Lunar laser ranging by optical transponder collocated with VLBI radio sources on the moon

摘要

The lunar laser ranging (LLR) has been dependent on the retro-reflectors placed on the Moon since the past three decades before. In spite of the technical improvement, regular observations are performed by a limited number of stations due to the weak echo. To allow more opportunities for observations, it is most effective to place modern device on the Moon. Since a Japanese second lunar probe is planned to be launched in 2006, the ideas are collected for scientific purposes. It is described here that an optical transponder on the Moon would enhance the possibility of LLR observations to a large degree. It is also proposed to have three radio sources on the Moon to determine the angular component perpendicular to the Earth-Moon vector and librations. One of the most important scientific targets for the proposed mission is a relativistic experiment which was not attained by a conventional LLR.