Analytic Initial Relative Orbit Solution for Angles-Only Space Rendezvous Using Hybrid Dynamics Method

A closed-form solution to the angles-only initial relative orbit determination(IROD)problem for space rendezvous with non-cooperated target is developed,where a method of hybrid dynamics with the concept of virtual formation is introduced to analytically solve the problem.Emphasis is placed on developing the solution based on hybrid dynamics(i.e.,Clohessy-Wiltshire equations and two-body dynamics),obtaining formation geometries that produce relative orbit state observability,and deriving the approximate analytic error covariance for the IROD solution.A standard Monte Carlo simulation system based on two-body dynamics is used to verify the feasibility and evaluate the performance proposed algorithms.The sensitivity of the solution accuracy to the formation geometry,observation numbers is presented and discussed.

China Accomplished Its First Space Rendezvous and Docking

At 1:36 am on November 3,China's Shenzhou 8 unmanned spaceship and Tiangong 1 space lab spacecraft accomplished the country's first space docking procedure and coupling in space at more than 343km above Earth's surface,marking a great leap in China's space program.

Survey of orbital dynamics and control of space rendezvous

Rendezvous orbital dynamics and control （RODC） is a key technology for operating space rendezvous and docking missions. This paper surveys the studies on RODC. Firstly, the basic relative dynamics equation set is introduced and its improved versions are evaluated. Secondly, studies on rendezvous trajectory optimization are commented from three aspects： the linear rendez- vous, the nonlinear two-body rendezvous, and the perturbed and constrained rendezvous. Thirdly, studies on relative navigation are briefly reviewed, and then close-range control methods including automated control, manual control, and telecontrol are analyzed. Fourthly, advances in rendezvous trajectory safety and robust analysis are surveyed, and their applications in trajectory optimization are discussed. Finally, conclusions are drawn and prospects of studies on RODC are presented.

Study on Forced Straight-Line Guidance for the Final Translation Phase of Spacecraft Rendezvous

Aimed at the problem of final translation of space rendezvous for the applications such as docking,inspection and tracking,optimal straight-line guidance algorithm based on pulse/continuous low-thrust in the context of Clohessy-Wiltshire dynamics is proposed.Two modes of guidance strategy:varying-speed and fixed-speed approaching scheme for V-bar and R-bar approach by using constant/finite low-thrust propulsion respectively are studied,and the corresponding fuel-optimal conditions are obtained.Numerical simulation is conducted to verify and test the proposed algorithms.The results show that there is generally no different between the fuel consumptions by using the two different approaching modes for V-bar case.However,the conclusion for Rbar case is different that the using of continuous low-thrust cost more fuel and transfer time.