I want to do it without artificial mass

have you tried using sensors and overridden gyroscopes? its fairly possible if that ship is only 50meters away. otherwise you would need to do something slightly more complex. You can also use gravity generators to counter the gravity within your ship. The vanilla gravity generators will not effect your orbit at all and will keep you soundly ground to the floor so you needn't worry about it not being perfectly perpendicular. The issue now is to just keep it perpendicular enough to enter the ship. Maybe use sensors and trigger points near the orbit enough for your sensors to register and turn on some of the gyroscopes that are set on override. Hope this analysis helps