The Space Elevator: Not Just Science Fiction

Posted: March 6th, 2009 | Author: Steve | Filed under: Technology | Tags: IFTF, linkedin, Science, space, space elevator | View Comments

The appropriately-named Institue for the Future, a future forecasting and trend research think tank, held its first co-working session last Friday, and I jumped on the chance to attend. Not only have I been looking for good places to co-work, so I can be around intelligent, like-minded people, but I am a big fan of IFTF, which is one of two organizations in the Bay area dedicated to helping companies navigate the future (the other being Global Business Network). And, if you know me…I’m all about the future.

The event was hosted by Sean Ness, Business Development Manager and the Institute’s Twitter voice. Sean welcomed a diverse group of really interesting people, including Matt Everingham from the California Space Authority. It turns out that Matt works with NASA’s Centennial Challenges program, which “was established to conduct prize competitions in support of the Vision for Space Exploration and ongoing NASA programs.” These challenges are similar to the ANSARI X PRIZE, won by Burt Rutan, which encouraged the first-ever private suborbital space flight. NASA is currently hosting several of these challenges, including the Tether and Power Beam Challenges, both of which are designed to support development of a space elevator, which could be called the “holy grail” of space launch platforms.

Being the geeks-at-heart that we are, this lead to a lively discussion about the likelihood and feasibility of a space elevator. While I am a devout believer that the space elevator is an inevitability, Sean was of the opinion that the technological hurdles are far to great, specifically the problem of where the mass to build the elevator would come from, and whether or not it would need to be built down from a geostationary orbit, or up from the ground. This being one of my favorite subjects, I promised to send him unequivocal internet research that shows just how viable a space elevator is.

For those unfamiliar with the concept, a space elevator is a structure designed to lift payloads from the Earth’s (or other planet’s) surface to space without the use of rockets. While the concept of a tower reaching into space was first proposed by Konstantin Tsilokovsky in 1895, most modern designs center around a super-strength cable or tether which reaches from the Earth’s surface to a counterweight placed in a geostationary orbit.

Imagine a rock tied to the end of a string and swinging it around your head, and you get the idea. By removing the need for heavy rockets and propellants, a space elevator could reduce the cost of lifting a payload into space from approximately $11,000/kg to around $200/kg.

Many were first introduced to the idea of Space elevators by Arthur C. Clarke’s 1980 novel Fountains of Paradise. In 1992, the space elevator played a crucial role in Kim Stanley Robinson’s very popular Mars trilogy, in which space elevators are built on both Earth and Mars. According to Ben Shelef, co-founder of the Spaceward Foundation,

Feasibility
One man who has been working on making the space elevator a reality is Dr. Bradley C. Edwards, a space researcher who literally wrote the book about the space elevator. Working under a NASA Institute For Advanced Concepts (NIAC) grant to develop the space elevator, Edwards published a report which, along with his book, introduced an initial design for the elevator. According to the study:

The main reason that constructing a space elevator on Earth is not currently possible is due to the fact that no material exists in quantity that is strong enough to build a cable that can withstand the enormous forces. However, it has been proposed that a cable constructed out of carbon nanotubes would be strong enough. Carbon nanotubes have been created in the laboratory and are only now being produced in industrial quantities. Demand for carbon nanotubes is expected to increase 178% from 2004-2011.

Now that sufficient quantities of carbon nanotubes are becoming available, the next step is to produce a composite material from them which is long enough to work work with. Carbon nanotubes, by themselves, are too short to be woven into a cable. Therefore, they will need to be formed into a composite material similar to carbon fiber, but much stronger. This goal appears to be well within the reach of our current scientific capabilities, and, once achieved, the door will be wide open to complete the space elevator.

This scientific article outlines, in detail, the feasibility requirements for building the space elevator. The conclusion: a space elevator is very difficult to accomplish, but feasible.

How would it be built?
The proposed design for the space elevator would consist of a very thin ribbon of carbon nanotube composite material, 62,000 miles long, 8 inches wide and as thin as paper.  According to Edwards’ research, construction of the ribbon is the most critical piece, and, while it would be a major engineering achievement, is not beyond current technologies. The ribbon would be launched into orbit via four expendable rockets, and then attached to the orbital platform.

Although I could not find many specifics on construction, most literature suggests that it would be lowered through the atmosphere from the space station to the Earth. According to the LiftPort Group:

This method is analogous to how suspension bridges are constructed. The ribbon would be attached on the Earth to a custom-built ocean platform, located near the equator.

Once built, robotic “climbers” would ascend the cable and would be powered via a laser, which would send a highly focused beam of light to solar panels located on the climber (The laser is to be focused in a such a way as to be harmless to birds or aircraft). Being freed of burden of carrying their own fuel is what makes the whole thing work: climbers are low-mass and high-efficiency. They are expected to carry 13 tons each trip, and each space elevator will carry around 1,000 tons of material to space each year.

Why do we need one?
The space elevator promises cheap, easy access to space. This can be utilized in any number of ways, such as the following:

• Launching satellites
• Removing space debris
• Building orbital solar power platforms
• Colonizing the moon and mars
• Mining asteroids
• Space tourism
• Space defense

Of course, I have to point out the sustainability and environmental benefits from all of this. My personal favorites are orbital solar power stations and removing space debris. But there are a few more. How about reducing emissions from rocket launches? While not a huge factor now, reducing rocket emissions will becomes important as more and more private companies, such as Richard Branson’s Virgin Galactic and SpaceX, enter the market for space. A space elevator would render rocket-based technologies economically uncompetitive.

Perhaps the biggest benefit, and the most long-term, would be making space available to the average person. Once the price of access to space comes down to a certain range, people will begin to think about the possibility of colonizing places such as Earth-orbiting space stations or Mars. Since the biggest factor contributing to biosphere degradation is population, giving human beings somewhere else to go can create a sort of “relief valve” for the planet. Not to mention the fact that, as Stephen Hawking has suggested, it wouldn’t hurt to have a second human-inhabited planet, just in case some unknown catastrophe does come to pass on the first one.

The bottom line
It’s interesting to note that this space elevator proposal is a real design that can be implemented with technology expected to be available within a few short years, and for only $10 billion dollars! There are real companies, such as the LiftPort Group, working right now to make it happen. As outlandish as it may sound, a space elevator is an elegant, efficient, reliable and safe choice for lifting cargo into space. My feeling is that NASA and other space agencies should cease pursuing 1950s-era rocket-based solutions in favor of a space elevator. As with many ideas that started off in a science fiction story, this one is quickly becoming science fact.

Sources:
Wikipedia article: http://en.wikipedia.org/wiki/Space_Elevator
Interview with Dr. Bradley Edwards, http://keithcu.com/wordpress/?p=17
Elevator Man: Bradley Edwards Reaches for the Heights, http://www.space.com/businesstechnology/technology/edwards_boldly_050218.html
The Space Elevator – From Concept to Reality, http://spaceelevator.com/
List of Space Elevator Blogs, http://spaceelevator.com/News/Blogs
LiftPort Group, http://www.liftport.com/wiki/id,space_elevator/
Carbon Nanotube Producing Companies, http://nextbigfuture.com/2008/06/carbon-nanotube-production.html
Nanotube Yellow Pages, http://www.nanoten.com/ntyp.html
The Space Elevator Feasibility Condition, http://www.spaceward.org/elevator-feasibility
KC Space Pirates reach another milestone, http://www.spaceelevatorblog.com/?p=1095
How Space Elevators Will Work, http://science.howstuffworks.com/space-elevator.htm/printable
Elevator:2010 – The Space Elevator Challenge, http://www.spaceward.org/elevator2010

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