The SELENE2 project is planned a few years after SELENE, a Japanese lunar exploration project to be launched in 2003 by ISAS/NASDA. SELENE includes several selenodetic missions proposed by us, including the first direct gravimetry of the lunar farside. In SELENE2, we are proposing a new selenodetic mission, In-situ Lunar Orientation Measurement (ILOM) to observe lunar rotational variations (physical librations) directly from the Moon. The main component is a compact optical telescope (Cassegrain type, diameter: 20cm, focal distance: 4m) put within the eternal shaddow regions around the lunar poles. It is fixed to a lunar celestial pole, and equipped with a CCD camera with 4000x4000 pixels to determine the instantaneous positions of several tens of stars in the observing range accurate to 0.1 arcsecond. Year-long trajectories of such stars provide information on forced and free librations, more directly than Lunar Laser Ranging (LLR) observations do, leading to the detection of major components of the forced librations as well as the free libration with the 75 years period.