Finite-Time Spacecraft’s Soft Landing on Asteroids Using PD and Nonsingular Terminal Sliding Mode Control

Table 1

Numerical simulation parameters.

Parameters	Real value	Simulation parameters
Spin period (h)	10.54	10.55
(km)	1.150	1.148
	−0.113	−0.110
	0.0396	0.0397
	0.068	0.069
	0.0032	0.0031
= =		0.0005
= =		0.05
Descending initial position		3550, 4050, 11000
Descending initial velocity		−2.2, 1.2, −9
Landing initial position		300, 300, 2000
Landing initial velocity		−1.2, 0.2, −1
Landing final site		20, 20, 20