Discovery arrives at space station Docking maneuver successfully completed in shuttle's final visit to orbiting laboratory
Radar tracking of Space Shuttle Discovery as it approaches its rendezvous with the International Space Station, Feb. 26, 2011. (NASA TV)
Space Shuttle Discovery as seen from the International Space Station during preparations for docking, Feb. 26, 2011. (NASA)
(CBS News)
Last updated 2:53 p.m. ET
The shuttle Discovery glided to a picture-perfect docking with the International Space Station Saturday - the veteran spaceplane's 13th and final linkup with the orbiting outpost.
With commander Steven Lindsey manually flying Discovery from the aft flight deck, the shuttle's payload bay docking system engaged its counterpart on the front end of the station's Harmony module at 2:14 p.m. EST (GMT-5), reports CBS News space consultant William Harwood.
"Station and Houston, Discovery has capture confirmed," an astronaut radioed.
The historic linkup marked the first time in the station's 12-year history that spacecraft from the United States, Russia, the European Space Agency and Japan were docked at the outpost at the same time.
Final launch of Space Shuttle Discovery
CBS News' Space Place (Harwood blog)
NASA's Space Shuttle Mission Home Page
Later in the mission, if all goes well and mission managers concur, three station crew members will undock in a Russian Soyuz spacecraft to photograph the lab complex and all the visiting vehicles from afar, capturing a unique moment that, with the shuttle's looming retirement, will never be repeated.
But first, the combined crews have to accomplish the primary objectives of Discovery's mission, including attachment of a final U.S. module, loaded with critical supplies and equipment, and an external storage platform carrying a spare set of radiator panels.
A few minutes after 1 p.m., Lindsey and pilot Eric Boe brought Discovery to a halt about 600 feet directly below the space station. At that point, Lindsey conducted a computer-assisted 360-degree back-flip maneuver, exposing the shuttle's belly and critical heat-shield tiles to the crew aboard the station.
Expedition 26 flight engineers Catherine "Cady" Coleman and Paolo Nespoli filmed the maneuver, using 400 mm and 800 mm telephoto lenses respectively, to capture high-resolution photographs of Discovery's heat shield tiles. The images will be downlinked to analysts in mission control at the Johnson Space Center for detailed evaluation.
During Discovery's launching Thursday, several pieces of foam insulation fell away from the ship's external tank, including some that appeared to contact the shuttle's heat shield. The foam shedding occurred well after the first two minutes and 15 seconds of flight when the dense lower atmosphere can cause debris to hit with a high relative velocity.Engineers do not believe the foam lost Thursday caused any significant damage, but the photos shot during final approach Saturday will be carefully scrutinized to make sure, and to look for anything else that might need attention.
After the rendezvous pitch maneuver, Lindsey carefully guided Discovery to a docking at pressurize mating adapter No. 2 on the front end of the station's Harmony module. It was Discovery's 13th and final docking with the International Space Station.
If all goes well, hatches between Discovery and the station will be opened shortly after 3:30 p.m. and Expedition 26 commander Scott Kelly, Alexander Kaleri, Oleg Skripochka, Dmitry Kondratyev, Catherine Coleman and Paolo Nespoli will welcome Lindsey and his shuttle crewmates - pilot Eric Boe, Al Drew, Stephen Bowen, Michael Barratt and Nicole Stott - into the space station.
After a mandatory safety briefing, the shuttle astronauts will get to work transferring spacesuits and other gear to the station. Barratt and Stott, operating the station's robot arm, plan to pull a cargo pallet out of Discovery's cargo bay just before 5 p.m. The pallet, known as external logistics carrier No. 4, is loaded with a spare set of radiator panels for the station's ammonia cooling system.
ELC-4 will be mounted on the underside of the station's right-side solar power truss. To get it there, Barratt and Stott will hand it off to the shuttle's robot arm, operated by Boe and Drew. The station arm then will be repositioned, inchworm fashion, moving from the Harmony module to its mobile base work station. When the move is complete, the shuttle arm will hand ELC-4 back to the station arm and the pallet will be mounted on the solar power truss for future use as needed.
A mission status briefing is planned for 4:30 p.m. The crew will go to bed shortly before 11 p.m.
The , flying the  mission, has successfully rendezvoused and docked with the International Space Station (ISS) today at 18:14 UTC for what is scheduled to be the final time in its career.

The  ''(pictured docked to ISS)'' has docked with the International Space Station for what is scheduled to be the final time on the  mission today. 
Official STS-133 crew portrait. From left to right: Alvin Drew, Nicole Stott, Eric Boe, Steven Lindsey, Michael Barratt and Steve Bowen 

''Discovery'' is delivering six astronauts to the orbiting outpost, as well as station parts and supplies including the , the  and , the first dexterous humanoid robot in space.

The docking, ''Discovery'''s 13th and final scheduled docking, occurred two minutes ahead of schedule, having been originally scheduled for 19:16 GMT today.

The hatch between the space shuttle and the ISS was opened at 20:16 UTC, after which the crew members of  welcomed the crew of STS-133 aboard the station. The crew then participated in a safety briefing with Expedition 26 commander , while Shuttle Flight Director Bryan Lunney took part in a mission status briefing on the ground which began at 20:50 UTC.

Later on today, crew members  and  are scheduled to move the ExPRESS Logistics Carrier-4 from the payload bay using the shuttle's robotic arm to the station's own robot arm for placement on the exterior of the orbital laboratory.

There was a delay in the docking mechanism's ability to make a seal between the two spacecraft during docking operations, so activities occurring later on in the day, including the transfer of ELC-4, may be delayed. This was primarily because of a mis-alignment between the docking systems of the shuttle and station due to gravitational effects. The entire delay took up approximately 40 minutes.

During ''Discovery'''s approach to the station earlier on today, the crew of Expedition 26 took pictures of the shuttle's underside from the station's windows in order to assist in analysis of the heat shield of the spacecraft.

NASA officials are debating whether or not to extend the mission an additional day for a photo shoot of the International Space Station, as it is currently host to six docked spacecraft from the United States, Russia, Europe, and Japan. A decision regarding this possibility is expected on Tuesday.

STS-133 is Space Shuttle ''Discovery'''s 39th and final scheduled mission into space and the program's 35th mission to the ISS, as well as the 133rd in the entire . There are two flights remaining before the retirement of the fleet that are still in planning:  and .