How long can humans survive in space?

1. How long can humans survive in space? By: Table 3 (Christopher Brown, Sarah Gonzalez, & Iris Buckner)

2. Firstly • We need oxygen to breathe. So if we go to live in space then we need to have some kind of sealed environment like a spacesuit or a space station. • This artificial environment must also be supplied with food water and oxygen constantly to maintain its survivability.

3. Secondly • We have to consider the effects of zero-G or zero gravity on the body. • Without gravity holding our organs relatively in place they float around in our bodies. • Without gravity the fluids in our bodies are not evenly distributed and they congregate in our upper body. • Weightlessness also causes bone and muscle deterioration because you don’t use these much in space. To counteract this astronauts exercise in a section of the ship that (when exercising properly) simulates gravity. • It also causes dizziness (or vertigo). To maintain balance, behind your eardrums in your inner ear, you have fluid in which are nerves that interpret the motion of the fluid to tell your brain which way is up. So when the fluid goes weightless your brain can’t tell which way is up and you become dizzy.

4. Continued… • Besides breathing our other bodily functions must also continue. • We still have to eat, sleep, use the bathroom, take showers, etc… • Luckily our esophagus still works in space, with the muscles pushing food down into our stomach to be digested. • The same is true later on down the line, those muscles still work too, but since everything is weightless astronauts have to use a special toilet in space. It doesn’t use water, it uses pressure differential to suck the waste out of the cabin. Urine goes through a water treatment system so it can be recycled, and solid waste is ejected from the vehicle.

5. Continued x2… • As far as showering goes astronauts use a special space shower that utilizes as little water as possible, but it is rarely used because it is uncomfortable and not very effective. • Well what about sleep? • To catch some zzz’s on a spaceship astronauts have to sleep in a sleeping bag that is strapped to the deck to keep them from floating off in their sleep!

6. What about… • The possibilities of a moon base or mars base? • Well all celestial bodies hold clues in or on them about the origins of our solar system. They are like windows into the past. Giving clues about what the solar system was like in its infancy. The cassini spacecraft found 63 moons orbiting Saturn. Imagine what we could learn form them. • And such bases would have other implications as well. For instance, the moon has less gravity, so if we used a moon base as a launching point for an intersystem mission, the rocket wouldn’t have to burn as much fuel to escape the gravitational pull. That means we could launch larger payloads from the moon or lnger distance missions

7. Wait! Problem! • What do you think happens to the spent rockets after they deliver their payload to orbit? • There are already 700+ operational satellites orbiting earth with countless other pieces of man made “space trash” that cause all kinds of navigational havoc to those operational ones. • So since nothing has been done to clean up space then what will eventually happen if the problem is left unsolved. • That’s right. Space will become so cluttered that launching new satellites and crews into orbit will become impossible due to navigational hazards.

8. Continued… • You wouldn’t think that debris can cause that much damage but one of the windows on the space shuttle was cracked by a fleck of paint from a defunct satellite.

9. Exploration • The sun is going to be around for several more billion years until it runs out of fuel, expands, and slowly engulfs the earth. • So this means we have plenty of time to go exploring for a new home before this happens. (Luckily for us). • The sun travels around the galaxy in an orbit (much like our planet orbits the sun)approximately every 250 million years. So if we want to explore the stars then instead of coming up with some kind of fancy trick to stock a spaceship with enough supplies for a 100+ year mission to another planet then we might as well just wait for the sun to bring us close to another star system.

10. Continued… • And even if we don’t want to wait around for another star system to come to us, we’ve still achieved a lot in the past 50 years alone in space travel, who knows where we will be in 100, 150, 200+ years. The only downside is money. • Although we need to be prepared, because the Earth’s biosphere is being threatened by greenhouse gasses, so we might need to start looking for a new home soon.

11. Money • President Bush had an outline of a 15+ year plan for future space exploration, one of the points was to end the very costly space shuttle program and begin a new cost effective space vehicle program. • The current government administration has since cut the funding of NASA forcing them to end the shuttle program without starting up a new space vehicle program. • All because of a lack of money the space program has recently ground to a halt. It will eventually get back off the ground again, when the economy recovers, but for now we must resort to the other space-capable countries (China & Russia) for ferrying our astronauts into space.

12. Works Cited Marshall, A. "Biotic Ethics." Wikipedia. WikimediaFoundation, 18 Aug. 2013. Web. 18 Sept. 2013. Williams, Lynda. "Irrational Dreams of Space Colonization." N.p., n.d. Web. 18 Sept. 2013. <http://www.scientainment.com/lwilliams_peacereview.pdf>. Leone, Daniel A., ed. Space Exploration. Farmington Hills: Greenhaven, 2005. Print.