Scenario Description of the Construction of a Lunar South Pole Infrared Telescope (LSPIRT).

On the Moon, unique situations exist for observing the infrared parts of the spectrum because of the lack of an atmosphere. In the Polar areas this situation is extremely good because of the Permanently shadowed areas which belong to the coldest places (50K) in our solar system. This means that the surrounding infrared background radiation which disturbs the measurements is very low. The South Pole offers the best location to build such an observatory. From research done a few years ago by several sources with data of the Clementine mission it appears that a unique combination exists at the South Pole. Permanent Shadowed areas located within a few kilometers of a small area that is almost permanently lit by the sun, often referred to as "peak of eternal light" (PEL). By placing a communication relay on one of the Lunar Mountains it is also possible to have direct communications with this PEL which can not be seen directly from Earth. This combination results in the location choice for the placement and construction of the Lunar South Pole Infrared Telescope in Shackleton Crater together with a communication relay station in the form of a lander at Malapert Mountain and another communication relay and energy supply station in the form of a lander at the Peak of Eternal Light. In this paper a description will be given of the design of the telescope and the scenario that was chosen to construct this telescope. The Location and type of mission requires a design that is scenario and environment driven. The Scenario determines way of construction (on earth, in orbit, on moon),timeline and maximum masses, sizes and volume of the payloads to be delivered to the lunar surface. The location on the Moon means that no infrastructure or resources are available without processing except for the lunar regolith itself. The environment determines the choices of materials and details (dust, ground situation) The local terrain determines communication, energy-supply, light, resources, location, foundation and the way of construction. It appears that it is possible to built a telescope with the same capabilities as the Next Generation Space Telescope on the Lunar South Pole except for the sky coverage that will be limited by the location and orientation. The telescope has a diameter of 8 meters and is an altitude-azimuth design. The bearings will be made of superconducting magnets that use fluxpinning to stabilise themselves while at the same time they are very energy-efficient. The foundation will be put together and dug in-situ using robots and telepresence in a virtual reality environment and using local laser rangefinders. If all goes well the telescope is expected to have settlements no larger than 0,03 mm during operation. When the telescope is built, an infrastructure has been created for energy supply and relaying communications. The total mission is achieved by launching 3 ariane 5 rockets in the 2006 configuration that can launch 20,000 kg in GTO.