Mike Steinkopf, Mission Director at ATV-CC, reports that the first ATV-4 O2 transfer took place today:

View showing the gas & water delivery control panel mounted inside ATV and accessible to the crew.

View showing the gas & water delivery control panel mounted inside ATV and accessible to the crew.

For this transfer the ATV Fan was switched ON again. The Fan activation in addition to IMV (Inter Module Ventilation) is mandatory to guarantee a controlled O2 distribution within ATV/ISS. A delta (change in) pressure increase of 9.8 mmHg – corresponding to about 15 kg of O2 – was seen during 1h:25min of transfer time.

This gives some fresh air to the crew!

Tomorrow, there will be the first air delivery from ATV to ISS. (Planned delta pressure of 13mmHg, corresponding to 6.5 kg, during 2h:30)

Note: ATV brought up 33 kg of O2 and 66 kg of Air, which will be transferred in increments during the remaining attached phase of ATV upon request.