28 August 2012, 15:56

Lunar space elevator idea gets new lease of life

Lunar space elevator idea gets new lease of life

Private enterprise LiftPort Group has announced its ambitions to deliver humans and cargo to the Moon using a space elevator. The idea of a space elevator has first been suggested by Russian scientists. Unlike earlier designs, this project stipulates that a space elevator is linked to the Moon rather than to the Earth. Regardless of the feasibility of the now-extravagant ideas of space transportation, the question remains as to who and what would be sent to the Moon.

News of the space elevator project came at the same time as the sad news of the death of Neil Armstrong, the first man on the Moon. The Saturn V rocket, the brainchild of Wernher von Braun, that delivered Apollo 11 to space, weighted 2,800 tons, while only 45 tons were delivered to the Moon. In comparison, the Soviet N-1 which also aimed to be the launch vehicle for manned lunar expeditions weighed approximately 2,700 tons at the launch pad. These payloads made further lunar expeditions very unprofitable, since investments by far outweighed the gains.

Consequently, the idea to invent cheaper methods of reaching the Moon on a regular basis persisted, and the concept of a space elevator is among the most popular, even though its technical feasibility is still heavily questioned.

Founded by former researcher at NASA’s Institute for Advanced Concepts Michael J. Laine, LiftPort Group has announced that it is going to build a space elevator that would transport people and cargo to the Moon, since it is easier to build than an Earth-based facility.

The main part of the facility would be a ribbon anchored to the lunar surface with the other end located at Lagrange Point 1, namely the point between the Earth and the Moon (approximately 55 thousand kilometers from the latter) where the two gravity fields are in balance, so that the spacecraft can in principle remain forever in the same place. Since the Moon always looks to the Earth with its near side, the other end of the ribbon will stay in the same place relative to the Moon’s surface. A rocket will deliver cargo or humans to the spacecraft in the L1 point, to then be lowered to the Moon by robotic elevator.

The founder of the company is convinced that current materials are strong enough to sustain the elevator, and assess the price of such a journey to be about one tenth of a Space Shuttle launch (according to NASA, it cost about $450 million per mission), He also believes the system to be capable of transporting about 36 people to the Moon per year.

The idea of a space elevator is by no means new, since it was made widely known by Sir Arthur C. Clarke in his 1979 novel “Fountains of Paradise”. However, it was not Clarke that invented it, but the idea was borrowed from Soviet engineer Yuri Artsutanov who, then a graduate student at Leningrad Technological Institute, wrote about such a facility in 1960. Artsutanov had developed the earlier idea of Konstantin Tsiolkovsky, who proposed to build a “space tower” to deliver people and cargo to space.

The advocates of the idea insist that current technologies mean such a structure can be built, although it still is a challenge. The primary goal that LiftPort Group is striving to reach is to secure enough funds for work to begin. A fundraiser was launched on August 24 and will end on September 13, hosted by an online platform. It was reported that four days have already brought more funds than the necessary $8,000 required to make the first ground tests. A more substantial amount of $3 million for detailed construction plan is already looming on the horizon.

LiftPort Group also uses the Internet for the project itself, as the company wants to draw space enthusiasts from all over the world to exchange their ideas on the project. Unfortunately, the company’s website is still far from complete and now looks mostly like a blog. Therefore it is hard to pass judgment on the project.

There are several ideas for transport systems other than launch rockets. One of them suggested by Russian engineer Igor Sidorov of the Space Research Institute of the Russian Academy of Sciences. His system includes three so-called “slings” – revolving rope systems which can be used to hook and release the cargo, sending it into orbit to the Moon.

This system, however complicated, is apparently feasible, and, moreover some experiments with the use of rope systems have been already performed by the US and the USSR. However, due to extreme complexity and other reasons, they did not end up with working models.

There are still doubts as to whether these alternative systems are worth further development. At the same time, launch rockets have already established a good reputation, even though there are limits on the mass of the launcher. Current lunar plans of space powers stipulate that spacecraft will be delivered to the Moon via conventional rockets.

On the other hand, rope systems and space elevators – provided their overall technical feasibility – are meant for regular use rather than sporadic expeditions. Space tourism, however fashionable it might sound, would not provide enough funds to maintain these systems, since it remains too expensive to become ubiquitous. The answer to the question of what is actually needed to deliver to the Moon and back is what should be sought.

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