The heavy cruiser remained in Pearl Harbor only until the 30th. On that day, she returned to sea with the hastily repaired "Yorktown" to prepare to meet yet another major thrust by the Japanese fleet – this one aimed at Midway. Air searches from that island spotted the enemy's Midway Occupation Force – made up of transports, minesweepers, and two seaplane carriers – early on 3 June, but the enemy carrier force eluded detection until early in the morning of the 4th. The heavy cruiser screened "Yorktown" as the carrier began launching strike aircraft at about 0840. While the planes droned off to make their contribution to the destruction of the Japanese carrier force, "Astoria" and her colleagues prepared for the inevitable Japanese reply.