Optimal steering law of refractive sail

Solar sail heliocentric transfers with a Q-law

“…where p a(1 − e 2 ) is the osculating orbit semilatus rectum, h √ µ p is the angular momentum vector magnitude, and {a P R , a P T } are given by Eqs. ( 9)- (10). Starting from Eqs.…”

“…Although the existence of solar radiation pressure has been known for a long time, the recent successes of solar sail-based missions, such as IKAROS [5,6], LightSail-1 [7] and LightSail-2 [8], have given a renewed impulse to the technological development of the solar sail concept. For example, refractive and diffractive sails have been recently proposed, which are capable of generating an in-plane transverse thrust even in a Sun-facing configuration [9,10]. The interest of the scientific community on solar sailing has led to the design of several solar sail-based missions, including NASA's NEA Scout [11], Solar Cruiser [12], and JAXA's OKEANOS [13,14], which require a deep space transfer phase to reach the target position or the working orbit.…”

Solar Sail Simplified Optimal Control Law for Reaching High Heliocentric Distances

“…Other more accurate (and more complex) thrust models [18] exist, which take into account the optical properties of the reflective film [19], the degradation of the sail surface [20,21,22,23], the sail billowing [2,24], the presence of wrinkles [25,26], diffractive effects [27], and the uncertainties associated with the reflective film characterization [28,29,30]. However, the ideal force model has been chosen here to allow the results obtained in this analysis to be compared with a large amount of literature results [5,12,13].…”

Feedback control law of solar sail with variable surface reflectivity at Sun-Earth collinear equilibrium points

“…4, which shows that control torques lying on the sail nominal plane are obtainable with RCDs, whereas a control torque normal to the sail nominal plane (i.e., along the direction of n) must be generated with a different strategy. To that end, a promising option is the utilization of PDLCs [24,25], which are capable of exploiting the incident photons to generate a tangential force. To describe the solar sail attitude, which determines the direction of a, it is useful to introduce a body reference frame T b (S; n, p, q) with origin at the spacecraft center-of-mass, whose unit vectors { p, q} lie on the sail nominal plane along the principal axes of inertia; see Fig.…”

“…Moreover, RCDs can also generate control torques belonging to the sail plane, which are useful to properly orient the propulsive acceleration vector, as tested (and validated) by the pioneering IKAROS mission [23]. The flexibility of RCDs could be further increased by means of polymer dispersed liquid crystals (PDLCs) [24,25], which may refract the incoming sunlight to generate a small tangential force, and so a control torque perpendicular to the sail nominal plane. A further strategy for varying the sail thrust magnitude and direction has been recently discussed by Luo et al [26], who proposed the concept of a solar sail composed of controllable blade elements.…”