Activity #1: "Air Pressure in Action"

Just what is air pressure? How strong a force do you think air pressure is? Do you think you could lift a person with just air? Try it!

Here's what you need:

Do this:

1. Cut the end of several plastic straws at an angle so it will penetrate the trash bag easily.
   
2. Spread the bag out over the floor or a large table and have students quickly jab their straws into the bag, around the edge of the bag. Tape the straws in to minimize air leaks.
   
3. Have someone sit or lay on the trash bag while the others blow into their straws. Be careful not to blow too hard or overexert yourself!! See if you can lift your buddy off the floor.
   
4. Write down what you see.

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Activity #2: "Air Pressure Can Crusher"

In an empty pop can, there is air pressure inside of it and also outside of it, both pushing against each other. The forces balance out. What if we could take a pop can and get rid of the air pressure inside? What do you think would happen? Be careful heating the pop can in this activity - be sure to have a parent or teacher working with you.

Here's what you need:

Do this:

1. Caution: you must be careful around a source of heat such as the hot plate or Bunsen burner!
   
2. Put a very small amount of water in the empty pop can; just enough to cover the bottom.
   
3. Put the can on the heat source and wait until you can see steam rising from the can opening.
   
4. Using the tongs, quickly pull the can off the heat source and push it, open end first, into the tub of water. The can should immediately crush. Each student may crush his or her own can.

Other stuff to do:

1. What sort of can crushes the best? Does a tin can make a louder sound?
   
2. Vary the amount of water in the can. See who can make the loudest noise.
   
3. Can you write down what makes the pop can go kaboom?

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Activity #3: "Why are Space Suits Always White?"

One of the problems of working outside of the shuttle is maintaining a comfortable temperature. It can be very warm in the sunlight and also cold in the darkness, in the shadow of the Sun. Space suits are white for the same reason that we like to wear white clothing in the summer time. Lets see how much this makes a difference.

Here's what you need:

Do this:

1. Cut the construction paper into 4-inch squares, both black and white, and tape a piece around the bulb of a thermometer. Be very careful not to bend the thermometer or break it! This can be done in teams if there are enough thermometers.
   
2. Have a student be the timer and announce the time at one minute intervals for five minutes. Others can read the thermometers and record their readings.
   
3. Now take the students out of doors and repeat #2. What is the difference in temperature? Why is there a difference?

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Activity #4: The Effect of Space Debris

Space is filled with debris. Sometimes we see some of this debris when we see a "shooting star," or meteor. Meteors are dust grains the size of pinheads that burn up due to friction with the atmosphere roughly 25-30 miles above the ground. Our atmosphere might be struck by close to a million of these small bits daily but they are no danger to those of us on the Earth's surface. In space, the atmosphere offers us no protection!

You might think that something no larger than a pencil eraser wouldn't hurt us, but these particles are traveling in space at speeds up to 20,000 miles per hour! Something that small at that speed could travel right through an astronaut unless precautions are taken. Part of the space suit is a Kevlar lining, the same substance that police officers wear in bulletproof vests.

Particles this small can pit or sandblast the spacecraft, but they do not penetrate. Larger bits of debris, such as the leftover junk from previous launches, are more hazardous. This is something the designers of a future space habitat must consider! Most satellites currently have double-walled shields to assist in protection. When working in space, astronauts must be careful not to leave a loose nut or bolt. These are potential hazards to future missions.

In this activity you'll see how something at high speed can do more damage than something at low speed.

Here's what you need:

Do this:

1. Hand out straws and raw potatoes to each student or to groups of students.
   
2. Can you put the straw into the potato! Caution: Be sure your hands are out of the way of the straw!
   
3. Does it make a difference how fast you push the straw into the potato? Try different speeds. Which speed is best, fast or slow?

Other stuff to do:

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Activity #5: "Cooling Your Hand"

We sweat to cool ourselves off when we are warm. The water from our skin evaporates and carries heat with it. Removing heat is a cooling effect. You also notice this when you get out of the swimming pool on a hot day. The water evaporating from your skin makes you feel cool. The shuttle astronauts don't dip their bodies into water, naturally, but they do run water near their skin by way of about 300-feet of tubing. The water is chilled, thus promoting heat transfer.

Here's what you need:    Bowl of water

Do this:

1. Dip your hands into a bowl of water and then pull it out. What do you feel?
   
2. A fan could be used to blow air over your hands. Why do they feel cooler? As the water evaporates and the hand dries, does it still feel as cool? What do you think is happening here?

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Activity #6: Using Space Tools

So . . . you think you can wear a space suit and work in space? Today's space shuttle gloves are an improvement over the pressurized gloves that went to the Moon. Our lunar astronauts had problems with the gloves being inflexible and hurting their hands. Today's gloves were designed for comfort, but this is still difficult as the gloves (and the rest of the spacesuit) are pressurized just like a balloon. Small tools can be difficult to use and normally simple tasks become more cumbersome when in the spacesuit. Give it a try!

Here's what you need:

Do this:

1. Put on the gloves and share the tools with your buddies.
   
2. Try to complete such tasks as writing your name, wiring a wire to a lamp plug, building a structure out of blocks, putting a nut on a bolt, using a wrench to tighten or loosen a nut.
   
3. Discuss and record what tasks are easy and which are more difficult.

Other stuff to do:

1. How could some of the tasks performed be completed easier? Designed some tools that would work more efficiently with the thick gloves.
   
2. Design a project to be done in space where some of these tasks would need to be performed.

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Activity #7: "How Much Oxygen Will We Need in Space?"

A space-walking astronaut must have an adequate supply of air (oxygen) to breathe. A spacesuit will normally supply about 6-7 hours of oxygen, but this naturally depends on the rate at which it is used. In this activity, you will determine the amount of air you use during rest and during physical activity. From this data, one may calculate the amount of oxygen needed for a six hour space walk.

Here's what you need:

Do this:

1. Calibrate the glass or plastic jug in units of liters. Pour one liter of water into the jug (you could also use a one liter soda pop container) and mark the level on the side of the jug with the marker. Add a second liter and continue until the jug is full.
   
2. Completely fill the jug with water and invert it into the basin of water so that air pressure causes the water to remain in the jug. Why the water doesn't run out of the bottle?
   
3. Insert one end of the tube into the end of the jug and carefully put the other end in your mouth. Exhale through the tube into the jug. Water will be displaced from the jug. Breathe normally and not blow into the tube. This is the toughest part!
   
4. Count how many breathes it takes to empty the water from the bottle. Also, determine the number of breaths you take during one minute using the stopwatch. Record the two measurements in the chart. Caution: Be sure to disinfect the end of the tube if someone else is going to use it!
   
5. The experiment can be repeated, but this time engage in some sort of physical activity for one minute before exhaling in the tube. Running in place is sufficient.
   
6. Calculate averages for each of the columns in the chart. Use the first two columns to determine the volume of air (in liters) an average student consumes per minute of normal activity and then repeat for strenuous activity.
   
7. Then calculate how much air our student astronauts will require for a six hour spacewalk, which may involve a mixture of light and heavy exertion.

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Activity #8: "Why Add Water to Food?"

The expense of launching items into orbit is building up enough thrust to boost the weight of the shuttle into orbit against the pull of gravity. The less weight we have to boost, the better off we are. What could we do to the shuttle to reduce its weight. What materials are lighter than others?

When dealing with food, it's easy to take the water out of a food items and then to rehydrate it in orbit. Water is a by-product of the space shuttle fuel cells, meaning water is plentiful in orbit. You should realize how much weight is added to a food item when it contains water.

Here's what you need:

Do this:

1. Carefully weigh the apple on a balance. Record all measurements.
   
2. Now cut the apple into thin slices. Use caution with the knife!
   
3. Put the slices on aluminum foil and place the pieces in a sunny window to dry.
   
4. Re-weigh all the apple parts together the next day. Calculate the difference in weight. Do the dried apples weigh more or less? Why?

Other stuff to do:

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Activity #9: "Why are the Space Suit's Controls Labeled Backwards?

The astronaut in the space suit cannot see the controls on his or her chest pack due to the helmet. Therefore, there is a mirror on the forearm of the suit where the astronaut can view the image of the pack controls. The labels on the controls have to be written backwards so that they will be able to be read by the astronaut.

Here's what you need:

Do this:

1. Take the mirror and try to write your name backwards by looking at what you are writing in the mirror. Write a message to a friend using the mirror.
   
2. Tape your message to your chest and try to read it without bending over. Can you do it?
   
3. Hold your mirror with one hand in front of you. Can you read it now?

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Activity #10: Moving Around in a Spacesuit

Remember the importance of oxygen pressure from an earlier part of the web page. Pressure is vital for survival! However, a problem arises when supplying this needed pressure. How can we move around in a space suit when it is inflated just like a balloon? The walls of the suit will stiffen as pressure increases and the astronaut becomes immobile.

Here's what you need:

Do this:

1. Inflate one of the balloons and tie the end. Get some help with this if you need it. String can be used to secure the end so no air escapes.
   
2. Bend the balloon in half or in thirds. Is it easy? What are the implications for space suit use? Remember that you are modeling a space suit so it is not in your best interest to attempt to break the balloon!
   
3. Inflate a second balloon. While it is inflating, slide the thick rubber bands over the balloon so the finished balloon looks like sausage links.
   
4. Compare the "bendability" of each balloon. Which is easier to bend? Why? Write down your observations.

Other stuff to do:

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Activity #11: Microgravity Demonstrator

Be careful using the term "Zero-G." This implies there is no gravity, which is not the case! When you see an astronaut apparently floating in the shuttle, the obvious explanation is that there's no gravity. Astronauts appear to float in the space shuttle because they are falling (or "are in free-fall") at the same rate as the space shuttle. They are falling together under the influence of the Earth's gravity. If the can or cup in this demonstration falls in the Earth's gravity and the water inside the can falls at the same rate, the water in the can seems to "float" inside the can just as the astronauts do. This has been called "weightlessness" though microgravity is now the preferred term.

Here's what you need:

Do this:

1. Punch a hole in the side of the cup/can near the bottom.
   
2. Hold your thumb over the hole and fill the container with water. What will happen if you take your thumb off the hole?
   
3. Refill the container with your thumb over the hole and gain as much altitude as you can, but standing on a desk or chair next to the catch basin.
   
4. Make a prediction as to what you will see when you take your thumb off the hole but drop the can into the basin. What's happening here? Write down what you see and your predictions!

Other stuff to do:

1. A further activity can be constructed by lowering an object on a wire into a two liter bottle and then holding the wire and two liter bottle high above the ground. If you drop both at the same time the object could be seen to "float" inside the bottle.
   
2. Velcro your pencils to the desk "so they won't float away!"
   

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