Brief update from ESA’s Mike Steinkopf at ATV-CC a few moments ago:
Today, the ATV hatch was opened again. Crew had to preform the ATV-to-Service Module (SM) interface leak check and repressurization.
Then, they first opened the SM hatch (on the ISS side) followed by opening of the ATV Hatch. This activity finished the ‘mid-mission isolation’, which began on Sunday by hatch closing as standard procedure for Monday’s EVA (see our earlier posts below for details).
ATV is again open for further crew utilisation!