HOUSTON Space Shuttle Atlantis and its seven astronauts pulled off a high-flying docking with the International Space Station (ISS) early Sunday, setting the stage for a flurry of emergency repairs and a critical spacewalk later Sunday night.
With the shuttle and the station circling Earth at 17,500 m.p.h. (28,165 kilometers per hour), shuttle commander Jim Halsell gently linked the two spacecraft together at 12:31 a.m. Eastern Daylight Time (04:31 GMT) as they sailed about 209 miles (336 kilometers) above the eastern part of the Ukraine, near the border with Russia.
"We have capture," Halsell told mission controllers in Houston.
"Roger. Congratulations," replied capsule communicator Chris Hadfield.
As urgent as the mission is, Atlantis crew wont actually enter the station until Monday night.
First, astronauts Jim Voss and Jeff Williams are to make a six-and-a-half-hour spacewalk outside the ISS starting late Sunday. They will install construction equipment, replace a bad communications antenna and attach handrails on the station to help future spacewalkers.
Then the crew can open the hatch to the ISS and begin four days of hauling about a ton of supplies into the station including water, clothing and exercise gear for future resident crews and making needed repairs.
Lonely, sinking station
No humans have been aboard the ISS since almost a year ago, when shuttle Discovery docked on May 27, 1999, on a supply mission. That was NASAs first shuttle visit to the embryonic ISS, the first two pieces of which were joined in orbit in December 1998.
Before Atlantis undocks with the ISS late Friday afternoon, the shuttle will nudge the station about 26 miles (42 kilometers) higher in its orbit. Increased solar activity has caused Earths atmosphere to bulge outward, creating an atmospheric drag that has pulled the station closer to the planet by about 1.5 miles (2.4 kilometers) per week.
Atlantis astronauts will replace four ailing batteries to restore the ISS to full electrical power and prepare it for its next station piece the Russian-built service module or Zvezda ("Star") that is to be launched atop a Russian rocket in July and be docked by remote control.
Atlantis crew also will install fans to better circulate the air supply inside the station and insulation to make it quieter and more livable.
'Tally ho, the station'
The shuttle pulled in to the orbital outpost after a flawless rendezvous that began late Saturday with an intricate series of engine firings and steering maneuvers by Halsell and the rest of the crew.
They had been chasing the ISS since the shuttle was launched early Friday.
"Tally ho, the station," Halsell radioed on Sunday, as he spotted the station gleaming like a tiny star 39 miles (63 kilometers) ahead.
When the shuttle was about 600 feet (182 meters) behind and below the station, Halsell moved from his cockpit seat to another set of controls at the rear of Atlantis cabin.
From there, he could look out the overhead window to see the 76-foot- (23-meter-) long station floating above him. The ISS was oriented so that one end was pointed toward deep space and the other faced Earth.
Help from laser range finders
While Halsell was busy flying, pilot Scott "Doc" Horowitz kept tabs on the rest of the shuttles systems. Others in the crew used a variety of hand-held laser range finders and laptop computers to keep track of the closing distance.
Halsell eased Atlantis until it was 500 feet (152 meters) away from the stations lower end and then flew the shuttle in front of and around the station until Atlantis reached a point about 300 feet (91 meters) above it.
"Its looking real nice," Horowitz said, as the station grew into view with Earth in the background.
"That is a beautiful sight," replied Mission Controls Hadfield, watching TV video beamed from Atlantis.
Halsell then gradually eased the shuttle downward, stopping briefly at 170 feet (52 meters) and again at 30 feet (9 meters) from the station. That allowed Russian ground controllers to make sure the station remained motionless in space.
Finally, Halsell slowly brought Atlantis onto the stations docking port at a glacial speed of just a tenth of a foot per second.
The docking was right on time and unfolded without a hitch due to intensive ground training and planning, said Phil Engelauf, lead flight director. He made his comments at a briefing a couple hours after the docking.
"Its hard to make it look any easier than the crew made it look," Engelauf said. "It was really a textbook rendezvousand the procedure was virtually flawless."
Halsell "flew right by the book," Engelauf said. "It was like watching a ballet."
Spacewalk late Sunday
With the two spacecraft firmly mated, the next critical operation will begin at 10:31 p.m. EDT Sunday (Monday, 02:31 GMT) when astronauts Williams and Voss start their 6-and-a-half-hour spacewalk.
The two will secure a wobbly U.S. robot construction crane, finish assembling a similar Russian crane, replace a faulty communications antenna and install eight handrails for future spacewalkers
Voss and two of his Atlantis crew mates -- Susan Helms and Russian cosmonaut Yuri Usachev are scheduled to take up residence aboard the ISS next year as the second international live-aboard crew.
The stations first resident crew composed of one American and two Russians is to arrive in November aboard a Russian Soyuz rocket.
Said Voss: "This is the best training we could ever possibly do."
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