Ricerc@Sapienza

This work presents a unified guidance and control architecture, termed VTD-NOG & PD-RM, and describes its application to low-thrust orbit transfer from a low Earth orbit to a geostationary orbit. The variable time-domain neighboring optimal guidance (VTD-NOG) is a feedback guidance technique based upon minimizing the second differential of the objective function along the perturbed trajectory, and was proven to avoid the numerical difficulties encountered with alternative neighboring optimal algorithms.

Lunar orbit dynamics and transfers at low altitudes are subject to considerable perturbations related to the gravitational harmonics associated with the irregular lunar mass distribution. This research proposes the original combination of two techniques applied to low-thrust lunar orbit transfers, i.e. (i) the variable-time-domain neighboring optimal guidance (VTD-NOG), and (ii) a proportional-derivative attitude control algorithm based on rotation matrices (PD-RM).

Accurate orbit injection represents a crucial issue in several mission scenarios, e.g. for spacecraft orbiting the Earth or for payload release from the upper stage of an ascent vehicle. This work considers a new guidance and control architecture based on the combined use of (i) the variable-time-domain neighboring optimal guidance technique (VTD-NOG), and (ii) the constrained proportional-derivative (CPD) algorithm for attitude control.

Future human or robotic missions to the Moon will require efficient ascent path and accurate orbit injection maneuvers, because the dynamical conditions at injection affect the subsequent phases of spaceflight. This research is focused on the original combination of two techniques applied to lunar ascent modules, i.e. (i) the recently-introduced variable-time-domain neighboring optimal guidance (VTD-NOG), and (ii) a constrained proportional-derivative (CPD) attitude control algorithm.

Lunar orbit dynamics and transfers at low altitudes are subject to considerable perturbations related to the gravitational harmonics associated with the irregular lunar mass distribution. This research proposes the combination of two techniques applied to low-thrust lunar orbit transfers, i.e. (i) the variable-time-domain neighboring optimal guidance (VTD-NOG), and (ii) a proportional-derivative attitude control algorithm based on rotation matrices (PD-RM).

Recently, low-thrust propulsion is gaining strong interest from the research community and has already found application in some mission scenarios. This paper proposes an integrated guidance and control methodology, termed variable-time-domain neighboring optimal guidance and proportional derivative-rotation matrix (VTD-NOG and PD-RM), and applies it to orbit transfers from a low Earth orbit (LEO) to a geostationary orbit (GEO), using low thrust.