Design considerations for Surveyor guidance

Abstract

Jub 65The Surveyor l u n a r s o f t landing s p n c e c r a f t w i l l provide preliminary unmnr,ed s c i e r k i f i c e x p l o r a t i o n of t h e s u r f a c e of t h e moon. d i s z u s s i o n of t h e p e r t i r e n t design c o n s i d e r a t i o n s f o r midcourse guidance and

Landing Trajectory Generation and Energy Optimization for Unmanned Lunar Mission

“…Since the moon is extensively observed as the first step from the Earth to space, numerous aerospace organizations have initiated several scientific operations towards the lunar expedition. Indeed, moon exploration and other planetary investigation concerns have acknowledged significant consideration from the 1960s [1][2][3][4]. Low-energy landing trajectory generation is an important issue for the upcoming space survey operations to accomplish different landing missions on planets, comets, and asteroids with numerous standards [5][6][7][8][9][10].…”

Analytical Landing Trajectories for Embedded Autonomy

“…To design the guidance and control law, two factors should be taken into consideration to ensure missions success: a low touch-down velocity and a vertical attitude on the planetary surface. Many studies on guidance for soft landing have been reported [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. These guidance laws can be divided into two catalogues.…”

“…Gravity-turn guidance law [1][2][3][4][5][6][7][8][9][10]12]: such a descent profile requires that the vehicle thrust vector is oriented opposite to the instantaneous velocity vector along the descent trajectory. To develop a gravity-turn guidance law, an approximate form solution is first required [1][2][3][4], and a control law is then designed to track this predefined profile [3][4][5][6][7][8][9]. The following methods have been developed successfully: linear feedback control [5,6], nonlinear control via non-linear transformation [7], direct adaptive control (DAC) [8], feedback linearization [9] and methods using Lyapunov stability theory [3,4].…”

“…To develop a gravity-turn guidance law, an approximate form solution is first required [1][2][3][4], and a control law is then designed to track this predefined profile [3][4][5][6][7][8][9]. The following methods have been developed successfully: linear feedback control [5,6], nonlinear control via non-linear transformation [7], direct adaptive control (DAC) [8], feedback linearization [9] and methods using Lyapunov stability theory [3,4]. Gravity-turn descent has been used in practice for terminal descent to planetary surface [8].…”

“…Gravity-turn descent has been used in practice for terminal descent to planetary surface [8]. An important benefit of gravity-turn descent is that the landing is assured to be vertical [6]. This guidance law, however, is not derived from optimal control theory, thus fuel consumption is not minimum [10].…”