Modeling of a Forced-Thrust Spacecraft in Re-Entry Phase with 6-DOF ModelConsideration

The key parameters for re-entry spacecraft are velocity and acceleration in the re-entry phase. The system requirements such as aerothermal, health of man and other factors limit velocity and acceleration in the re-entry phase. In this article, a forced-thrust spacecraft is designed and modeled for achieving of the appropriate parameters. Indeed in this paper, it has been tried to design and model the path of a forced-thrust spacecraft in the re-entry phase. The followings have been done, respectively. With considering a 6-DOF projectile which has a forcedthrust for velocity reduction, the environmental conditions are modeled. After calculating aerodynamic coefficients using MISSILE DATCOM the re-entry model of forced-thrust spacecraft is completed by combination of aerodynamic equations and dynamic equations of rigid body motion with effect of forced-thrust. In this paper, thrust with 250 N and in the reverse direction of velocity can brought maximum acceleration to be less than 4g which is very suitable for having a safe trip. Also, as it is suitable to use the least available thrust with respect to mass and technological limitations, in the second step initial flight path angle is changed to achieve the safe maximum acceleration. It is shown that for a low flight path angle (for example, -2.0 degree) maximum acceleration can be controlled using less reverse thrust.

کلیدواژه ها:

re-entry ، forced - thrust ، spacecraft