public static boolean isSpaceship(Contact contact){
		Object obj = contact.getFixtureA().getBody().getUserData();
		Object obj1 = contact.getFixtureB().getBody().getUserData();
		if(!(obj instanceof BodyData)){
			System.err.println("Collision: Fixture A, "+contact.getFixtureA()+", does not have BodyData! Abort!");
			return false;
		}
		if(!(obj1 instanceof BodyData)){
			System.err.println("Collision: Fixture B, "+contact.getFixtureA()+", does not have BodyData! Abort!");
			return false;
		}
		BodyData a = (BodyData) obj;
		BodyData b = (BodyData) obj1;
		if(a.store != null && b.store != null)
			if(a.store.equals(b.store))
				return true;
		return false;
	}