Abstract
The internal structure of the Moon is one of the most important clues to the evolution and origin of the Moon. A lunar gravimetry by differential VLBI observation, named dVLBI, is proposed for the SELENE-2 to improve the internal structure model, especially for the core. As a recent review of the dVLBI mission, two topics are shown. First, new operation modes are introduced for the purpose of saving the transmitter’s electric power. The power consumption is reduced from 9.6 W to 2.1 W in the case of the dual frequency and intermittent transmission modes. Error estimation of the lunar potential Love number k2 shows that the desired accuracy can be achieved in the case of the intermittent transmission mode. Second, the S-band survival antenna that will be installed on the lander is designed. A computational simulation using an analytic model shows that the required performances, which are gain of -5 dBi, beamwidth of 60 degrees, and bandwidth of 140 MHz, are achieved at a temperature within a range of -200 to +120 degrees.
