Since the dawn of the space age, climbing toward the stars has required a breathtaking amount of rocket fuel, making trips into space both expensive and dangerous.
Science fiction is the province of big dreams, and few dreams are bigger than our planet's very own stairway to heaven, the space elevator. This grand idea offers the promise of safe, inexpensive trips into orbit (and back!) on a daily basis. The space elevator was popularized by science fiction author Arthur C. Clarke in the novel Fountains of Paradise, and also plays a bit part in this month's book selection, Old Man's War.
The most surprising part of the idea: it's not as crazy as it sounds.
Jack and the GEO-Beanstalk
So how does it work? An anchor would be positioned in geostationary orbit, then connected to a base platform on Earth using a ribbon of ultra-strong carbon nanotubes. Mechanical lifters would climb up and down the ribbon, dropping the cost from today's $20,000 per kilogram to perhaps $100/kg. From How Stuff Works:
To better understand the concept of a space elevator, think of the game tetherball in which a rope is attached at one end to a pole and at the other to a ball. In this analogy, the rope is the carbon nanotubes composite ribbon, the pole is the Earth and the ball is the counterweight. Now, imagine the ball is placed in perpetual spin around the pole, so fast that it keeps the rope taut. This is the general idea of the space elevator. The counterweight spins around the Earth, keeping the cable straight and allowing the robotic lifters to ride up and down the ribbon.
Here's a short space elevator video (< 2 min.) to demonstrate the basic principles:
Why on Earth do we need one? Construction of a space elevator would be a monumental undertaking, in terms of time as well as cost. So what benefits would we see from one? Here are some broad categories, from the frivolous to weighty:
- Entertainment & tourism. With multi-millionaires paying exorbitant fees to spend a few days on the cramped space station, space tourism is a no-brainer. There'd be incredible sightseeing, of course, but how about a null-gravity Olympics? Or a real-life version of the Battle Room from Ender's Game?
- Resource exploitation. Should it suddenly become trivial to move equipment and materials up and down the gravity well, then the near solar system (the Moon, asteroid belt, etc.) is suddenly ripe with possibilities. And how about a research station with 24 hour access to solar energy...
- Entrepreneurial innovation. Today's system of global commerce is largely the outgrowth of the trans-continental rail and highway systems. Who knows what might happen if we apply the free market engines of creation to the orbital plane? A space elevator could realign our relationship with outer space and transform the global economy.
- Exploration & colonization. During NASA's trips to the moon, the vast majority of the payload was spent on fuel for the outgoing and return journeys. It becomes far more economical to send probes to the moon, Mars, and beyond using the trip up the space elevator as a sort of slingshot.
Space tourism is sexy, and the commercial promise of a space elevator can help justify the cost to voters and/or shareholders. But at the end of the day, our place in the cosmos is a tenuous one. With 100% of our species trapped on a single planet, we are a single asteroid strike or global pandemic away from extinction. The best long-term case for the space elevator, simply put: if humanity is to endure, we must escape the tyranny of Earth's gravity well and begin to settle the stars.
Objects in future may be closer than they appearWhen asked when he thought the vision might become a reality, Arthur C. Clarke responded "fifty years after everyone stops laughing."
Luckily for the rest of us, a devoted cadre of scientists and engineers has not only stopped laughing, but dedicated their lives to making the space elevator a reality. A
Space Elevator Conference was recently held in in Redmond, WA; additional conferences are planned in
Japan and
Europe. There is also a space elevator
reference site, a space elevator
blog, and a space elevator
foundation.
The Bremerton, WA
Liftport Group is the most commercially ambitious of the lot, with a countdown clock on their Web site marking time until their tentative launch date of October 27, 2031. Their site also has a FAQ that includes a fascinating section on
potential threats to the space elevator such as space debris, extreme weather, and terrorism.
Would you like to know more? NOVA recently produced an informative and inspiring
special on the space elevator. The clip below is about ten minutes long, and includes footage from a recent
X-Prize event in New Mexico:
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Other posts on Book Club for Old Man's War, by John Scalzi:
by Cormac McCarthy. Posts about this book: