Keeping weight down was key challenge

Compared with Shenzhou VI, Shenzhou VII has "brighter eyes", "fewer wings" and a "longer body", Qin Wenbo, deputy chief commander of the launch program of the manned spacecraft, told the Xinhua News Agency yesterday.

The "eyes" refer to the two cameras added to the orbital and service modules, which will be used to make live broadcasts of Zhai Zhigang's spacewalk.

"The cameras had to overcome the challenges of weight and quality," Qin said, adding that they have been designed to work under extreme temperatures and in a vacuum.