Calculating reentry conditions for space tether-assisted return system

The atmospheric reentry conditions for a space tether-assisted return system are calculated, and its influence factors are analyzed based on the space tether-assisted deorbit system. The space tether-assisted return process is described, its dynamic model and the backswing model of the capsule in the orbit coordinate system are established, and the results on the calculation of reentry conditions are given. The influence on reentry conditions by tether length, maximum deviation, tether mass, cut angle and the range of tether length that meet the reentry conditions under different altitudes are analyzed. The analytical expression among reentry velocity, altitude and tether length, the expression between maximum deviation angle and tether length and the expression among reentry angle, maximum deviation angle and tether length are obtained. Finally the second order expression between reentry condition and tether length is obtained and verified. This study has reference value for choosing the parameters of a future tether-assisted return system and calculating its return conditions.