Using Shifting Masses to Reject Aerodynamic Perturbations and to Maintain a Stable Attitude in Very Low Earth Orbit
Polat, Halis C.
MetadataShow full item record
The aerodynamic forces are the main orbital and attitude perturbations at very low orbital altitudes ( 450 km). To minimize them, it is desirable to design spacecraft with their center-of-mass (CoM) as close as possible to the spacecraft’s center-of- pressure (CoP). Design constraints, poorly understood aerodynamics and environ- ment variability, prevent this CoP and CoM match. The use of internal shifting masses, actively changing the location of the spacecraft CoM, and thus modu- lating, in direction and in magnitude, the aerodynamic torques is proposed as a method to reject these disturbances. First, the equations of motion of a spacecraft with internal moving parts are revisited. The atmospheric environment and the aerodynamic properties of a spherically shaped spacecraft are then provided. A single-axis controller is used to analyze the disturbance rejection capability of the method with respect to several parameters (shifting mass, shifting range and alti- tude). This analysis shows that small masses and a limited shifting range suffice if the nominal CoM is relatively close to the estimated CoP. For the full three rota- tional degrees-of-freedom analysis, a quaternion feedback controller and a linear- quadratic regulator are used. Finally, a practical implementation on a 3U CubeSat using commercial-off-the-shelf components is provided, demonstrating the tech- nological feasibility of the proposed method.
26th AAS/AIAA Space Flight Mechanics meeting, Napa, California
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Bevilacqua, R.; Romano, M. (2008);In this work, the residual atmospheric drag is exploited to perform rendezvous maneuvers among multiple spacecraft in low Earth orbits. These maneuvers are required, for instance, for autonomous on-orbit assembly. By varying ...
Virgili-Llop, Josep; Polat, Halis C.; Romano, Marcello (www.frontiersin.org, 2019-02);At very low orbital altitudes (?450 km) the aerodynamic forces can become major attitude disturbances. Certain missions that would benefit from a very low operational altitude require stable attitudes. The use of internal ...
Chesi, Simone; Gong, Qi; Romano, Marcello (American Institute of Aeronautics and Astronautics, Inc., 2017-07);This paper proposes a spacecraft attitude control technique based on the use of center-of-mass shifting. In particular, the position vector of the spacecraft’s center of pressure with respect to the center of mass is ...