When did the ATV that deorbited on 29 september 2008, launch?
CREATE TABLE "atv_missions" (
  "designation" text,
  "name" text,
  "launch_date" text,
  "iss_docking_date" text,
  "deorbit_date" text
);
SELECT "launch_date" FROM "atv_missions" WHERE "deorbit_date"='29 september 2008';