function Spaceship.stop_integrity_check(spaceship)
  spaceship.check_flash_alpha = nil
  spaceship.is_doing_check = nil
  spaceship.is_doing_check_slowly = nil
  spaceship.check_stage = nil
  spaceship.pending_tiles = nil
  spaceship.streamline = nil
  if spaceship.integrity_valid and spaceship.check_tiles then
    -- success
    spaceship.count_empty_tiles = spaceship.check_count_empty_tiles
    spaceship.check_count_empty_tiles = nil

    spaceship.known_tiles = table.deepcopy(spaceship.check_tiles)
    spaceship.check_tiles = nil

    -- get the average for surface transfer
    local min_x = nil
    local max_x = nil
    local min_y = nil
    local max_y = nil
    local floor_tiles = 0
    local bulkhead_tiles = 0
    local front_tiles = {} -- x:y
    for x, x_tiles in pairs(spaceship.known_tiles) do
      if min_x == nil or x < min_x then min_x = x end
      if max_x == nil or x > max_x then max_x = x end
      for y, status in pairs(x_tiles) do
        if status == Spaceship.tile_status.floor_console_connected
          or status == Spaceship.tile_status.bulkhead_console_connected then
            if min_y == nil or y < min_y then min_y = y end
            if max_y == nil or y > max_y then max_y = y end
            if status == Spaceship.tile_status.floor_console_connected then
              floor_tiles = floor_tiles + 1
            else
              bulkhead_tiles = bulkhead_tiles + 1
            end
            if (not front_tiles[x]) or y < front_tiles[x] then
               front_tiles[x] = y
            end
        end
      end
    end
    max_x = max_x + 1 -- whole tile
    max_y = max_y + 1 -- whole tile
    spaceship.known_floor_tiles = floor_tiles
    spaceship.known_bulkhead_tiles = bulkhead_tiles
    spaceship.known_bounds = {left_top = {x = min_x, y = min_y}, right_bottom={x = max_x, y = max_y}}
    spaceship.known_tiles_average_x = math.floor((min_x + max_x)/2)
    spaceship.known_tiles_average_y = math.floor((min_y + max_y)/2)
    local front_tiles_by_y = {} -- y:count
    local front_tiles_by_y_left = {} -- y:count
    local front_tiles_by_y_right = {} -- y:count
    local max_flat = 0
    for x, y in pairs(front_tiles) do
      front_tiles_by_y[y] = (front_tiles_by_y[y] or 0) + 1
      if front_tiles_by_y[y] > max_flat then
        max_flat = front_tiles_by_y[y]
      end
      if x < spaceship.known_tiles_average_x then
        front_tiles_by_y_left[y] = (front_tiles_by_y_left[y] or 0) + 1
      else
        front_tiles_by_y_right[y] = (front_tiles_by_y_right[y] or 0) + 1
      end
    end
    local width = max_x - min_x
    -- max_flat == width = 0
    -- max_flat == width / 3 = 1
    local streamline_flatness = math.min(1, (1 - (max_flat-2) / (width-2)) * 1.5)
    local streamline_left = math.min(1, 2 * (table_size(front_tiles_by_y_left)-1) / (math.max(0.5, (width-1) / 2.5)))
    local streamline_right = math.min(1, 2 * (table_size(front_tiles_by_y_right)-1) / (math.max(0.5, (width-1) / 2.5)))
    spaceship.streamline = (streamline_flatness + streamline_left + streamline_right
      + 3 * math.min(streamline_flatness, math.min(streamline_left, streamline_right))) / 6
    --spaceship.streamline = math.min(1, 3.5 * (table_size(front_tiles_by_y)-1) / width)
    -- if it is symetrical then 1/2 would be max (excluding the -1)
    -- use 1/3.5 as max so there can be a few flat areas
    Log.trace("streamline flat "..streamline_flatness.." left "..streamline_left.." right "..streamline_right)
    --Log.trace("streamline "..spaceship.streamline )
    if Spaceship.is_on_own_surface(spaceship) then
      Spaceship.find_own_surface_engines(spaceship)
    end
  else
    spaceship.integrity_valid = false
    spaceship.check_tiles = nil
    spaceship.check_message = {"space-exploration.spaceship-check-message-failed-empty"}
  end

  --spaceship.check_message = nil
  if spaceship.console and spaceship.console.valid then
    --spaceship.console.force.print("Spaceship integrity check complete.")
  end

  Spaceship.check_integrity_stress(spaceship)

  if spaceship.is_launching then
    Spaceship.launch(spaceship)
  end
end