# Would the Poynting–Robertson effect ever be faster than a solar sail from a 1 AU orbit to the Sun?

In this answer to Do you need 0 km/s velocity to crash into the sun? I mention solar sails for retrograde thrust and the Poynting–Robertson as two ways an object could ever-so-slowly spiral into the Sun.

Using known materials with modest extrapolations (like they do for solar sails) and ignoring deterioration due to solar wind, radiation damage and meteorites, is there some mass regime where a configuration optimized for Poynting–Robertson effect would be faster than a configuration optimized for a vanilla solar sail to get from a 1 AU orbit to the Sun?

For example, if two teams were assigned the task of designing a passive Sun-spiraling craft and given the same mass constraint, would the SolarSailors team always win no matter what mass was choses, or are there some masses where the PoyntingRobertsons could win?

• – uhoh Jun 6 at 13:10

On the other hand, Poynting–Robertson effect is equivalent to the same but at incidence angle of $$arctan({c \over 29.7 km/s})$$, that is about 89.994 degrees. Almost but not quite the completely useless 90 degrees where none of the light would contribute retrograde thrust and in fact none would hit the sail surface.