When did the ship that was commissioned July 1948 with a bow number of ps-31 launch?
CREATE TABLE table_61530 (
    "Bow number" text,
    "Ship name" text,
    "Launched" text,
    "Commissioned" text,
    "Service" text
)
SELECT "Launched" FROM table_61530 WHERE "Commissioned" = 'july 1948' AND "Bow number" = 'ps-31'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: When did the ship that was commissioned July 1948 with a bow number of ps-31 launch? ### Input: CREATE TABLE table_61530 (
    "Bow number" text,
    "Ship name" text,
    "Launched" text,
    "Commissioned" text,
    "Service" text
) ### Response: SELECT "Launched" FROM table_61530 WHERE "Commissioned" = 'july 1948' AND "Bow number" = 'ps-31'