A Russian Soyuz spacecraft carrying two cosmonauts and a NASA astronaut glided to a smooth linkup with the International Space Station Thursday, two days after a technical snag blocked a fast-track rendezvous and docking shortly after launch Tuesday.

Astronaut Rick Mastracchio posted this view of the approaching Soyuz from the International Space Station. Photo credit: NASA/Rick Mastracchio With commander Alexander Skvortsov monitoring the automated approach from the Soyuz's center seat, the docking mechanism in the nose of the Soyuz TMA-12M ferry craft engaged its counterpart at the end of the upper Poisk module at 7:53 p.m. EDT (GMT-4) as the two spacecraft sailed 252 miles above southern Brazil.

"Sasha, congratulations to you and your crew on having successfully completed the first part of your mission," radioed Oleg Ostapenko, director of Roscosmos, the Russian federal space agency. "Congratulations to everyone."

"Thank you, sir." Skvortsov replied.

A few moments later, latches engaged to firmly lock the Soyuz in place. After extensive leak checks, Skvortsov, flight engineer Oleg Artemyev and NASA astronaut Steven Swanson were expected to float into the station, welcomed aboard by Expedition 39 commander Koichi Wakata, Mikhail Tyurin and Rick Mastracchio.

All six crew members planned to gather in the Zvezda command module for a traditional post-docking radio chat with space agency managers, friends and family members gathered at the Russian flight control center near Moscow.

After a safety briefing, Skvortsov, Artemyev and Swanson planned to settle in, looking forward to a bit of time off after a busy, unexpected two-day rendezvous. U.S. flight controllers, meanwhile, planned to press ahead with work to load new software into the station's computer system.

The station crew originally expected to take delivery of a commercial SpaceX cargo ship next Wednesday, but the launching, planned for Sunday, was put on hold because of presumed problems with U.S. Air Force tracking equipment. A new launch date has not yet been announced.

Skvortsov, Artemyev and Swanson blasted off from the Baikonur Cosmodrome in Kazakhstan on Tuesday. Shortly after reaching orbit, the spacecraft's computer began executing a planned six-hour, four-orbit rendezvous, a procedure requiring a series of carefully timed rocket firings to home in on the space station.

The first two rocket firings went smoothly, but the spacecraft was slightly out of attitude, or orientation, for the third "burn" and the rendezvous procedure was aborted.

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Soyuz docks with International Space Station