Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_73 (launch_failures INTEGER, launched VARCHAR, not_usable VARCHAR)
### Question:
What is the total launch failures when there are 4 launches, and the not usable is greater than 0?
### Answer:
SELECT SUM(launch_failures) FROM table_name_73 WHERE launched = 4 AND not_usable > 0