Simultaneous Wireless Data and Power Transfer Testing onboard the Nanokhod Microrover Tether Mechanism for Lunar Surface Exploration

This paper presents ongoing research activities for simultaneous power and data transmission over a miniaturised single coaxial tether, developed for the Nanokhod Microrover for lunar and planetary surface exploration. The use of a combined link significantly reduces system complexity, mass, and potential failure points. However, the interaction between the inductive fields of power and data transmission introduces substantial electromagnetic interference. A detailed analysis revealed opportunities for further development of the existing solution in order to increase robustness, data rates, and functionality of the power and data transfer. To overcome challenges, full-period demodulation, digital low-pass filtering with a rect filter, and active analog high-pass filtering were implemented. The fullperiod demodulation compensates for asymmetries in the data signal caused by the 60kHz interference, while the digital filter improves robustness against transient disturbances. On the lander side, an active filter suppresses the dominant 120kHz interference after the tether. Practical measurements demonstrate stable, reliable half-duplex communication without bit errors at a data rate of 500kBd during continuous power transfer of 10W over a 100m tether.