Chinese react as they watch live TV coverage of the nation's first spacewalk on a screen in a street Saturday in Beijing. A Chinese astronaut on Saturday performed the nation's first-ever spacewalk, the latest milestone in an ambitious program that is increasingly rivaling the United States and Russia in its rapid expansion.

Chinese astronaut Zhai Zhigang walks outside the orbit module of the Shenzhou-7 spacecraft for a spacewalk on Saturday.

Beijing ? Chinese celebrated their nation’s first spacewalk Saturday, gathering at outdoor TV screens to cheer live video of the milestone for a program that has ambitions of building a space station and challenging the U.S. and Russia in offworld exploration.

Stoking national pride one month after the close of the Beijing Olympics, state television’s coverage reflected much of the glory onto president and Communist Party leader Hu Jintao, who was present at Thursday’s launch and watched the spacewalk at Beijing’s ground control center.

“Your success represents a new breakthrough in our manned space program,” Hu told the astronauts in a scripted exchange that was also broadcast live.

“The motherland and the people thank you,” said Hu, who is chairman of the powerful Communist Party and government military committees that oversee the space program.

The spacewalk was mainly aimed at testing China’s mastery of the technology. Mission commander Zhai Zhigang’s sole task was to retrieve a rack attached to the outside of the orbital module containing an experiment involving solid lubricants.

Tethered to handles attached to the Shenzhou 7 ship’s orbital module, Zhai remained outside for about 13 minutes before climbing back inside through the open hatch.

“Greetings to all the people of the nation and all the people of the world,” Zhai said into an external camera he floated halfway out of the open hatch.

Fellow astronaut Liu Boming also emerged briefly from the capsule to hand Zhai a Chinese flag. The third crew member, Jing Haipeng, monitored the ship from inside the re-entry module.

While successful, the spacewalk wasn’t without its anxious moments.

Zhai, a 41-year-old fighter pilot, appeared to struggle with the hatch and then a fire alarm was triggered in the orbiter as he began the spacewalk.

Wang Zhaoyao, deputy director of manned space flight, conceded the combined effects of weightlessness and depressurization on the hatch opening operation hadn’t been fully anticipated. He blamed a faulty sensor for the fire alarm.