Abstract:
The quest for the direct detection and observation of gravitational waves
remains one of the lasting scientific challenges of the 20th century, and one
that will continue on into the 21 st. Concepts and technologies are being
developed that will, early in the new millennium, allow their direct
observation for the first time. This will be the beginning of the gravitational
wave astronomy revolution.
The LISA (Laser Interferometer Space Antenna) mISSIOn is one of the
cornerstones of this revolution. Observing in the low-frequency band, it will
provide information about our universe that cannot be gathered from the
ground. This band contains sources fundamental to our understanding of
how the universe began and operates.
In turn, fundamental to the LISA mission is the concept of drag-free control.
This provides the relatively undisturbed environment for the test-masses
which form the references for the measurement of the gravitational waves.
Without it the effect of gravitational waves would be but a whisper amongst
a cacophony of disturbances.
It is drag-free control for the LISA mission which forms the basis for the
majority of this thesis. The research and development work carried out by
the author has involved the development of a control model of the LISA dragfree
control system to assess its feasibility. The author proposes a different
approach to the problems involved from that suggested by other authors. It
is shown that this approach, unlike those suggested in the mission baseline
studies, fulfills the control requirements for the LISA mission.
Technological risk assessment in general, as well as that associated with the
LISA mission, is also considered.
