The hatch between the newly arrived SpaceX Dragon spacecraft and the Harmony module of the International Space Station was opened by NASA Astronaut Don Pettit at 5:53 am EDT Saturday as the station flew 253 miles above Auckland, New Zealand.

The hatch opening begins four days of operations to upload more than 1,000 pounds of cargo from the first commercial spacecraft to visit the space station and reload it with experiments and cargo for a return trip to Earth. It is scheduled for splashdown several hundred miles west of California on May 31.

Wearing protective masks and goggles, as is customary for the opening of a hatch to any newly arrived vehicle at the station, Pettit entered the Dragon with Station Commander Oleg Kononenko. The goggles and masks will be removed once the station atmosphere has had a chance to mix air with the air inside the Dragon itself.

Source: NASA