to astronauts? (Submitted January 19, 1998)

The Question I am curious to know what the effects of solar radiation have on space craft after they leave the protection of the Van Allen belt. How much protection do they need and how long could an astronaut survive in and out of his craft. The Answer Solar radiation and cosmic radiation are both things to worry about in space. The ultraviolet (UV) radiation from the Sun (without our protective ozone layer and atmosphere to protect us) would be enough to rapidly give you sunburn, melanoma, etc. However, unless your spacesuit or spacecraft windows are specifically designed to let UV pass through, enough will be blocked that you don't have to worry about it too much. (If you are in space without a spacesuit or spacecraft, then you've got bigger problems than radiation.) When the Sun flares, it produces x-rays, gamma-rays, and energetic particles. The energetic particles are the worst, but they are delayed compared to the X-rays and gamma-rays, so you have some warning that they are coming. This gives you time to get into a 'storm shelter', a well-shielded area that you can live in for a few days until the particles die down. A good place for a storm shelter would be in the center of the ship, surrounded by the water tanks. If you don't have a storm shelter (e.g. if you are out moonwalking in just your suit) a bad solar flare can kill you by radiation sickness. The hard radiation (particles and x/gamma rays) from the non-flaring Sun is small compared to the galactic cosmic ray exposure. These particles come from deep space more or less continuously. Small amounts of shielding can cut out the majority of this, but the remainder will give you a somewhat increased risk of cancer. Using very conservative rules of thumb, a week in space's cosmic ray environment will shorten your life expectancy by about a day (statistically--it is very unlikely to give you cancer, but if it does, it will shorten your life by more than a day). Since space is inherently dangerous at the present state of the art, cancer due to cosmic rays is relatively small additional risk. David Palmer

for Ask an Astrophysicist Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See http://imagine.gsfc.nasa.gov/ask_astro/ask_an_astronomer.html for help on other astronomy Q&A services. Question ID: 980119b

How is it possible for manned space flights to survive the effects of the Van Allen Radiation Belt? (Submitted June 30, 1997)

The Question How is it possible for manned space flights to survive the effects of the Van Allen Radiation Belt? The Answer As you know, the Van Allen radiation belts are doughnut-shaped regions encircling Earth and containing high-energy electrons and ions trapped in the Earth's magnetic field. Explorer I, launched by NASA in 1958, discovered these two regions of intense radiation surrounding the Earth. They are referred to as the inner and outer Van Allen radiation belts, after James Van Allen who designed Explorer I. The inner region is centered at about 3000 km above Earth and has a thickness of about 5000 km. The outer region is centered at about 15,000 -- 20,000 km above the surface of the Earth and has a thickness of 6,000 -- 10,000 km. Typically, manned space flight (such as the Shuttle) stays well below the altitude of the van Allen radiation belts. Safe flight can occur below altitudes of 400 km or so. SO ...what do we do when we have to fly through the radiation belts -- like when we went to the Moon or send probes to other planets? In the 1960s, NASA asked Oak Ridge National Laboratory to predict how astronauts and other materials would be affected by exposure to both the Earth's Van Allen radiation belts and the Sun's radiation. Oak Ridge biologists sent bacteria and blood samples into space and exposed small animals to radiation. They concluded that proper shielding would be key to successful flight not only for living organisms, but for electronic instrumentation as well. To develop shielding for the Apollo crews, Oak Ridge researchers recycled the Lab's Tower Shielding Facility, which had hoisted shielding experiments aloft for the 1950's nuclear-plane project. Regards,

Laura Whitlock

for Ask an Astrophysicist Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See http://imagine.gsfc.nasa.gov/ask_astro/ask_an_astronomer.html for help on other astronomy Q&A services. Question ID: 970630a

How are the cosmonauts in MIR protected from Ultraviolet, X-Rays and Gamma-rays? (Submitted August 04, 1997)