Manned Space Exploration

Manned Space ExplorationScientists use a variety of equipment and transportation methods to study space.

Are there advantages to manned space exploration over unmanned exploration?

Living in space for long periods of time requires precautions against the long-term effects on the human body by zero-G, low pressure, and cosmic rays.

How are the needs of astronauts in space different from their needs on earth? What is Needed to Support Life?Temperature due to proximity of the sun

Water

A usable atmosphereTrue of False?There is no gravity in space.

Mass and weight are the same.

Living in space has no effect on the human body. What type of spacecraft is best suited for human exploration?4How are the needs of astronauts in space different from their needs on earth?What is Needed?There are many factors that have to be considered when planning a space trip.

The type of equipment needed, manner of launch, and accommodations for humans in space are important to human safety.

The long term effects of living in space have not yet been fully understood.What is Needed?Before any human settlements on other planets can be established, scientists must solve many problems such as time needed to travel the huge distances in space, the radiation exposure, atmosphere composition, temperature extremes, and pressure changes on other planets. Problems With Traveling in SpaceThink about what you learned in the last lesson about how different the temperatures and atmospheres were on other celestial bodies.

The distance from the Sun affects how much solar radiation arrives at that planet or object.

Too much solar radiation can kill humans if they do not have protection from the radiation. Problems with Traveling In Space

Space is huge and the distances between objects are very great.

It is generally cold and dark.

Human sense to time and speed are not accurate.

Living in a small crowded area can lead to depression. Problems With Traveling in SpaceOrbiting in space creates a nearly weightless effect for humans. It is called microgravity.

You can experience microgravity by riding roller coasters or jumping on a trampoline or off a diving board.

It is the "free fall" period of these activities when the microgravity occurs and of course only lasts for a short period of time.

The shuttle is held in orbit by gravity as it falls around the Earth. The force of microgravity in the shuttle is 1 X 10-6 gravity, so objects appear to be floating. It is sometimes called zero gravity, but is more accurately named microgravity because it is so slight.

Problems with traveling in spaceSince weight is measured by the pull of gravity on a mass, and mass is the amount of matter in a substance, astronauts lose weight due to less gravity. They will also lose some muscle mass because they do not use them due to the lesser gravity in space.

If muscles are not used, they will wither.

Problems with traveling in spaceMicrogravity will also cause water to form a ball rather than a water drop shape or any other shape water can take. This can cause problems showering, perspiring, and drinking. Food is prepared differently and may taste different. Astronauts often request hot sauce and spice to improve the flavor of their food.

Problems with traveling in spaceSleeping is challenging in microgravity. Sleeping bags are strapped to the walls and astronauts must secure themselves within them.

The rhythmic beating of the heart will cause the head to bob, so the head must be restrained.

Problems with traveling in spaceProviding clean air supply, water supply, temperature control, and a way to take of waste must also be considered. Living in space is challenging!

Leaving EarthEffects of MicrogravityBonesIn microgravity, astronauts no longer walk to get to different parts of the spacecraft, they float. This means that the bones in the lower part of the body that typically bear weight the legs, hips and spine experience a significant decrease in load bearing.

This reduction leads to bone breakdown and a release of calcium, which is reabsorbed by the body, leaving the bone more brittle and weak.

The release of calcium can also increase the risk of kidney stone formation and bone fractures.

An astronaut can lose 1 to 1.5 percent of bone mass in the hip in one month.

On missions outside Earths orbit, radiation exposure may also impact bone loss.

Effects of MicrogravityMusclesExtended spaceflight results in less load on the leg muscles and on the backs muscles used for posture. As a result, the muscles can begin to weaken or atrophy, and this could lead to fall-related injuries and accidents during exploration missions. Astronauts currently exercise to help maintain their muscle mass, but nutritional interventions designed to reduce the muscle loss may one day be added as a complement to the exercise program.

Effects of MicrogravityFluid ShiftIn space, the body no longer experiences the downward pull of gravity that distributes the blood and other body fluids to the lower part of the body, especially the legs. The fluids are redistributed to the upper part of the body and away from the lower extremities. While in space, astronauts often have a puffy face due to this fluid shift and legs that are smaller in circumference. The fluid shift to the head can also lead to a feeling of congestion.

Effects of MicrogravityCardiovascular SystemAlthough the cardiovascular system generally functions well in space, the heart doesnt have to work as hard in the microgravity environment. Over time, this could lead to deconditioning and a decrease in the size of the heart. There is also a concern that space radiation may affect endothelial cells, the lining of blood vessels, which might initiate or accelerate coronary heart disease.

Effects of MicrogravityThe Spine: Taller in SpaceAstronauts get a bit taller in space. On Earth, the disks between the vertebrae of the spinal column are slightly compressed due to gravity. In space, that compression is no longer present causing the disks to expand. The result: the spine lengthens, and the astronaut is taller. One possible side effect is back pain that may be associated with the lengthening of the spine.

Effects of MicrogravityInner Ear and Balance SystemOn Earth, a complex, integrated set of neural circuits allows humans to maintain balance, stabilize vision and understand body orientation in terms of location and direction. The brain receives and interprets information from numerous sense organs, particularly in the eyes, inner ear vestibular organs and the deep senses from muscles and joints. In space, this pattern of information is changed. The inner ear, which is sensitive to gravity, no longer functions as designed. Early in the mission, astronauts can experience disorientation, space motion sickness and a loss of sense of direction. Upon return to Earth, they must readjust to Earths gravity and can experience problems standing up, stabilizing their gaze, walking and turning. These disturbances are more profound as the length of microgravity exposure increases. The changes can impact operational activities including approach and landing, docking, remote manipulation, extravehicular activity and post-landing normal and emergency egress.

Effects of MicrogravitySleep and PerformanceMany factors the loss of a 24-hour day/light cycle, a confined environment and work demands can impact an astronauts ability to work well in space. In addition, exploration crews will have to shift their body clocks from the Earth day/night cycle to that of their destination. Scientists hope to help the crew increase their alertness and reduce performance errors through improvements to spacecraft lighting, sleep schedules and the scheduling of work shifts.Space Suitshttp://web.mit.edu/16.00/www/aec/spacesuit.htmlSpace Foodhttp://www.nasa.gov/centers/johnson/pdf/167750main_FS_SpaceFood508c.pdfWaste ManagementHow do astronauts go to the bathroom in space?

It may sound silly, but its really a good question, because weightlessness does make a visit to the latrine a tricky proposition.

Weightlessness poses two main problems in the bathroom. The first is that an astronaut could drift away from the bowl at any time. However, there is a simple solution. The astronauts strap on thigh and foot restraints in order to go to the john!

Waste ManagementThe second dilemma is a bit more complicated. Here on earth, gravity assures that our waste falls downward, away from the body. However, under weightless conditions, body waste has the disconcerting tendency to hover close to wherever it exited the body. On the earliest space flights, astronauts had to tape a bag to their bodies to catch the waste, but that got pretty messy.

Waste ManagementToday, astronauts actually use flushing toilets, that actually flush with air, rather than water. First, the air flow draws the waste away from the body, then flushes it into storage tanks. All of the liquid waste from the spacecraft is stored together in a holding tank, which is periodically dumped overboard, where the liquid evaporates. Solid waste, on the other hand, goes into a container thats exposed to the vacuum of space. The vacuum completely dries out the solid waste, which is taken back to earth for disposal.

Waste Managementhttp://brainbites.nasa.gov/#/bathroom-in-spaceLiving and Working in Spacehttp://brainbites.nasa.gov/#/scratch-nose-in-spacesuitEating in Spacehttp://indianapublicmedia.org/amomentofscience/dining-in-space/SpacecraftWorking Under Waterhttp://brainbites.nasa.gov/#/astronauts-practice-underwater