Scientists describe deployment of three-body chain-type tethered satellites in low-eccentricity orbits
Recently, the tethered satellite system (TSS) has been used in Earth observations, space interferometry and other space missions, due to its potential merits. The tethered TSAR (tomographic synthetic aperture radar) system ...
Successful deployment is critical for TSAR tethered systems.
Several control methods, including length, length rate, tension, and thrust-aided control, have been proposed over the years. Among them, adjusting tension is a viable yet challenging approach due to the tether's strong nonlinearity and underactuated traits.
Current tether deployment schemes focus on two-body TSS, with little emphasis on multi-TSSs. In a research article recently published in Space: Science & Technology, a research team led by Zhongjie Meng from Northwestern Polytechnical University has developed a new deployment strategy for a 3-body chain-type tethered satellite system in a low-eccentric elliptical orbit.
Several control methods, including length, length rate, tension, and thrust-aided control, have been proposed over the years. Among them, adjusting tension is a viable yet challenging approach due to the tether's strong nonlinearity and underactuated traits.
Current tether deployment schemes focus on two-body TSS, with little emphasis on multi-TSSs. In a research article recently published in Space: Science & Technology, a research team led by Zhongjie Meng from Northwestern Polytechnical University has developed a new deployment strategy for a 3-body chain-type tethered satellite system in a low-eccentric elliptical orbit.
First, authors establish the motion model of a 3-body chain-type TSS in a low-eccentric elliptical orbit. Two assumptions are made: (a) the tethers are massless; (b) only the planar motion is considered. The proposed model consists of 3 point masses (m1, m2, and m3) and 2 massless tethers (L1 and L2).
The orbit of m1 is defined by its orbital geocentric distance r and true anomaly α; the position of m2 relative to m1 is determined by tether L1 and in-plane libration angle θ1; the position of m3 relative to m2 is determined by L2 and θ2.
The orbit of m1 is defined by its orbital geocentric distance r and true anomaly α; the position of m2 relative to m1 is determined by tether L1 and in-plane libration angle θ1; the position of m3 relative to m2 is determined by L2 and θ2.
Model of 3-body chain-type tethered satellite system. Credit: Space: Science & Technology
Schematic of the deployment control framework. Credit: Space: Science & Technology
Error and tension integral in Schemes 2 and 3. Credit: Space: Science & Technology