Skip stone

Some Chinese researchers took what we all know from skipping stones, and applied it to a spinning aluminium disc.

"Vertical acceleration" turns out to be the factor here; the acceleration which the water provides, by lift. Between 3.05g and 3.8g, the disc bounces; above that, it skims along the surface - they call it "surfing". g = 9.8 ms^-2 here, although we seem all agreed the same rules apply for the Moon's lower g if we get a covered pond over there.

The editors want this for space reëntry to Earth. They're thinking, water landings - but I'd go further. There's already a Boost Glide trajectory for shedding delta-V over a longer period. We on Earth have mostly used that to lower the heat on the hull. Maybe some craft can skip across the outer atmosphere for longer.

I wonder what these results will look like over other liquids, like Titan's lakes. As to Venus: below its atmosphere of nitrogen and carbondioxide is a CO₂ supercritical fluid. Can this be skipped over?