The Heroic Missions require you to have the grade seven gear
You'll find 2875 threads that prove it's not true.
For the fun of a railroad shooter, the difficulty of the missions, the gear required and the reward I can't see what the point of these missions was. And this is all we have to look forward to over the holiday season and likely for the next 9 weeks. What was the plan?
Point - deliver diffcult mission that will take even experienced player at least few attempts to succed.