The drifting trajectory analysis of the reentry recovery module RATS with inflatable deployable aeroshell is validated with the drifting trajectory based on the flight experiment data. The RTOFS sea surface current forecast data and the GFS ocean wind forecast data, released from NCEP, are employed in the drifting trajectory analysis. It is shown that the RATS can float for a long time, although the inflatable ring is filled with CO₂ gas, which has large gas permeability of the gas-tight layer. The leeway coefficient for drifting trajectory analysis is estimated to be 0.038 based on the floating design of the RATS. The drifting trajectory analysis was performed using the RATS landing point as the initial position. It was confirmed that the predicted drift direction agrees with the RATS drifting trajectory. However, the difference between the predicted result and the drifting trajectory increases with time in the ocean wind direction. The difference is approximately 0.8 km after 100 minutes from splashdown.