Board Thread:Questions and Answers Forum/@comment-2605:E000:8551:4400:6CEC:BCE4:A405:F4D-20170727001406/@comment-26355186-20170727115945

First of all, you need to complete the entire The Taken King quest. Once you've done that, you should recieve a quest that allows you to play the mission Dread Patrol. Completing Dread Patrol will unlock patrol on the Dreadnaught.