If the players exit their ship in Combat Armor (or, if Queen's English speaking, armour), I would assume that the first starport employee to see them would immediate trigger the Emergency Alert Siren and report a pirate raid on the facility. The Starport Authority immediately activates its security forces, dispatches its SWAT team (if it has one), alerts any adjoining Naval and/or Scouts base, and also alerts the planetary authorities to the assumed assault.
As military forces converge on the suspected raiders, action is immediately taken to neutralize the ship from with the characters disembarked, with the aim of gaining control of it so that it may not take off again, and if necessary disabling it by direct attack. Precision shaped charges are used to blast holes in the hull, rendering in no longer air tight and fuel tanks no longer able to contain fuel.
The players wearing Combat Armor as assumed to be raiders, and engaged immediately by the security and military forces, with no attempt at parley, and unless they immediately surrender, they will be killed. If they surrender, they will be treated and tried as piratical raiders, and executed by the local planetary authorities, unless they can convince them of the players complete stupidity. That only keeps them from being executed, but they will be imprisoned for extended terms, and all possessions of theirs seized to recover the costs of the military operation.