THE SOLAR SAIL LUNAR RELAY STATION: AN APPLICATION OF SOLAR SAILS IN THE EARTH-MOON SYSTEM
- Paper number
IAC-08.C1.3.14
- Author
Mr. Geoff Wawrzyniak, Purdue University, United States
- Coauthor
Prof. Kathleen Howell, Purdue University, United States
- Year
2008
- Abstract
NASA's Vision for Space Exploration calls for an "extended human expedition to the Moon," likely to involve a facility located at the lunar south pole (NASA 2004). Mission planners currently expect that such an expedition will require at least two lunar-relay elements in elliptical, inclined orbits to provide constant two-way communication with the facility at the lunar south pole and the ground-based Earth elements. This paper proposes an alternative: using the additional acceleration from a solar sail to maintain a spacecraft in an orbit hovering above the lunar south pole. A three-dimensional artificial equilibrium surface can be created in a circular restricted three-body (CR3B) system using a solar sail (McInnes 1994). The sail-face normal is aligned in a direction opposite to that of the gravity gradient associated with the primaries. The size of the surface depends on physical sail properties and extends beyond the poles of the primaries for a sufficiently sized sail. In the Sun-Earth system, this equilibrium surface is fixed. In the Earth-Moon system, however, the Sun's rays are constantly moving with respect to the Earth-Moon gravitational field, generating a surface of instantaneous equilibrium locations, which are time variant. For a spacecraft to maintain an orbit near an equilibrium point in the Earth-Moon system, the orbit must move with a point on the constantly shifting equilibrium surface. This surface extends beyond the lunar poles for a sufficiently sized sail, providing equilibrium points in view of the lunar facility at all times. The design of orbits that follow this equilibrium surface in the Earth-Moon system are included in this paper. A discussion of this surface is followed by a strategy for selection of advantageous points on the equilibrium surface. These points are then the reference for an orbit-maintenance or targeting scheme. Farres and Jorba (2007) have proposed using tools from dynamical systems theory to "surf" along points on a Sun-Earth equilibrium surface. Similar methods along with a Floquet-control approach are used in this analysis to target the desired orbit above the lunar south pole. A spacecraft moving along such a trajectory potentially remains in full view of the lunar facility and ground-based Earth elements at all times, providing uninterrupted two-way communications, navigation data, and telemetry. Study of this dynamical system could also lead to new non-Keplerian orbits in the Earth-moon system, expanding possibilities for exploration. Farres and Jorba. 58th IAC, 2007 McInnes, et al. Journal of GCD, 1994. Vision for Space Exploration, 2004.
- Abstract document
- Manuscript document
IAC-08.C1.3.14.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.