Seminar

Dynamical systems have proven to be a useful tool for the design of

space missions. For instance, the use of invariant manifolds is now

common to design transfer strategies. Solar Sailing is a proposed form

of spacecraft propulsion, where large membrane mirrors take advantage

of the solar radiation pressure to push the spacecraft.  Although the

acceleration produced by the radiation pressure is much smaller than

the one achieved by a traditional propulsion system it is continuous

and unlimited. This makes some long term missions more accessible, and

opens a wide new range of possible applications that cannot be

achieved by a traditional spacecraft.



In this presentation we will focus on the dynamics of a Solar sail in

a couple of situations. We will introduce this problem focusing on a

Solar sail in the Earth-Sun system. In this case, the model used will

be the Restricted Three Body Problem (RTBP) plus Solar radiation

pressure. The effect of the solar radiation pressure on the RTBP

produces a 2D family of ``artificial'' equilibria, that can be

parametrised by the orientation of the sail. We note that, due to the

solar radiation pressure, the system is Hamiltonian only for two

cases: when the sail is perpendicular to the Sun - Sail line; and when

the sail is aligned with the Sun - sail line (i.e., no sail effect).



The second example is the dynamics of a Solar sail close to an

asteroid. Note that, in this case, the effect of the sail becomes very

relevant due to the low mass of the asteroid. We will use, as a model,

a Hill problem plus the effect of the Solar radiation pressure, and we

will describe some aspects of the natural dynamics of the sail.