Several weeks ago Thoth Technology, Inc., a Canadian company located in Pembroke, Ontario, received U.S. Patent No. 9,085,897, which is simply titled Space Elevator.
The Background cites to famous author Arthur C. Clarke, who hypothesized that a space elevator could be constructed suing a cable and counter-balance mass system in his 1978 novel The Foundations of Paradise. The patent explains that the Clarke vision of a space elevator could be constructed by launching a cable into space. Unfortunately, sufficiently strong materials to realistically enable construction of the cable still do not exist. Therefore, there still remains a need for a space elevator that could provide access to space, or near space.
According to the Summary of the Invention, the disclosed space elevator is a self supporting tower for the delivery of payloads to a platform above the surface of the Earth. The patent explains that the space elevator tower will provide access to lower altitude regions, but can also be scaled to access altitudes above15 km, which is a bit higher than the typical altitude ceiling for a Boeing 777 commercial aircraft. The patent also goes on to say that the space elevator tower could be further scaled to provide direct access to altitudes above 200 km.
The inventor explains that the purpose is to allow payloads to be taken up to the elevator where they can be launched into space. By raising the payload sufficiently above the surface of the Earth there would be significant advantages because it would be easier to escape the Earth’s gravitational pull, thus reducing the amount of fuel that would be required to place the payload into space, or into orbit around the Earth.
The patent application explains:
Although ascending to an altitude significantly below 35,000 km will not place a payload in Earth orbit, a platform or pod supported by the space elevator tower has significant advantages over a surface-based launch platform. While surface-based rockets must be designed to overcome atmospheric air resistance, launch from a high-altitude platform has no such requirement, and, consequently, existing space equipment such as an orbital transfer stage or conventional upper stage can be used to insert payloads directly into Earth orbit. Ideally, payloads should be raised to the highest feasible altitude before launching in order to maximize the energy advantages; however, the energy advantages for space flight are readily leveraged above 5 km.
A platform or pod supported by the space elevator tower also has significant advantages over orbiting satellite platforms. Geographically fixed, but providing access to regions of space closer to the surface than geostationary orbit, elevator platforms provide the ideal means to communicate over a wide area and to conduct remote sensing and tourism activities. As a tourist destination, the elevatorplatforms provide stations located at fixed attitudes from the surface for observation. The elevator platforms provide the means to safely access a region of space with a view extending hundreds of kilometers.
The space elevator tower may also provide a near-surface observation platform with oversight over a fixed geographical area. Such platforms can be used for observation, remote sensing and communications. Small systems may be mobile and delivered to sites for temporary applications for example to provide temporary communications towers typically between 25 m and 150 m. Used with an elevator component equipment may be accessed and maintained during operation. Used without an elevator component, equipment may be installed only during the construction of the apparatus.
But how will the space elevator be realized mechanically? According to the patent the space elevator will be made up of a segmented elevator core structure. This core structure will be pneumatically pressurized and at least partially formed from flexible sheet material that will be supported by internal gas pressure. The space elevator tower will have a main pod at the top, which will provide a launch device for launching objects from the main pod, a platform for at least one person or for communications, and/or remote sensing equipment. The space elevator tower will maintain a desired pressure level through gas compressor machinery.
The Detailed Description goes on to explain that the core segment will be composed of multiple adjacent hollow cylindrical pressure cells each having the same length as the core segment itself. The pressure cells will be filled with a pressurized gas, such as for example hydrogen (see claim 20) or helium (see claim 21). The walls of the pressure cells will be made of a material with very high mass-to-tensile strength properties, such as boron or a Kevlar polyethylene composite. The material of the walls is otherwise generally sheet-form and flexible, which means that by itself it will provide no significant strength in compression.