Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Solar sailing has been long in the coming, a notion almost a century old and only recently
demonstrated to work. The idea of using ambient photons for space propulsion is an appealing
one not only for the elegance of not having to carry heavy fuel, but also for the special physics
of a continuously accelerating spacecraft.
One of the proposed architectures for a light, modular solar sail is the Space Tow, consisting
of hundreds of
mm thin sheets suspended in several km of carbon filament, at the same time
stowable in mere meter-scale height.
This thesis investigates the deployment mechanics of the Space Tow for two passive deployment
strategies, “drag along” and “leave behind” deployment. Simulations were made using a
simple 3D model in ABAQUS/Explicit and compared to a 1D mechanical analysis.
Many of the problems with these deployment schemes were of acceleration-rate changes
and the damping thereof. The last part of the thesis touches upon the involved energies and
how these could be dissipated by dry friction, as well as how this would be described in an
acceleration-rate proportional damping constant for use in future models.
The thesis concludes that the “drag along” scheme is sensitive to perturbations and that the
“leave behind” scheme needs careful consideration of its parameters or risk that the undeployed
stack accelerates to pass the deployed structure.
The thesis is composed of two parts, section I is a background presenting the subject and
available literature. After that follows an article which at the time of writing is to be presented
at the 3rd International Symposium on Solar Sailing, 2013.