In manned/crewed spacecraft missions, can a spacecraft remain stationary i.e. not moving once launched in sky & space similar to a Helicopter and not that of a aeroplane?
Only by using fuel.
Without engines operating, any spacecraft (or object) is in "free fall" - it's path is controlled by the gravity of other bodies.
If that path is an orbit and outside atmosphere, it may be a stable situation, but it's then not stationary.
Likewise if it is in a Lagrange point of another body in orbit.
Otherwise it is accelerating towards whatever body or bodies have the most gravitational influence.