Various planetary terrains or asteroids, which are hard to traverse with wheeled platforms, are expected to be explored. Bekker’s model cannot be applied to estimate the motions of rovers without wheels, such as the hopping rover (hopper). In this paper, the resistive force theory (RFT) approach is introduced. This approach is not based on Bekker’s model, and is expected to apply to any platform. However, this RFT approach only applies to static or quasi-static motion, such as in the case of slow motions. To apply the RFT approach to dynamic motions, such as hopping, the effect of velocity as a dynamic variable is also studied. Through the hopping experiments, the effectiveness of RFT with the velocity-term approach is investigated and compared to the RFT approach.

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