CanX-4 and CanX-5 (Canadian Advanced
Nanospace eXperiments) are a pair of identical nanosatellites, planned for launch
in 2008. Their primary mission is the demonstration of on-orbit formation flying. In this
context, formation flying is defined as two or more satellites controlling their position
and orientation with respect to one another to achieve a predefined configuration
necessary for coordinated operations.
CanX-4 and CanX-5 will use the technology proven aboard CanX-2
to achieve and maintain several controlled formations in orbit. Formation will be
controlled with the second generation Nanosatellite Propulsion System (NANOPS) being
developed at UTIAS/SFL. During the mission, the team will evaluate the propellant usage in
autonomous formation control strategies.
To enable autonomous control, CanX-4/-5 will employ innovative carrier-phase
differential GPS techniques to obtain relative position measurements accurate to less than
10 cm. This research is done in partnership with Prof. Elizabeth Cannon and Prof. Susan
Skone at the University of Calgary. CanX-4 and CanX-5 will coordinate their operations
using an SFL-developed inter-satellite communication link. Control strategies for
formation maintenance will be provided by Prof. Christopher Damaren at UTIAS.
With thrusters located only on one side of each spacecraft, it is necessary to slew the satellites to a new attitude vector for each successive thrust during formation flying.