The implementation of missile guidance laws on collision course trajectories with bearings-only measurements may result in bad range observability. This in turn may result in poor engagement performance for those guidance algorithms that exploit range information in their steering law. Maneuvering away from the collision course trajectory improves range observability. To propose a sizing criterion for this maneuver, this work presents a new guidance strategy that exploits the information from the error covariance matrix of the homing loop integrated Kalman filter in the framework of a pursuit-evasion game. The new strategy has been tested in several scenarios against other guidance laws, such as the classical formulation of the pursuit-evasion game and proportional navigation. Numerical simulations on a set of Monte Carlo samples show that the proposed solution is able to improve engagement performance in terms of both miss distance and range observability.

This paper deals with the design, realization and testing of an Earth magnetic field simulator, that allows to validate hardware in the loop algorithms, as well as to test new actuators. The design is driven by typical small satellites functional requirements. The subsystems that compose the simulator are described in detail. The validation of the simulator is performed by assessing its functioning, the uniformity of the recreated magnetic field and the functionality of a magnetorquer.

This paper introduces a filter for tracking a ballistic missile during its boost phase. This filter includes a new switching algorithm and a modified interacting multiple model unscented filter (IMMUF), where the Markov transition matrix is time variable. Position, velocity, and all unknown parameters of a medium-range ballistic missile model are reconstructed. Simulations demonstrate that the new filter is able to consistently estimate a missile's trajectory and all unknown parameters and to outperform the previous forms of the IMMUF.

To simulate the conditions of the space environment at ground, the Laboratory of Application and Innovation in Aerospace Science (LAICA) of the University of Brasília (UnB) is developing a dedicated testbed to reproducing nanosatellite attitude motion. The testbed is composed of an air-bearing table and a Helmholtz cage. The air-bearing table is a spacecraft simulator that can simulate frictionless conditions with three rotational degrees of freedom. Balancing the simulator is essential in order to make the gravitational torque negligible. The testbed is also equipped with a Helmholtz cage to recreate the Earth’s magnetic field conditions that spacecrafts encounter in orbit. This paper presents the design and realization of this low-cost testbed. A simple and efficient automated balancing algorithm based on the least-squares method (LSM) is proposed and validated by experiments. The performance of the proposed simulator is evaluated and compared with previous works.