Solar sailing is an elegant form of space propulsion that reflects solar photons to produce thrust. Different sail configurations exist, including a traditional flat sail (either square- or disc-shaped) and a heliogyro, which divides the sail membrane into a number of long, slender blades, analogous to a helicopter rotor. The magnitude and direction of the induced thrust force depends on the sail’s attitude with respect to the Sun, i.e. on the cone angle. At each cone angle, a flat sail can only generate force of particular magnitude and direction, while this paper demonstrates that a heliogyro can arbitrarily reduce the magnitude of the thrust vector through the additional control of pitching the blades. This gives the heliogyro more force control authority, which is exploited in this paper for orbital control. A linear-quadratic regulator feedback controller is used to quantify the maximum error in the injection state vector of a solar sail Sun-Earth sub-L1 halo orbit from which the nominal orbit can still be recovered. The conclusion is that approximately an order of magnitude larger error in position and velocity can be accommodated, demonstrating superior capabilities of the heliogyro over a flat sail for orbital control.@en

Solar sailing is an elegant form of space propulsion that reflects solar photons off a large membrane to produce thrust. Different sail configurations exist, including a traditional fixed polygonal flat sail and a heliogyro, which divides the membrane into a number of long, slender blades. The magnitude and direction of the resulting thrust depends on the sail’s attitude with respect to the sun (cone angle). At each cone angle, a fixed polygonal flat sail can only generate force constrained to a particular magnitude and direction, whereas the heliogyro can arbitrarily reduce the thrust magnitude through the additional control of pitching the blades. This gives the heliogyro more force control authority, which is exploited in this paper for orbital control of solar sail, sun–Earth, sub-L 1 halo orbits through a linear-quadratic regulator feedback controller. Two test cases are considered, quantifying either the maximum error in the injection state or the maximum delay in solar sail deployment due to deployment failure at injection from which the nominal orbit can still be recovered. This paper finds that the heliogyro can accommodate approximately an order of magnitude larger injection error than a fixed polygonal flat sail and a significantly larger sail deployment delay of up to 20.2 days in some cases.@en

A heliogyro is a solar sail concept that divides the solar sail membrane into a number of long, slender blades of film extended from a central hub, maintained in a flat state through spin-induced tension. The heliogyro can redirect and scale the solar radiation pressure (SRP) force and can achieve attitude control by twisting the blades, similar to a helicopter rotor. Different pitch profiles exist, including pitching the blades in a collective, cyclic or combined collective and cyclic manner. While the forward mapping, i.e., computing the SRP force and moment generated by the heliogyro for a given pitch profile, is straightforward, the inverse of the problem is much more complex. However, this inverse problem (finding the blades’ pitch that results in a desired SRP force and/or moment) is crucial for heliogyro mission design and operations. This paper therefore solves the inverse problem numerically: first, only for a desired SRP force or SRP moment and subsequently for the fully coupled inverse problem. The developed methods are subsequently applied to track a reference trajectory that corrects for injection errors into a solar sail Sun-Earth sub-L1 halo orbit. I. Introduction@en