Abstract The purpose of this document is to describe the design and simulation of an attitude determination system (ADS) for the CubeSat Colombia I picosatellite, based on an extended Kalman filter EKF [1,2]. In this development the propagation of the State of the system has been implemented through a Runge-Kutta procedure instead of traditional State Transition matrix method, improving predictions from the EKF filter without making direct measurements of angular velocity, it was obtained a reduced prediction time by incorporating a deterministic algorithm (the TRIAD algorithm) within the EKF. The results validated through simulation are those shown in this article. ---------- Keywords: Attitude determination system, extended Kalman filter, non deterministic and deterministic algorithm, picosatellite Colombia I Resumen El proposito de este documento es describir el diseno y simulacion de un Sistema de Determinacion de Actitud (ADS) para el picosatelite Cubesat Colombia I, basado en el Filtro Extendido de Kalman (EKF) [1, 2] . En este desarrollo la propagacion del estado del sistema ha sido implementada a traves de un procedimiento Runge-Kutta a cambio del metodo tradicional por matriz de transicion de estado, mejorando las predicciones del filtro EKF, sin hacer mediciones directas de velocidad angular . Se obtuvo una reduccion del tiempo de prediccion incorporando un algoritmo deterministico (El