Trajectory and control systems design for a hovering mesopause probe

Owing to the difficulty in reaching and maintaining the altitude of middle atmosphere layers such as the mesopause, performing in-situ experiments is typically limited in scope. This paper presents a novel approach to overcome both the altitude limitations of balloons and conventional aircraft as well as the limitations of ballistic sounding rocket flight profiles by employing a hovering probe. A throttleable rocket engine burning a storable monopropellant allows the probe to follow a constant-altitude trajectory and to perform science experiments and measurements during its burn phase. In this paper, the different development aspects required to successfully and safely perform such a mission are examined, focusing on trajectory optimization and trajectory and attitude control system aspects, while also presenting mission design and launch vehicle design. Parameter variation simulations are employed to demonstrate robustness of mission design and control algorithms against varying mission and vehicle parameters as well as perturbations. Given vehicle and engine parameters derived from preliminary designs and tests, flight performance simulations yield measurement distances on the order of 20 to 30 km while maintaining a target altitude between 80 and 90 km.