2013-06-12 According to an article in The Los Angeles Times (June 10, 2013) by W.J. Hennigan:
An F-35 fighter jet launched a missile in mid-flight from its internal weapons bay for the first time in a test flight for the Air Force.
The missile firing took place last week about 60 miles northwest of Los Angeles at the Navy’s Point Mugu Sea Test Range after the plane took off from Edwards Air Force Base. It is a milestone that paves the way for targeted launches later this year.