Authorities will try to re-enter the Pike River mine today.
An attempt to go back in the mine two weeks ago was aborted at the last minute after unusual oxygen levels were detected.
Twenty-nine men died after an explosion in the mine on November 19, 2010.
The families of the men who lost their lives will meet at the gate this morning before walking up to the mine, where the concrete seal in the access tunnel will be removed.
Anna Osborne, who lost her husband Milton in the explosion, told TVNZ1's Breakfast today, "I didn’t sleep a wink last night. I'm just so excited that this day is finally here and we can all celebrate this very long road to recovering the drift. I'm just lost for words."
"That darkness of the mine will return to the light and we're waiting for it. Bring it on," she said.
Media will not be present.