Single-thruster attitude control algorithms for prolate spin-stabilised spacecraft

• Main Author: Raus, Robin
• Published: University of Surrey 2013
• Subjects: 629.41
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590662

In the field of attitude dynamics and control, passive spacecraft attitude control by spin-stabilisation can already be considered a venerable technique, almost as old as spaceflight itself thanks to its simplicity. Even today it is still used in a variety of missions, ranging from stabilisation during an orbit boost, e.g. the deployment of the first two Galileo IOV spacecraft, to deep-space astronomy, e.g. the Planck space telescope. Mission concepts have been proposed for spin-stabilised penetrator-like spacecraft targeting non-atmospheric celestial bodies such as the Moon, in the Japanese Lunar-A and the British MoonLITE mission proposals, or Jupiter's Galilean moon Europa in the joint NASA-ESA Europa-Jupiter System Mission (EJSM) proposal, which has recently been extensively remodelled to the mainly European Jupiter Icy Moon Explorer (JUICE). However, the same gyroscopic stability that resists unwanted disturbance torques also has an impact on the commanded manoeuvres. Several techniques have been developed to take into account and whenever possible benefit from the gyroscopic phenomena exhibited by a spinning spacecraft. This thesis will give an overview of the PhD project on single-thruster attitude control of a prolate axisymmetric spacecraft, spin-stabilised around its minimum moment of inertia axis. Having only one attitude thruster on a spinning spacecraft could be preferred for spacecraft simplicity (less mass, less power consumption etc.), or it could be imposed in case of e.g. contingency operations. First of all, the current state-of-the-art slew algorithms Halfcone, Multi-cone, Rhumb Line and the newer Astrium algorithm Sector-Arc Slew have been investigated and qualified. Next, two novel slew algorithms have been identified and developed. One of these is the Extended Halfcone, based on previous sse work. As the name implies, its intention is to extend the usual Half-cone slew algorithm with a mild form of error correction. Another novel algorithm, the Dual-cone slew was designed to overcome the Half-cone limitations regarding attainable slew angles. It is capable of reaching almost any slew angle using two Half-conesj its energy and time consumption performance is comparable to a Multi-cone slew. The conclusion of this section is that there is not a single 'best' slew manoeuvre for all situations.