Power beaming is a fundamental technology component of the Space Elevator. Without it, we have no way to transfer power to the electric climbers as they ascend the tether on their way to geosynchronous orbit. Creating this "cordless extension cord" is useful not only for Space Elevator climbers, but also for other exploration challenges such as powering rovers inside dark lunar craters
How far is 1 km? About 2/3 of a mile - just a tad lower than an airliner is when the captain asks you to turn off you electronic devices. Roughly equal to the minimum distance that will be useful for lunar exploration, and only 1/10,000 of what is needed for a Space Elevator... But even the journey of 10,000 km must start with a single step!
The Power Beaming challenge was designed to promote development of progressively more efficienct and far reaching beam-powered Space Elevator climbers as well as influence public perception of the Space Elevator project by actually demonstrating its operation. The total NASA provided prize purse was $2M, highlighting its commitment to the development of power beaming technologies.
Attempting this challenge requires that the participating teams would excel at laser optics, photovoltaics, electrical and mechanical engineering, and overall system design. The vehicles must be lightweight yet powerful. The laser beams must be well focused while tracking the climbers, and the climbers must be adept at converting them back into electricity and then into mechanical power. If you think this sounds complicated, you're right - out of about 40 teams that tried their hand at the challenge, only 3 made it to the final challenge.
The single most difficult task in building the Space Elevator is achieving the required tether strength-to-weight ratio -- in other words, developing a material that is both strong enough and light enough to support the 60,000 mile long tether.
Compared to the best commercially available tether, we need a material that is almost 25 times better - about as great a leap as from wood to metal. Quite a tall order!
Luckily for us, about 15 years ago a new material was discovered, one that has the potential of fulfilling these seemingly impossible requirements.
The material, Carbon Nanotubes, is only now becoming available from laboratories in its raw form in sufficient quantities.
The task ahead is to weave these raw CNTs into a useful form - a space worthy long tether.
The following chart illustrates quite well how far it is we have to go... We plot the competition results, as well as product spec sheets and published results against a hypothetical 50% yearly improvement curve. Can material strength match this curve? Will progress be steady and linear or will it be characterized by large improvements followed by years of no progress? Time will tell.
In order to encourage CNT laboratories to place greater emphasis on the tensile strength properties of CNTs, we have posted an open dare to industry and academia:
The total prize purse was $2M (divided between four prize levels), provided by NASA's Centennial Challenges program, to be awarded to the teams that can demonstrate the best Space Elevator tether samples.
The challenges are designed to address the "social engineering" of the Space Elevator. Taking our cue from the X-prize, solar car races, and various other competitive ventures, we use engineering competitions as a tool to capture mindshare in academia, space enthusiast community, and the general public. If we can have even 10 universities and 100 engineering students involved with the Space Elevator project each year, we'd have left our mark on the aerospace community.
In the days of airships, the advocates of planes devised a new way to promote their (obviously impractical...) inventions. It was called an "air show", and it had a dual purpose:
First, these pioneers knew that they could explain airplanes all they wanted using equations and diagrams - it was not until they showed them flying that they really got their message across.
Second, they recognized the power of competition - by bringing together airplane enthusiasts in a competitive environment, they were able to accelerate the rate of development beyond what was likely in the isolated confines of their shops.
Our goal is to infect the engineering and science community with our passion for building the Space Elevator, thus making them ambassadors to our cause.
As the fruits of their efforts take to the sky every year, we will have demonstrated the feasibility and sheer simplicity of the Space Elevator concept, and will have brought it closer to reality.
Our prize money is provided by NASA's Centennial Challenges program - a total of $4,000,000 over the next 5 years! To maximize our return and reduce our risk, we distribute the money in slowly increasing increments, as we ratchet up the difficulty level of the challenges.
Climbing The Sky
The dream of a Space Elevator is a monumental one. A vision that will not only further space exploration and knowledge,
but has the potential to shape the existential future of the human race for centuries to come.
For the first time since it was initially conceived, this dream is now within our reach.
With our challenges, the Spaceward Foundation has joined the on-going construction effort, adding energy, resources and new initiatives to the ever-growing number of organizations, companies, websites and enthusiasts focused on the technical, political and economic development of the Space Elevator.