After about twenty years studying of Pioneer-effect the theory that the origin of this anomaly is a recoil force associated with an anisotropic emission of thermal radiation off the spacecrafts received significant support. Although dependence of additional radial acceleration on radial velocity towards to Sun a=-Q(v_r)^2 with Q= 4.13*10^(-20) cm conforms to the basic properties of the Pioneer-effect. Estimation of its action on radial perturbations of Neptunian satellites Proteus and Triton in a first approximation gives close to observed values.