Astronaut Zhai Zhigang is assembling and testing the space suit in the orbital module.

Astronaut aboard the Shenzhou-7 spacecraft, China's third manned spaceship, began to unpack and assemble the indigenous Feitian extra-vehicular activity (EVA) suit at 10:20 a.m. Friday in preparation for the first spacewalk.

As of 11:51 a.m., the spaceship which blasted off at 9:10 p.m. Thursday at Jiuquan Satellite Launch Center in the northwestern Gansu Province, has made 11 orbits around the earth as scheduled.

Physical conditions of the three astronauts who are in duty shift, all stay normal.

Zhai Zhigang and Liu Boming took on assembling in the orbital module while Jing Haipeng stayed in the re-entry module to keep a eye on the vessel operation.

Feitian, which literally means flying the sky, has 10 layers and weighs about 120 kilograms. The domestically-made suit costs 30 million yuan (about 4.4 million U.S. dollars), and takes up to 15 hours for astronaut to assemble and put on.

According to Wu Bin, director of the astronaut training research institute under the China Astronaut Training Center, the astronauts have to unpack the suit which was fixed on the interior wall of the orbital module. The unpacking procedure can be broken down to 12 steps, of which every step will be implemented with the help of the pincers.

After assembling, the replaceable parts including the purifier, oxygen bottle, batteries and remote control instruments will be installed on the suit.

The astronaut will have to adjust the size of the suit and test its obturation and functions after donning the suit. The procedure will be aided by another astronaut to ensure everything goes well, Wu said.

Since the astronaut will grew "fatter" after putting on the bulky suit, the re-entry module is built with an enlarged door of 850-millimeter-diameter, deputy chief designer of the spacecraft system Qi Yufeng told Xinhua.

A commander-in-chief post was for first time set up in the Shenzhou-7, which will be assigned to the No.1 astronaut, who will walk into the space. He will be assisted during Saturday's spacewalk by the No. 2 astronaut, who will stay in the orbital module during the process. The No. 3 astronaut will stay in the re-entry module.