REQUEST is a recursive QUEST algorithm for least-squares fitting of the attitude quaternion of a spacecraft to vector measurements. REQUEST relies on the ability to perfectly propagate the so called K-matrix and is therefore suboptimal when filtering propagation noises. The algorithm presented here provides an optimized REQUEST routine, which optimally filters measurement as well as propagation noises. The solution approach is based on state space modeling of the K-matrix system and uses Kalman filtering techniques in order to estimate the optimal K-matrix. Then, the attitude quaternion is extracted from the estimated K-matrix. A simulation study is used to demonstrate the performance of the algorithm.