Kosmodemyanskaya orbits the Sun in the inner main-belt at a distance of 2.1–2.9 AU once every 3 years and 10 months (1,402 days). Its orbit has an eccentricity of 0.16 and an inclination of 5° with respect to the ecliptic.
The first rotational lightcurve was obtained by American astronomer Richard P. Binzel during a photometric survey of small main-belt asteroids in the 1980s. It showed a rotation period of 4.4 hours with a brightness variation of 0.09 magnitude (U=2). In November 2004, another lightcurve of Kosmodemyanskaya was obtained by French amateur astronomer Laurent Bernasconi. Lightcurve analysis gave a period of 10 hours with an amplitude of 0.05 magnitude (U=2-).
Diameter and albedo
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Kosmodemyanskaya measures 4.843 kilometers in diameter and its surface has an exceptionally high albedo of 0.522, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 8.93 kilometers with an absolute magnitude of 12.61.