Astronauts wrap up equipment transfers; hatches closed for undocking Monday

Editor's note...
  • Posted at 05:30 AM, 03/06/11: Astronauts wrap up equipment transfers; hatch closing on tap
  • Updated at 04:25 PM, 03/06/11: Farewell ceremony; hatch closure
CBS News

After transferring a final few items to and from the International Space Station -- and enjoying a bit of zero-gravity fun in a roomy new storage module -- the Discovery astronauts bid their station colleagues farewell Sunday, floating back aboard the orbiter to rig the ship for undocking early Monday to wrap up the shuttle's 13th and final visit.

Space station commander Scott Kelly, left, shakes hands with Discovery skipper Steven Lindsey shortly before the shuttle crew left the lab complex to prepare for undocking Monday. (Photo: NASA TV)
During a brief farewell ceremony in the U.S. Destiny laboratory module, Discovery commander Steven Lindsey thanked Expedition 26 commander Scott Kelly for the lab crew's hospitality during an extended eight-day visit.

"Scott, it was a pleasure being up here, we appreciate your hospitality, we appreciate your putting up with us knocking your stuff off the walls and generally trashing your station, doubling the number of people," Lindsey said. "On behalf of the crew, we had a great time, we appreciated the hospitality, enjoyed the crew meals together and we're going to miss you guys. So thanks for everything."

Kelly said the station crew "really enjoyed having guests."

"This is the first group of guests I've had in about 150 days," he said. "We're going to miss you but most of all, we're going to miss Discovery. Discovery has been a great ship and has really supported the International Space Station, more so than, I think, any other space shuttle. We wish her fair winds and following seas."

As the shuttle crew floated forward, through the Harmony module and into the hatchway leading to Discovery, space station Flight Director Royce Renfrew called from mission control in Houston to tell the astronauts "it's been an honor and a privilege to work this mission with you."

"A couple of folks have asked me recently what I would feel at this moment, and I think the answer is I just feel really proud to take Discovery home at the very top of her game," he said. "And a lot of the credit goes to the on-board crew. You guys rock."

Hatches between the space station an Discovery were closed at 4:11 p.m.

Shuttle commander Steven Lindsey shakes hands with cosmonaut Dmitry Kondratyev before leaving the station. (Photo: NASA TV)
The combined crews finished their resupply transfer work earlier Sunday and shared a final joint meal before the shuttle astronauts took a break to relax and enjoy the view. Shortly before the farewell ceremony, several shuttle astronauts could be seen frolicking in the newly installed Permanent Multipurpose Module, spinning about, cartwheeling and running around the walls.

"It looks like there's people playing hamster wheel in the PMM, so be careful when you go in there," mission control communicator Stan Love jokingly radioed station flight engineer Catherine "Cady" Coleman.

Discovery's crew delivered the 21,817-pound Permanent Multipurpose Module, loaded with supplies and equipment, to the space station and a 7,611-pound external cargo platform carrying a spare set of radiator panels. The astronauts also transferred another 2,031 pounds of equipment from the shuttle crew cabin to the station and delivered 853 pounds of water, 112 pounds of nitrogen and 182 pounds of oxygen. Another 2,599 pounds of equipment and experiment samples were moved from the station to Discovery for return to Earth.

In addition to the crew's resupply work, astronauts Alvin Drew and Stephen Bowen staged two successful spacewalks to carry out a variety of maintenance chores outside the lab complex.

"The shuttle crew's doing great, the station crew is doing great, the vehicles are in great shape and all in all, we couldn't be more pleased with how this mission is going," said shuttle Flight Director Bryan Lunney.

Lunney, the son of legendary Apollo flight director Glynn Lunney, faces his final shift Monday. With the shuttle program winding down, Lunney is leaving NASA to take a job in private industry. Asked if Discovery's final undocking might prompt an emotional moment in mission control, Lunney said the focus will remain squarely on carrying out the remainder of the mission.

"For us on console, it's stick with business, take care of the crew, take care of the vehicle, make sure everything's going well," he said. "The emotion may kick in later after we unplug for our last shift. Tomorrow will be my last shift and afterwards, perhaps it'll be a little emotional. But for the most part, we'll just be excited the mission has gone so darn well."

Space station commander Mark Kelly spins up shuttle astronaut Nicole Stott during a bit of off-duty fun Sunday. (Photo: NASA TV)
Along with delivering needed supplies and equipment to the station, the combined crews also performed needed maintenance on the station's oxygen generator and one of its carbon dioxide removal systems.

Kelly worked earlier Sunday to remove maintenance equipment from the oxygen generation assembly in the U.S. Tranquility module after work Saturday to adjust the chemistry of supply water and to install a filter intended to prevent particulates from clogging internal components.

The OGA works by using electricity to break water down into hydrogen and oxygen. The device was activated briefly Saturday after the filter was installed to collect water samples that will be returned to Earth aboard Discovery for detailed analysis. If the water meets specifications, the OGA will be returned to normal operation in the near future.

The astronauts also serviced a carbon dioxide removal assembly in the U.S. Destiny laboratory module Saturday, carrying out a bit of electronic surgery to bypass a short circuit in a heater assembly. The repair work went well and Edelen said the device appeared to be working normally.

With hatch closure, the shuttle astronauts now will turn their attention to undocking Monday at 7 a.m. It will be Discovery's 13th and final departure from the space station as the veteran spaceplane sails into its last three days in space.

With pilot Eric Boe at the controls, Discovery will pull straight away from the station to a point about 400 feet in front of the lab complex. Boe then will guide the shuttle through a 360-degree loop of the station before leaving the area for good around 8:43 a.m. (a detailed undocking timeline is posted on the Flight Data File page).

After a final heat shield inspection Monday, the astronauts will pack up and test the shuttle's re-entry systems Tuesday. Landing back at the Kennedy Space Center to close out Discovery's 39th and final mission is expected just before noon Wednesday.

Here is an updated timeline of the crew's activities for Sunday (in EST and mission elapsed time; includes rev. J of the NASA TV schedule):

03:23 AM...09...10...30...Crew wakeup
04:48 AM...09...11...55...ISS daily planning conference
06:13 AM...09...13...20...EVA reconfigure and transfer
06:33 AM...09...13...40...Transfer operations resume
06:48 AM...09...13...55...ISS: OGA cleanup
08:13 AM...09...15...20...SAFER checkout and swap
10:13 AM...09...17...20...Joint crew meal
11:13 AM...09...18...20...Crew off duty
01:30 PM...09...20...37...Mission status briefing on NTV
01:58 PM...09...21...05...Rendezvous tools checkout
02:33 PM...09...21...40...Oxygen transfer teardown
03:33 PM...09...22...40...Farewell ceremony
03:48 PM...09...22...55...Egress and hatch closure
04:18 PM...09...23...25...Orbiter docking system leak checks
04:33 PM...09...23...40...Centerline camera install
04:38 PM...09...23...45...ISS daily planning conference
06:53 PM...10...02...00...ISS crew sleep begins
07:23 PM...10...02...30...STS crew sleep begins
09:00 PM...10...04...07...Daily highlights reel (repeated hourly)