Re-entry crews at Pike River are preparing to start drilling through a concrete seal to access the door into the mine's drift.
It's part of a planned mission which will send a recovery crew into the drift next Friday.
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"We've been negotiating this equipment and getting it prepared for about eight months now," says Pike River Recover Agency chief officer Dinghy Pattinson.
"You go back eight years and we left a note to say we would return, and for me this is the first part of that journey really."
Pattinson will lead a three-person team which will enter the mine's drift on May 3.
They will search for any evidence as to what happened on that day in 2010, when a serious of blasts left 29 men dead.
So far, everything's been going well, including a trial of re-introducing fresh air to the drift.
"The trial went really well, we done that last week, we put fresh air into up 180-metres and then since then it's filled back up with nitrogen," Pattinson says.
Everything's being done by the book, and all equipment has to be specially approved.
"At the moment we have an intrinsically safe iPad which will take photographs for us in there," Detective Senior Sergeant Grant Collins says.
Police and the Pike River Recovery Agency have worked out a regimented plan for any evidence that's found.
"The item goes into a sealed bag, into a box which is securely tagged and then at the completion of the shift, the box comes out in the tagged state and handed over to police who then formally take custody of that," Det Snr Sgt Collins says.
The wait is now on as the last of the concrete is drilled away to access the sealed door to the mine's drift.
A door which - once open - will hopefully lead to answers for the families of those 29 men.