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Spacecraft transfer from interplanetary to low near planet orbit by use of aerobraking in Venus’s atmosphere
In framework of the feasibility studies for the Venus-D project several options for placing a spacecraft in a low orbit near a planet orbit were studied.
The goal of these studies is to determine the optimal variant of spacecraft delivery into a near-Venus orbit. The criterion of optimization is the payload mass.
Several scenarios of transfer from interplanetary orbit onto low Venus orbit are considered beginning from the classical method of applying a rocket engine velocity impulse. As an alternative concept the direct entry into atmosphere is analyzed supposing that after atmospheric drag deceleration the spacecraft leaves the atmosphere, achieving an orbit with apocenter above the atmosphere and pericenter below the planet’s surface. By applying appropriate velocity impulses, the spacecraft is finally transferred into low orbit. The problem of optimal control of aerodynamic forces during this maneuver is solved. It is supposed that the lift force during aerobraking maneuver changes its direction by rotating the spacecraft about its longitudinal axis.
Also intermediate methods to reach low orbit are analyzed when initially the spacecraft is transferred into a high elliptical orbit by engine impulse and by later successive comparatively small aerobraking maneuvers. The maximum overload during these maneuvers is determined by the maximum allowed temperature on the surface of the heat shield of the spacecraft.
Comparison of the described methods is presented taking into account the payload mass, technical risks and overall duration of maneuvers.