  Over the several decades, the space debris at LEO has grown rapidly which had
caused a serious threat to the operating satellite in an orbit. To avoid the
risk of collision and protect the LEO environment, the space robotics ADR
concept has been continuously developed for over a decade to chase, capture,
and deorbit space debris. This paper presents the designed small satellite with
dual robotic manipulators. The small satellite is designed based on CubeSat
standards, which uses commercially available products in the market. In this
paper, an approach is detailed for designing the controlled chase and deorbit
maneuver for a small satellite equipped with an RCS thruster. The maneuvers are
comprised of two phases, a. bringing the chaser satellite to the debris orbit
and accelerating it to close proximity of 1m to the debris object by using the
low thrust RCS thruster, and b. Once captured, controlled deorbiting it to 250
km of altitude. A Hohmann transfer concept is used to move our chaser satellite
from the lower orbit to the debris orbit by two impulsive burns. A number of
the scenarios are simulated, where one or more orbital elements are adjusted.
For more than one orbital elements adjustment, the DAG law and the Q law are
utilized. These laws synthesize the three direction thrusts to the single
thrust force for the controlled maneuver. The $\Delta$V requirement at each
maneuver is determined by using the performance parameters of the RCS thruster
intended for a small satellite. The results show that, for long term simulation
of a chaser satellite maneuver to debris object, an optimum DAG law is most
suitable than the Q law, as it can handle the singularity behavior of the
orbital elements caused due by adjustment of one or more elements more
efficiently.
