I've reset and have re-done all of the adventures on Mars, but my daily heroic isn't there. I did the heroic a long while back before they removed your ability to get Heroic Adventures manually, dunno if that has any effect. If I can't get this, basically I'm -blam!-ed and can't get the Polaris Lance ever, and I'm out a Powerful Reward, possibly every time there's a flashpoint on Mars. Help of any sort associated with my problem is greatly appreciated.
The daily challenges reset every 4 days. As you completed the daily heroic adventure for last week yesterday, you'll need to wait couple more days for the heroic to be available again.
Have you checked Ana's inventory on the second page to see if she has heroic adventures available for you?