Space Shuttle Discovery Undocks, Heads Home

Having suffered through multiple launch delays and dodging space debris once finally underway, the Discovery space shuttle March 25 undocked from the International Space Station and began its journey home. The shuttle is expected to land at NASA's Kennedy Space Center in Florida March 28.
After the final transfers of equipment and supplies between Discovery and the ISS and a farewell ceremony between the two crews, shuttle Commander Lee Archambault and station Commander Mike Fincke closed the hatches between the two space vehicles. After the station's Pressurized Mating Adapter 2 pushed the shuttle out in front of the ISS, Discovery took a victory lap around the space station.

While circling the space station, the shuttle's crew got their first full look at the results of the mission's primary goal: delivering and deploying a fourth set of solar array wings. The Discovery crew also delivered a replacement part for the ISS' urine recycling system that converts urine to potable water.

Over three space walks, astronauts installed the solar array, which increases the space station's power by 25 percent. The increased power and operating urine recycling system are necessary to support plans to double the size of the ISS crew from its current three members to six.

"We leave with a sense of accomplishment," Archambault said in a message sent to Mission Control. "It's been a great docked time frame and we look forward to what's next."

Mission accomplished, Discovery fired its thrusters and headed to Earth.

The shuttle also accomplished a crew transfer by delivering Japan's Koichi Wakata to replace NASA Astronaut Sandra Magnus, who served four months aboard the ISS. Wakata joins Fincke and Russian cosmonaut Yury Lonchakov. The Russians are launching a shuttle mission March 26 from Kazakhstan bringing to the ISS Expedition 19 commander Gennady Padalka of Russia, NASA Astronaut Michael Barratt and billionaire Charles Simonyi, who is paying approximately $35 million for the privilege. It will be Simonyi's second trip into space.

The new crew is expected to dock with the ISS shortly before Discovery lands in Florida.

The Discovery launch was delayed by more than a month due to safety concerns about the craft's fuel pressure valves. The final delay came March 11 after NASA detected a leaky GH2 (gaseous hydrogen) vent line. Archambault and his six-person crew finally launched on March 15.

Once under way, the 13-day mission was plagued by orbiting space junk. On March 15, NASA almost rerouted the crew because a breakaway piece of a Russian satellite was likely to come close to the ISS on March 17, just one day before the Discovery was scheduled to dock at the orbiting platform. NASA finally decided to scrub the evasive maneuver.

But after the shuttle mission docked with the ISS, 10-year-old debris from a Chinese satellite forced the crews March 22 to change orbit. The week before Discovery was launched, a piece of a Russian spacecraft motor came close enough to the ISS that the three-man crew was forced to evacuate to the Soyuz TMA-13 capsule, which is attached to the space station to transport astronauts back in an emergency.

"Space debris is becoming an ever-increasing challenge. When it comes to dodging junk, it's a big deal. It's very tiring. Sometimes it's exhausting," said Flight Director Kwatsi Alibaruho.