ConeXpress is an affordable multi-mission platform that will be launched as
auxiliary payload on the Ariane 5 launcher and as such it exploits the
excess launch capacity of Ariane 5 for easy access to space. The satellite
can be used for different missions depending on the payload placed in it.
The primary objective of ConeXpress is to perform in-orbit servicing. Two
years ago the company Orbital Recovery Ltd started to pursue the market of
in-orbit servicing and has now teamed with Dutch Space to develop
ConeXpress as an Orbital Recovery System. ConeXpress Orbital Recovery
System will prolong the operational life of telecommunication satellites by
supplying guidance, navigation and propulsion for station keeping and
attitude control for an additional 8-10 years.
This Master's Thesis is concerned with the docking phase of the ConeXpress
project. The model for the baseline docking phase is currently being
developed at Dutch Space and the main mechanical element of the docking
system is the Capture Tool, constructed by DLR in Germany. The Capture Tool
is inserted into the apogee kick engine nozzle of a client satellite where
it expands and locks in the throat of the engine nozzle. This Master's
Thesis will deal with a possible alternative concept to the docking phase.
This approach will reduce the mass of the satellite by using only sensors
and control and not any mechanical structures that would complicate the
docking. Using the alternative concept for docking the Capture Tool could
be abandoned and also the high position and orientation control
requirements associated with it.
The work started with an investigation of possible alternative docking
concepts and after a trade-off the most suitable concept, a 3D Laser Camera
System from the Canadian company Neptec, was chosen for further
investigation. In order to test the performance a model of the camera
system needed to be implemented in the DSF, the Design Simulation Facility
(based on MATLAB/Simulink): the simulation environment used in the
ConeXpress project. To get acquainted with the program, simulations were
first made on the original docking concept and also on the rendezvous
phase. After this, simulations for the docking phase using the Neptec 3D
Laser Camera System were started. A simplified version of the System, based
on the docking camera with range, field of view and resolution adapted for
the Neptec system was implemented in the simulator. The results from this
simple model clearly showed first of all that the control system of the
satellite in the simulator needed to...
