Distributed Reflectivity Solar Sails for Extended Mission Applications

Borggräfe, Andreas; Heiligers, Jeannette; Ceriotti, Matteo; McInnes, Colin R.

doi:10.1007/978-3-642-34907-2_22

Cited by 7 publications

(7 citation statements)

References 10 publications

(12 reference statements)

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“…However, the area covered by these devices in the case of Ikaros is small, which results in small variations of the total force. There are nonetheless proposals in literature to cover the full solar sail with similar devices, to utilize them for shape changing or for attitude control by selective variation of the reflectivity across the surface (Borggräfe, Heiligers et al 2013). In practice, a combination of both variable surface and variable reflectivity may be required.…”

Section: VIII Solutions For System Implementationmentioning

confidence: 99%

Alternating Orbiter Strategy for Asteroid Exploration

Yárnoz¹,

Cuartielles

McInnes

2015

Journal of Guidance, Control, and Dynamics

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This paper proposes the use of highly non-Keplerian trajectories enabled by solar radiation pressure and devices with variable area or reflectivity to map and characterize small asteroids. Strategies alternative to hovering involving a combination of retrograde and prograde orbits together with inversions of the orbit direction by either maneuvers or exploiting the natural dynamics are presented and analyzed. As opposed to terminator orbits, this alternating orbiter strategy allows direct overflies of the sub-solar point and other equatorial regions. A simple cost comparison demonstrates a significant improvement with respect to traditional hovering strategies. Additional orbits of interest for hopper spacecraft are also discussed. Finally, various possible implementations of variable area spacecraft that could provide the required SRP control are suggested and discussed.

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Section: VIII Solutions For System Implementationmentioning

confidence: 99%

Alternating Orbiter Strategy for Asteroid Exploration

Yárnoz¹,

Cuartielles

McInnes

2015

Journal of Guidance, Control, and Dynamics

Self Cite

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“…Alternatively, the c.p. is shifted relative to the c.m., such as with moveable vanes [1,2,5,7], membrane twisting/warping and translating [1,2], membrane billowing [8], and changing the local reflectivity [9][10][11]. These methods are limited in their ability to generate SRP attitude control moments [referred to herein as control moment authority (CMA)] because they affect a small portion of the sail's total mass or area and/ or have a limited range of motion.…”

Section: Introductionmentioning

confidence: 98%

Tactics for Heliogyro Solar Sail Attitude Control via Blade Pitching

Guerrant

Lawrence

2015

Journal of Guidance, Control, and Dynamics

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Heliogyros generate attitude control moments by pitching their sail membrane blades collectively or cyclically, similar to a helicopter. Past work has focused on simple blade pitch profiles with the heliogyro normal to the sun; however, most solar sail missions will require sun angles of at least 35 deg. Furthermore, combination pitch profiles (e.g., cyclic plus collective) are needed for attitude control during all mission segments. The control moments for such situations vary in an unintuitive, nonlinear fashion. This paper explores heliogyro control moment authority with varying sun angles and combinations of pitch profiles, providing critical insight for future development of heliogyro attitude control schemes. Three tactics for generating control moments using various profile combinations are introduced for three-axis attitude control during a variety of practical mission scenarios. These tactics indicate that the heliogyro can generate control moments from any orientation, including edge-on to the sun. A restricted, nonlinear, constrained optimization is used to determine the blade pitch profile combination required to generate the desired attitude control torques. This approach could be employed for analyzing mission performance and for designing closed-loop attitude control. Nomenclature A = total sail area, m 2 a xx = collective (where xx equals co), half-p (where xx equals hp), or cyclic (where xx equals cy) profile amplitude, rad, deg D, d x = despun frame F = solar radiation pressure thrust vector, N h = sail membrane thickness, m h = orbit momentum unit vector J n = nth element mass moment of inertia, kg · m 2 M = solar radiation pressure moment vector, N · m, subscript d indicates desired moments N = number of bladeŝ l = local horizontal with respect to sun in orbit plane P = solar radiation pressurê p = reference axis for clock angle δ R = heliogyro blade radius, m S = sun framê s = sun-spacecraft unit vector t = time, s β = blade flap bending angle, rad, deg γ = sail cone angle/Sun angle, angle betweenŝ andd 1 , rad, deg δ = clock angle betweenp andd 3 , rad, deg θ = blade pitch, follows right-hand rule about blade span (radius) axis, rad, deg ϕ xx = half-p (where xx equals hp) or cyclic (where xx equals cy) phase angle, rad, deg χ i = ith blade angle relative to blade 1 in the rotation plane, where χ 1 equals zero, rad, deg Ψ = in-plane moment M 23 azimuth angle, rad, deg ψ i = ith blade azimuth angle in the spin plane, rad, deg Ω = heliogyro inertial spin rate about primary spin axis, rad∕s

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“…Mu proposed to use the RCDs to jointly control the attitude and orbit motion for the spinning sailcrafts (Mu et al , 2015). Borggräfe (Borggräfe et al , 2014) also proposed to use the RCDs to control the sailcraft’s attitude; besides, the RCDs were also used to control the surface shape of the huge flexible membranes to be the required shape (e.g. the paraboloidal shape).…”

Section: Introductionmentioning

confidence: 99%

RBF network based adaptive sliding mode control for solar sails

Lian

Liu

Wang

et al. 2018

AEAT

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Purpose The purpose of this paper is to resolve complex nonlinear dynamical problems of the pitching axis of solar sail in body coordinate system compared with inertial coordinate system. And saturation condition of controlled torque of vane in the orbit with big eccentricity ration, uncertainty and external disturbance under complex space background are considered. Design/methodology/approach The pitch dynamics of the sailcraft in the prescribed elliptic earth orbits is established considering the torques by the control vanes, gravity gradient and offset between the center-of-mass (cm) and center-of-pressure (cp). The maximal torques afforded by the control vanes are numerically determined for the sailcraft at any position with any pitch angle, which will be used as the restriction of the attitude control torques. The finite/infinite time adaptive sliding mode saturation controller and Bang–Bang–Radial Basis Function (RBF) controller are designed for the sailcraft with restricted attitude control torques. The model uncertainty and the input error (the error between real input and ideal control law input) are solved using the RBF network. Findings The finite true anomaly adaptive sliding mode saturation controller performed better than the other two controllers by comparing the numerical results in the paper. The control torque saturation, the model uncertainty and the external disturbance were also effectively solved using the infinite and finite time adaptive sliding mode saturation controllers by analyzing the numerical simulations. The stabilization of the pitch motion was accomplished within half orbit period. Practical implications The complex accurate dynamics can be approximated using the RBF network. The controllers can be applied to stabilization of spacecraft attitude dynamics with uncertainties in complex space environment. Originality/value Advanced control method is used in this paper; saturation of controlled torque of vane is resolved when the orbit with big eccentricity ration is considered and uncertainty and external disturbance under complex space background are settled. Moreover, complex and accurate nonlinear dynamical model of pitching axis of solar sail in body coordinate system compared with inertial coordinate system is provided.

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Distributed Reflectivity Solar Sails for Extended Mission Applications

Cited by 7 publications

References 10 publications

Alternating Orbiter Strategy for Asteroid Exploration

Alternating Orbiter Strategy for Asteroid Exploration

Tactics for Heliogyro Solar Sail Attitude Control via Blade Pitching

RBF network based adaptive sliding mode control for solar sails

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