A vehicle includes a vehicle body, a vehicle power source, and an actuator. The vehicle power source includes a housing and a power generator. The housing is rotationally mounted on the vehicle body and is configured to rotate, relative to the vehicle body, about a first rotational axis. The power generator is rotationally mounted within the housing and is configured to rotate about a second rotational axis and generate power. The first rotational axis and the second rotational axis are orthogonally disposed. The actuator is coupled to the housing and is operable to selectively rotate the housing about the first rotational axis. By gimballing the rotating mass of the power source a gyroscopic torque can be applied to the vehicle improving its maneuverability.

Rockets, rocket motors, methods of controlling a rocket and methods of evaluating a rocket design are disclosed. In some embodiments, a method of controlling a rocket may include measuring a combustion chamber pressure, calculating a logarithm of the measured combustion chamber pressure, and computing the difference between the logarithm of the measured combustion chamber pressure and the logarithm of a reference combustion chamber pressure value to generate an error signal. The method may further include filtering the error signal to generate a compensated signal in the logarithm domain, and exponentiating of the compensated signal in the logarithm domain to provide a compensated signal in the physical domain.

A propulsion system for controlling the orbit of a satellite in earth orbit comprises a thruster suitable for delivering a force along an axis F, and a motor-driven mechanism linked on the one hand to the thruster and on the other hand to a structure of the satellite, said motor-driven mechanism being suitable for displacing the thruster on either side of the plane of the orbit and suitable for orienting the thruster so as to make it possible to control a component perpendicular to the orbit of the force in two opposite directions, to control the inclination of the satellite, and in that said motor-driven mechanism is suitable for displacing the thruster along an axis V parallel to the velocity of the satellite, and suitable for orienting the thruster so as to make it possible to control a component of the force on the axis V, to control orbit.