There is a growing international need for Space Situational Awareness (SSA), defined as
knowledge of objects in Earth orbit and the space environment. Up until recently, the …

The problem of the artificial frozen orbits around the Earth is investigated. To design such
orbits with arbitrary orbital parameters, six control strategies are discussed taking into …

The accuracy of the orbital data products used for space situational awareness is affected by
the evolution of the sensors collecting the data, the knowledge and control of the errors in …

The semi-analytical theory for the motion of a space object replaces the conventional
equations of motion with two formulas 1 equations of motion for the mean equinoctial …

An improved accuracy model for the J2 zonal harmonic second order terms, J2 2, in a
general semi-analytical satellite theory is described. The new model is implemented as an …

There are currently more than 19,000 trackable objects in Earth orbit, 1,300 of which are
active. With so many objects populating the space object catalog and new objects being …

Since the inclination of frozen orbit with non-rotation of the perigee that occurs due to J 2
perturbation must be equal to the critical inclination, this regulation has restricted the …

Space agencies generally use numerical methods to meet their orbit determination needs.
Due to the ever increasing number of space objects, the development of new orbit …

The issue of satellite operations in close proximity to a reference satellite is of interest for
both civilian and military applications. One such operation is fast fly around formation in a …

Analytical gravity models are included in the equinoctial element formulation of the low-
thrust optimal equations of motion and the adjoint equations for the Lagrange multipliers …