At 63, Chang is the CMC's second-youngest member, meaning he would probably serve at least one five-year term.

As director of the People's Liberation Army's General Armaments Department overseeing missile development, the Henan native can claim responsibility for several key achievements, including the successful Shenzhou-IX spacecraft docking in June.

Past practice also favours Chang's promotion. He is the most senior leadership candidate from the military's ground forces, which have traditionally held sway on the commission.

Appointees to the two professional vice-chairmanships have usually been selected from within the CMC.

Chang's mentor, Guo Boxiong, is currently a vice-chairman of the CMC. And perhaps most importantly, Chang appears to have the blessing of President Hu Jintao, who is also the CMC chairman.

Within the commission Chang would answer only to Xi Jinping, who is currently a commission vice-chairman and is set to succeed Hu.

A CMC vice-chairmanship carries political influence as well as military power, since past vice-chairmen have also received places on the elite Politburo.

Chang, however, is not entirely without competition for the top CMC job. General Xu Qilang, the 62-year-old air force chief and a CMC member, will almost certainly remain on the commission and secure a vice-chairmanship.

PLA Navy chief Admiral Wu Shengli, 67, also an incumbent CMC member, could also stay on the panel for another term, provided he gets a promotion. Wu is strongly tipped to replace outgoing General Liang Guanglie as Minister of Defence, meaning he will stay put as a CMC member.

Potential candidates for another vice-chairmanship include General Fan Changlong , 65, commander of the Jinan military area command, and General Liu Yuan, 61, the political commissar of the General Logistics Department.

Their selection is considered less likely because they lack experience on the CMC.

Like his mentor Guo, Chang is considered a heavyweight of the PLA's "northwest army". Both generals spent more than three decades in the Lanzhou military area command, including stints in command of the 47th Army Corps based in Lingtong, Shaanxi province.

Apart from Guo and Chang, General Fang Fenghui, commander of the Beijing military area command, and Lieutenant General Xu Fenlin, commander of the Guangzhou military area command, are also considered key members of the "northwest army".

It said that according to his childhood friend Chen Lianjun, he was born into a poor family, the son of a carpenter, and had four siblings.

Chen said that thanks to his strong build and height, Chang was hand-picked by conscription officials when they watched his powerful performance in a basketball game during a recruitment trip to Nanyang in February 1968. Chen added: "Chang is a nostalgic, amiable and easy-going person who cherishes past times and old acquaintances."

Chang joined the Lanzhou command later in 1968 and quickly gained the favour of his superiors.

He was appointed personal secretary to Han Xianchu, the general who oversaw the region from 1973 to 1980.

In late 2004, Chang was serving as chief of staff in the Beijing military area command when Hu - then just settling into the role of CMC chairman - promoted him to lead the Shenyang military area command.

His northeastern posting coincided with Vice-Premier Li Keqiang's own appointment as party secretary of Liaoning province.

At the time, Hu was believed to be grooming his protégé Li to be his successor and the move was seen as an effort to build a bond between the two men.

It was also an indication that Hu saw Chang as a contender for top military office.

Hu removed any doubt three years later, when he selected Chang over General Ge Zhengfeng, then first chief of general staff and a key member of the rival "northeast army", to become director the PLA's General Armaments Department.

With that came Chang's promotion to his current seat on the CMC and the rank of full general.

As chief of the General Armaments Department, Chang oversees the development of new strategic missiles and also the country's manned spaceflight programme.

In that role, Chang supervised the successful mission to send China's first woman astronaut, Major Liu Yang, into space to dock the Shenzhou-IX spacecraft with the experimental Tiangong-1 space station. The DF-31A intercontinental ballistic missile has also been deployed during his tenure.

During his time in Shenyang, Chang was lauded for establishing an effective emergency response system along the North Korean border after responsibility for frontier defence was shifted from the Public Security Ministry to the PLA.

Antony Wong Dong, of the Macau-based International Military Association, praised Chang as an all-round military professional, citing in particular his leadership of the space programme.

"Taking these contributions and achievements into account, Chang is more than qualified for a vice-chairmanship in the new CMC," Wong said.

Nonetheless, rumours have continued to circulate that Chang could be passed over.

Some believe he has somehow been implicated in the corruption probe earlier this year into Gu Junshan, the former deputy director of the General Logistics Department, although Chang's name has not appeared in any official report.

Also working against him could be a desire to maintain a balance between the powerful northeast and northwest armies. While current CMC vice-chairman Guo comes from the northwestern region, his colleague Xu Caihou, another CMC vice-chairman, comes from the northeast.

Because of this, some say Fan Changlong, the Jinan commander, could emerge as a dark horse.

He is from the northeast army and is also a protégé of Xu.

But if Chang fails to land the vice-chairmanship, he may end up with a nice consolation prize - the post of minister of defence.