Today's re-entry into the Pike River mine is being seen as sensible.

An attempt to go into the mine was cancelled at the last minute earlier this month, over problems with gas monitoring equipment.

The families will be there this time, but no dignitaries or media are allowed.

Canterbury University geology professor David Bell told Mike Hosking it sounds like they're going up to the 170 metre seal in the short term.

He says it's a big challenge but it's being managed in a very sensible and appropriate manner.