To boldly go out of the airlock, astronauts need to look the part. Donning a spacesuit protects astronauts from the dangerous conditions just beyond our atmosphere.
The outer layer of NASA’s Extravehicular Mobility Unit spacesuit is built tough from a blend of three fabrics. One fabric is the same stuff used in bulletproof vests. It protects an astronaut from space dust – small particles zooming at very high speeds that can cause punctures. It is also waterproof and fire-resistant.
Tethers keep the astronaut attached to the spacecraft so they don’t float away. If they did, the astronaut could use their SAFER, a backpack thruster containing nitrogen gas that allows them to move in space using a small joystick.
The backpack also contains oxygen for breathing and removes carbon dioxide that is exhaled. Too much carbon dioxide, especially in a small space, can be poisonous.
Temperatures can get extremely cold in space. To stop astronauts becoming icicles, spacesuits are built with layers of insulation to keep body heat in like a human thermos. The gloves are also fitted with fingertip heaters.
As well as suits for spacewalking, NASA has bright ‘pumpkin suits’ used during launch and re-entry. They come in the fashionable colour ‘international orange’, which is recognised around the world as a colour to help rescuers. Equipped with a parachute, life raft and a flotation device, the pumpkin suits are designed for emergency situations.
Russian cosmonaut Sergey Ryazanskiy in a Russian Orlan spacesuit, is pictured during a session of extravehicular activity on the International Space Station. Image: NASA
Quiz questions
What is the larval stage of a frog called?
Which metal is used in galvanising to coat steel and prevent rusting?
How many ribs does a person typically have?
The standard definition of a second is measured using light from atoms of which element?
Where would you find the dwarf planet Ceres? Is it a) between Mars and Jupiter, b) between Jupiter and Saturn, or c) between Saturn and Uranus?
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Try this: Make a jelly optical fibre
Line a container with baking paper.
Add 2 tablespoons of gelatine powder to one and a half cups of boiling water. Stir to dissolve.
Pour the jelly mixture into the container and chill it in the fridge for 2 hours.
Take the jelly out of the fridge and cut it so it is flat on all sides. This block needs to be cut in half lengthways to make a strip.
In a darkened room, shine a laser pointer through the thin end of the strip of jelly and try bouncing the light off the sides.
Try lifting the jelly strip up. What happens to the light?
Safety: This activity involves boiling water and sharp knives. Never look directly at a laser pointer, because it can damage your eyes. Younger readers should ask an adult for help. For more information, head to the CSIRO Double Helix safety page.
You will need
Boiling water
Gelatine powder
Baking paper
Flat-bottomed container (at least 15 cm long)
Fridge
Sharp, non-serrated knife
Cutting board
Clear plastic, such as an overhead transparency
Black paper
Laser pointer
What to do
Add 2 tablespoons of gelatine powder to one and a half cups of boiling water. Stir to dissolve the powder. Let it rest a moment and pop any bubbles.
Line the flat-bottomed container with baking paper.
Pour in the mixture. It should be at least 1 cm deep. Repeat Step 1 if you need more jelly.
Chill the container for 2 hours in the fridge.
Remove the jelly from the container.
Cut a strip of jelly 2 cm wide, making it as flat and smooth as you can. It might help to first heat the knife under hot water.
Trim the edges so the strip is flat on all sides.
Put the plastic over the black paper and place the jelly strip on top of the plastic.
In a darkened room, shine a laser pointer through the thin end of the jelly strip.
Bend the jelly so one end is pointing up. What happens to the light?
With the jelly strip lying flat, try bouncing the light off the sides of the strip.
What’s happening?
When light waves move from the jelly to the air, the path of the light is bent, or refracted. Some of the light is reflected back into the jelly. If you get it just right, the light will hit the boundary at a critical angle and will bounce back without exiting the jelly. This is called total internal reflection.
The light is effectively trapped inside the jelly, allowing you to bend it and bounce it back and forth. Another way to bend light around corners is to use mirrors, like in submarine periscopes, which also make use of reflection.
Applications
Optical fibres use total internal reflection to keep light inside the glass core and stop it escaping into the environment. As you bend the jelly strip, you might notice the end is bright like a torch. Doctors use optical fibres called endoscopes to shine light inside the body, helping them to see.
Explore hidden underwater environments, from a tropical coral paradise to the icy waters around Antarctica. This photo gallery from the Sydney Morning Herald is a collection from National Geographic's David Doubilet.
Watch it!
A mooring is a long anchored line of scientific equipment and floats, deployed to collect data from the ocean. This animation explains how this equipment is used by Investigator, Australia’s new Marine National Facility research vessel which is arriving in Hobart next week.
Quiz answers
A tadpole is the larval stage of a frog.
Zinc is used in galvanising to prevent steel from rusting.
People typically have 24 ribs.
Caesium atoms are used for the standard definition of a second.
a) Ceres is found between Mars and Jupiter.
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