The two crews working side by side aboard the space shuttle Discovery and the international space station opened up the pressurized Leonardo supply module today, as they prepare to transfer its cargo over to station.
Leonardo was firmly docked to the station's Harmony port late on Monday.
Following pressurization of the module and checks for leaks around the seals, the crews opened the hatch to the equipment module 90 minutes ahead of schedule at 11:54 pm EDT.
Beginning after the crew wakes to start their fifth day in space this afternoon EDT, they will begin slowly transferring both small packages and large equipment racks from Leonardo to areas around the space station for storage.
Overnight, this reporter spoke with space station flight director Ron Spencer at the Johnson Space Center, and I asked him "how will the crew store large equipment from the Leonardo - which are destined for Tranquility - in the station for six months":
"As we continue to fly more and more shuttle missions to station, station is getting a lot fuller.
Storage is a challenge right now. Luckily for this mission, we still have enough empty spots to store hardware which is destined for the modules right now. But in a couple more shuttle flights from now this will be more of a problem."
Between this flight of Discovery and the arrival on the Tranquility module six months from now, several racks and a huge treadmill known as COLBERT, will be in a temporary storage site aboard station.
Spencer added, "It's kind of a shell game as to where to put all these empty racks; but right now, luckily, we have enough empty slots available."
Also today, newly arrived space station flight engineer Nicole Stott and Discovery mission specialist Danny Olivas will head out of the Quest airlock to begin a 6 1/2-hour spacewalk.
The spacewalk is scheduled to start at 5:49 pm, however this flight has been a mission which is always ahead of their timeline.
Their prime goal during the orbital walk will be the removal of several bolts attaching a nearly dry ammonia tank in preparation for it's removal on Thursday evening.
In a bit of good news for the crew of Discovery, the craft's thermal protection system has been cleared for reentry follow detailed camera surveys on Sunday. The crew will still perform a prelanding late inspection of the orbiter's tiles to look for micrometeorites impacts which may occur as it sits docked with station this week.