How to keep the camera behind the player at all times.

Ok thanks to prosoft i am really understanding panda3d and the scene graph. And so i have a ship and i put the camera behind it.

camera.setPos(0 , playerShip.ship.getY() - 30, 0)   

and this worked, until i rotated the player a bit:

playerShip.ship.setHpr(0,90,0)

it is still close to the player but its not behind the ship it is in the same position it would be if the ship were still facing forward. How can i fix this?

reparentTo the camera to the player?