HR contacts generally after a cap of two weeks, best to call after a week and a half to show you are still interested; then you go in for an aptitude test (pretty basic test). After passing the test you meet the possible Managers and Supervisors of the area you applied for(for me it was 4 managers of different sections of the Propulsion department). After about a week HR will contact you if you were selected by a Manager to be hired on.