Humans in Space SPACE

Learning Goals To be able to explain how humans function in space

Feeling of Weightlessness Most people think weightlessness is caused by a lack of gravity The force of gravity 100 km above Earth’s surface is 97% of the force at Earth’s surface Weightlessness occurs because the astronauts are constantly falling towards Earth at the same rate as their spacecraft This affects the body and causes Space Adaptation Syndrome (SAS)

Effects on Humans Dizziness – about 2/3 of astronauts experience dizziness, disorientation, and nausea during their first few days due to constantly falling Important tasks such as space walks or docking with the ISS do not take place in the first few days so astronauts can adapt

Effects on Humans Puffy Face and Skinny Legs – on Earth, blood and other body fluids distribute evenly; when in orbit, these fluids collect in the upper parts of the body because of the constant falling motion This causes puffy face, stuffy nose, headaches, and legs to become skinny Space travel also affects the body’s use of water and can cause dehydration

Effects on Humans Bone and Muscle Loss – astronauts can lose up to 2% of their bone mass for each month spent in space This is because the skeletal system does not have to hold up their bodies and leads to a condition similar to osteoporosis Muscles also weaken so astronauts use a treadmill for at least 2 hours a day Astronauts can grow 2 to 4 cm because the backbone does not compress as much Readapting to Earth takes about as long as the astronaut was in space

Hazards in Space Radiation – Earth’s atmosphere and magnetic field protects us from the Sun’s radiation In low Earth orbit, astronauts can be exposed to harmful radiation The Space Shuttle and spacesuits are designed with shields to protect astronauts On missions farther away from Earth, radiation exposure has to be monitored closely

Hazards in Space Environmental System Failure – life support systems are essential to maintaining the survival of astronauts Computer Failure – spacecraft are operated by computers; Space Shuttle has 5 computers that “vote” to make sure the correct decision is made Loss of Communication – Mission Control Center guides spacecraft through re-entry; “go home plan” is updated each day

Living in Space On the ISS, electricity is generated from solar panels Oxygen comes from electrolysis, breaking down water Water is recycled as much as possible Food is dehydrated (dried out) then rehydrated and heated in microwaves Astronauts use footholds to stay in place and are strapped down to floors, walls, or ceilings when sleeping

Working in Space Microgravity – an environment in which objects behave as though there is very little gravity affecting them Astronauts train in water tanks on Earth Tools must be precise and suited for 100°C environments with no air, and must be tethered to something with a long cord November 2008, an astronaut let go of a backpack sized tool bag worth $100,000, which was spotted in the night sky, now burned up

Technology Transfer – Why Go to Space? Canadarm technology is used in artificial limbs, to clean up harmful wastes, and to perform surgery (without leaving large incisions) GPS (Global Positioning System) – a network of 30 satellites orbit Earth; at least 4 satellites send signals to identify specific locations Many items were originally developed for use in space – bar codes, beverage coolers, cordless tools, lightweight shoes

Success Criteria I CAN describe how humans live and work in space I CAN describe some of the hazards human face in space