The Pentagon will need to put off moving the F-35 program to full-rate production due to another delay in starting critical simulations tests. Top weapons buyer for the Defense Department, Ellen Lord, cannot clear the F-35 for full-rate production, also called Milestone C, until the jet goes through a series of tests in the Joint Simulation Environment (JSE). An F-35A flies over Utah (Photo Courtesy U.S. Air Force) The testing and $398 billion production program have been postponed from December 2020 to sometime in 2021 due to difficulties finishing technical preparations, according Lord's spokesperson, Jessica Maxwell. Tests at JSE simulate a range of high-threat scenarios that can't be replicated in live flight tests. Had testing begun in December, it would have taken an addition two to three months to analyze the data and draft a final report to the Pentagon by March 2021. Now, with both testing and production delayed, the team is "preparing an updated project schedule