Space Elevators and Astronomy

By Andy Darnley

Imagine riding in a cabin going roughly 200 miles per hour, with the clouds rushing past. After five to six days, you stop seeing blue skies outside your window, and instead see the curvature of the Earth’s surface amid deep black space. No, it’s not an airplane or rocket you’re riding on, but a space elevator. Space elevators, vehicles designed to take us in and out of space using a cable instead of rockets, have been talked about by scientists for centuries, and are coming closer and closer to becoming a reality.

What Is a Space Elevator?

A space elevator is a proposed transportation system designed to take satellites, space stations, or even people beyond Earth’s atmosphere and into space. The design would consist of a strong but thin cable or tether anchored to the Earth, extending beyond Earth’s gravitational pull. A vehicle, or “climber,†would move up and down the tether, into and back down from space. To work, the cable would need to be anchored near the Earth’s equator. From the outside, it would appear that the Earth is a ball with a long string or stick extending from it.

The tether would remain stationary, held down by a base station. Scientists, so far, think the best location for the base of the elevator would be in the Pacific Ocean near the equator. The rotation of the Earth combined with Earth’s gravity and the centrifugal force pulling outward and upward beyond its atmosphere would make sure the ribbon stays stretched and does not fall. The elevator would need to be thickest just above where Earth’s atmosphere ends and space begin. This is called Earth’s geostationary orbit, and the thickest, heaviest part would be the “center of massâ€-in physics, that’s where a system balances forces equally from each side.

Space elevators have been talked about since the late 19th century, when the scientist Konstantin Tsiolkovsky first had the idea. Since then, the concept has been further explored by other scientists and by NASA. One Japanese corporation thinks they may have the first space elevator built by 2035. The main challenge of creating one is constructing the ribbon, or tether. Researchers believe that the best option is to use a new technology called carbon nanotubes, carbon tube-shaped materials that are so narrow they measure on a nanometer scale, and aren’t visible to the human eye. These nanotubes would be both strong enough to hold large amounts of weight and light enough to be able to stretch into space.

Why would we want to have a space elevator? Right now, it is extremely expensive to launch anything into space. Millions of dollars and tons of fuel are required for each trip. With a space elevator, trips into space could become both more routine and less costly. The carrier could be launched once per day. The cost per pound to send people or things to space would drop from over $20,000 per pound to around $500 per pound. It would make travel into space a more commonplace event, much like the advance of railroads and airplanes made cross-country travel possible when it was once very inaccessible.

• NASA and the Space Elevator
• The Space Elevator Could Soon Be a Reality
• NOVA: Space Elevator
• Audacious and Outrageous: Space Elevators

More Information on Space Elevators

Although the concept of the space elevator sound simple, we still have quite a way to go to be able to create the first one. Some of the technology needed simply does not yet exist. Before more progress can be made, scientists must figure out how to create a carbon nanotube ribbon long enough to reach into space – that’s about 62,000 miles. The longest carbon nanotube created to date only measures about 1 meter! Other challenges include cost and legal issues-before constructing space elevators, scientists have to get permission from the government of the country where they will build it. Below are more resources about space elevators and the progress that is being made toward constructing the first one.

• New Diamond Nanothreads May Make Space Elevators a Reality
• The Space Elevator: Lesson Plan
• The Physics of the Space Elevator
• Universe Today: What Is a Space Elevator?
• Can Quiet, Efficient Space Elevators Really Work?
• Carbon Nanotubes
• Long, Stretchy Carbon Nanotubes Could Make Space Elevators Possible
• The Future of Space Travel

Astronomy Resources

Astronomy is the study of space and the worlds around us. Astronomers examine the space beyond Earth, to our solar system, our galaxy, and beyond. They use many tools such as telescopes, satellites, math, and physics to learn more about the universe and our relationship to it.

When talking about astronomy, some of the main topics you will learn about are our solar system, which Earth is a part of; our galaxy, which our solar system is a part of; and the universe, which encompasses all of space as we know it. You may discuss the stars, which are balls of fire made up of burning gases, or comets and asteroids, which are fragments of rock in space. The eight planets of our solar system revolve around the sun, which is a bright star that provides the warmth and energy that make life possible on earth. Our solar system is just one of many in the galaxy called the Milky Way, and the Milky Way is just one of many galaxies in the universe.

Astronomers have discovered a remarkable amount of information about our universe. We now have a sense of how small Earth is compared to what else is out there. With the invention of the space elevator getting closer to becoming a reality, we may be well on our way to knowing even more about space. Below are resources to find out even more about the universe around us.

• Star Word Search
• Game: Solar System Scoot
• Mag 7 Star Charts
• Stellarium: Free Planetarium for Your Computer
• Solar System Trading Cards
• The Nine Planets
• Cosmos4Kids: The Sun
• Planets and the Solar System Misconceptions
• What Color Is Each Planet?
• Solar System Fact Sheet
• Moonstruck! Does The Full Moon Influence Behavior?
• The Moon
• The Smithsonian: Dwarf Planets
• FAQ: Dwarf Planets
• Why Isn’t Pluto a Planet?
• Exploring the Moon: Activities for Earth and Space Sciences
• Living in the Milky Way Worksheet
• Comets: Learn the Facts