A 42-year-old Chinese military pilot will don a homemade spacesuit and step outside the Shenzhou 7 spacecraft early Saturday on the country's first spacewalk, making China the third nation to accomplish such a feat.

Chinese officials have not formally identified which member of the three-man crew will be tapped for the spacewalk, or extra-vehicular activity. Earlier reports indicated Zhai Zhigang, the mission commander, will take the historic step into space.

Zhai, Liu Boming and Jing Haipeng, all 42-year-old fighter pilots, were launched aboard the Shenzhou 7 spaceship at 1310 GMT (9:10 a.m. EDT) Thursday. The craft's engines fired about seven hours later to reach a circular orbit about 215 miles high.

The astronauts spent much of Friday unpacking and readying two spacesuits for the EVA. The lead spacewalker will exit the spacecraft wearing a Chinese Feitian spacesuit, which weighs 265 pounds on Earth and costs about $4.4 million, according to the state-run Xinhua news agency.

The Feitian and a Russian Orlan suit were fully assembled by about 1400 GMT (10 a.m. EDT) Friday, ending more than 11 hours of work by Zhai and Liu, Xinhua reported.

Engineers in mission control in Beijing helped guide the astronauts through the 12-step procedure, officials said.

The two spacewalkers spent more than one-and-a-half hours breathing pure oxygen later Friday to help adapt their bodies to the low-pressure environment inside the spacesuits. This process is similar to preparations before spacewalks in the U.S. and Russian space programs.

The spacewalk, slated to last about 30 minutes, will begin at about 0830 GMT (4:30 a.m. EDT), or Saturday afternoon in China. Experts said the lead spacewalker, likely Zhai, will spend about 20 minutes actually floating outside the spacecraft's hatch.

Zhai will retrieve an experiment mounted to Shenzhou 7's exterior during the spacewalk.

Another astronaut, reportedly Liu Boming, will stay inside the orbital module at the forward end of the ship. Liu will be in an Orlan spacesuit that China acquired from Russia, ready to assist Zhai if something goes wrong.

The Feitian and Orlan suits have similar appearances, and China purchased three space-rated Orlan suits from Russia in 2004, according to Wang Zhaoyao, deputy director of China's manned space program.

The orbital module will act as an airlock during the spacewalk, depressurizing and pressurizing the cabin before and after the EVA.

Jing will stay behind in the pressurized entry capsule to monitor the ship's systems.

The crew trained in giant pools to prepare for the spacewalk. Water is the best way to simulate weightlessness and is used to train Russian and U.S. astronauts.

China Central Television will provide live coverage of the spacewalk on their Chinese and English language channels, the state-run television network announced Friday.

Saturday's breakthrough will make China the third nation to complete a spacewalk after the former Soviet Union and the United States. Those countries' first spacewalks both occurred in 1965.

First came the Soviet Union. Cosmonaut Alexei Leonov floated through the hatch of the Voskhod 2 spacecraft on March 18, 1965, in a harrowing 12-minute spacewalk that was not announced until after it was completed.

Leonov's bulky spacesuit made it difficult for him to move, and the cord linking him with the spacecraft became twisted. After Leonov struggled to enter the airlock, he was forced to manually lower pressure inside his spacesuit, which had ballooned larger than its normal size.

Leonov finally closed the hatch and pressurized the airlock to end the first spacewalk in history.

Astronaut Ed White completed the first U.S. spacewalk less than three months later on June 3, 1965. White's 23-minute excursion outside the Gemini 4 went more smoothly than the Russian spacewalk.

White used a handheld gun-like thruster fueled by oxygen gas to help maneuver around the exterior of the two-man capsule.