In response, the Xi'an Aerospace Propulsion Institute said the document exaggerated the significance and influence Zhang had in the research project, in order to bring him back as soon as possible.

Online users have voiced concerns over the poor payment some important scientists get at State-run research institutes.

"An engineer who has influence on the fate of the country earns only 120,000 yuan a year, while a popular entertainer can rake in 800,000 yuan in a single episode of entertainment TV program. How sad it is!" a netizen with the screen name flower9292 said on social media platform Weibo.

"Scientists should be respected by our society," another web user said.

According to a survey published in Modern Science magazine in April, the brain drain problem at China Aerospace Science and Technology Corporation, a major contractor for the country's space program, has worsened in recent years.

The survey, which polled staffers at several major subsidiaries of the CASC, shows a growing trend of talent outflow from 2012 to 2016.

For example, Shanghai Academy of Spaceflight Technology, an institute under the CASC, has seen 428 employees quit in 2016, much higher than the 300 in 2012.

The survey shows 85 percent of job-hoppers were under 35, and essential technicians at their institutes.

Low payment is believed to be one major factor behind for the exodus toward private employers, per a report at ScienceNet.com, the online media platform of China Science Daily.