 On reaching orbit some tiles were visibly missing around the tail of the Shuttle, and fears that the more-critical tiles on the underside of the vehicle were damaged led to a hastily arranged effort to use KH-11 KENNEN spy satellites and the Kuiper Airborne Observatory to acquire imaging of the Shuttle in orbit to assess the damage.Fortunately, the damage was minimal, and the mission concluded safely.Much later, missing tiles caused the Space Shuttle Columbia disaster in 2003.