Space Elevator: Even a space elevator from L1 (Lagrange point 1) to the moon would be a great engineering feat.
So what is a Lagrange Point:
"The Lagrangian points ( /ləˈɡrɑːndʒiən/; also Lagrange points, L-points, or libration points) are the five positions in an orbital configuration where a small object affected only by gravity can theoretically be part of a constant-shape pattern with two larger objects (such as a satellite with respect to the Earth and Moon). The Lagrange points mark positions where the combined gravitational pull of the two large masses provides precisely the centripetal force required to orbit with them." - Wikipedia
Fly me to the Moon - Seattle aerospace company LiftPort is aiming to build a space elevator between Earth’s Moon’s surface and the Earth-Moon L1 Lagrange point by 2020. While the company is pursuing this as a precursor to a space elevator on Earth itself (which is much more difficult), even the Moon-L1 elevator would have tremendous potential to spur human space exploration. How are they going to pay for it? By asking space enthusiast around the globe for their support.
LiftPort’s goal in its Kickstarter funding campaign is a modest US$8,000, which it has already surpassed. This may seem like chicken feed for such an ambitious program, but Laine intended it as a way of sparking public interest. The ultimate goal is to raise $100,000 to $3 million with the first round of funding to be used to continue a preliminary study of the system.
If all goes well, Laine believes construction of the lunar elevator could begin by 2020. The LiftPort lunar elevator would be deployed from lunar orbit with a spacecraft lowering a lander on the ribbon. On contact with the surface, the lander will anchor itself. After that, landing on the Moon will be as simple as docking with the craft in lunar orbit, transferring to the climber car and reading a book on the way down.
The NASA Strong Tether Challenge is held yearly, to see if any teams can build a material strong enough to build a 100,000 kilometer high Space Elevator. With two entrants this year, neither was able to reach the required standard for the prize.
The Strong Tether Challenge is driving material science technologies to create long, very strong cables (known as tethers) with the exceptionally high strength-to-weight ratio. Such tethers will enable advances in aerospace capabilities including reduction in rocket mass, habitable space structures, tether-based propulsion systems, solar sails, and even space elevators. Dramatically stronger and lighter materials are also revolutionizing the engineering of down-to-earth structures such as aircraft bodies, sporting good equipment, and even structures of bridges and buildings.
NASA’s Power Beaming Challenge has also been running with a similar goal, to find a system capable of beaming power from a ground station to a robot which would climb the tether. That competition was won in 2009.
The next big challenge will be in 2012, when a “power beaming to lunar rover” competition will be held.