Aspace explorer is moving through space far from any planet or star. he notices a large rock, taken as a specimen from an alien planet, floating around the cabin of the ship. should he push it gently or kick it towards the storage compartment

My suggestion would be to push the rock gently in the direction
he wants it to go.  If he kicks it, then he could injure his toe, and
the large rock might take off in the direction of a vital control panel
or navigation component.  By pushing it gently, he can give it a small
acceleration, assuring that it won't become a dangerous missile, and
he can control it with greater accuracy.  There's no reason for the explorer
to be in a hurry.  Does he have places to go ?  Appointments to keep ? 
Where can he go ?  He's in space !  Relax !  Take care of the rock safely.