How to unlock all moon missions Destiny PS3?
You've kind of answered your own question - you cannot play the Taken King missions without the Taken King DLC. As for the regular missions, make sure you've done everything you can up to that point. Maybe you have to go to the Tower before you go to do that mission, so try that. Also check if there was any more Earth missions you may have missed, as you might be expected to complete the Earth missions before going further on the Moon. The only other thing I can think of is do all the Strikes that you have available as well. Hope this helps!