Astronauts Successfully Install Station Cooling Tank

The old ammonia tank hangs near the spacewalkers today. (NASA)

Shuttle Discovery astronauts Rick Mastracchio and Clay Anderson fought hard to tighten down hold down bolts on a new cooling tank aboard the International Space Station this morning.

Working at the Starboard Truss segment 1, the station's robotic arm slowly moved a new ammonia tank over to the waiting astronauts so that they could bolt it down in place.

As Anderson began installing four bolts at 5:05 am EDT, however two would simply would not align up so that he could torque them down.

The space walkers tried different approaches as they struggled to tighten bolt number one. Frustration began to takeover on the space walkers an hour after first trying to get the tank bolted down.

Inside the space station, Discovery crew mate and coordinator of today's 142nd orbital walk to service the station, Dorothy Metcalf-Lindenburger, gave the crew advice and procedures to assist the pair.

Anderson even went back back to the airlock to retrieve a few extra tools.

Ninety minutes after starting the task, Anderson belted a "come on baby" as he successfully tightened down one and then two of the bolts.

The 1700-pound ammonia tank began to take root on the space station.

Anderson and Mastracchio then plugged in the tanks two electrical connections.

However, the longer than planned bolt down forced NASA to scrub connecting the fluid and nitrogen umbilical during this second of three planned orbital walks by the pair.

That task along with one other planned for today will be added to the final Extra Vehicular Activity or spacewalk planned for Tuesday morning.

As the EVA wrapped up, Metcalf-Lindenburger gave the space walkers praise for the hard work today, "You guy did a great job -- it was a long, long day. You did a great job".

Today's spacewalk concluded at 8:56 am EDT, as the astronauts began to repressurize the American Quest airlock following a seven hour and 26 minute longer than planned excursion.

Twelve minutes later, the hatches leading into the space station were opened, and the spacewalkers were safely inside as they began to doff their white suits.

Today's spacewalk was the fifth by both Anderson and Mastracchio, who now each total just over 32 hours outside a speeding spacecraft. The pair have spent nearly 14 hours working in the vacuum of space during the flight of Discovery.