Story highlights Chinese spacecraft makes first manual docking

On same day, deep-sea dive record is set by manned sub

Both feats seen as source of pride for China as leaders seek to bolster support

From earthly orbit to the deepest reaches of the Pacific Ocean, China has notched up two more firsts for the country's ambitious sea and space exploration programs.

On Sunday, the three Chinese astronauts on board the Shenzhou-9 manually docked their spacecraft to the Tiangong 1, an orbiting space lab.

On the same day, a Chinese manned submersible vehicle set a deep-diving record when it descended 7,020 meters into the Mariana Trench in the Pacific Ocean.

The three men on board the sub -- dubbed oceanauts in China -- sent greetings to the three astronauts on the Shenzhou-9 spacecraft.

"We wish for a great success of the manual docking and brilliant achievements in China's manned space and manned deep-sea dive causes," Xinhua quoted Ye Cong, Li Kaizhou and Yang Bo as saying.

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Both endeavors have been a source of pride for China and could help bolster support for the Chinese Communist Party as it undergoes a once-in-a-decade leadership transition later this year and handles the fall-out from the demise of former politician Bo Xilai.

"Scientific achievements like this allow the Party to again remind the population of what has been achieved under their leadership," said Dean Cheng, a research follow at The Heritage Foundation in Washington.

"It buys credibility and justification for their continued rule, even as scandals like Bo Xilai eat away at their authority.

"I would expect additional such displays in the coming months, especially if reports of a troubled succession are correct."

Mastering the technique of joining spacecraft together manually is also seen as an essential step toward China's goal of building a space station in 2020.

Local media reported that China also plans to start building a deep-sea station to accompany its march into space.

The three-man sub Jiaolong, named after a mythical sea dragon, worked for three hours on the sea floor, collecting water samples, sediments and placing markers at the bottom of the sea.

Xinhua said the 11-hour dive "enabled China to join the ranks of deep-sea faring countries" like the US, Japan, France and Russia.

Cheng said that the ability to undertake such deep-sea dives also had commercial applications and would help China drill for oil and undertake deep-sea mining.

China has been funding oceanographic research for more than a decade after it was added to the country's 9th Five Year Plan in 1996, he added.

Meanwhile, a spokeswoman for China's manned space missions said the program, which began in 1992, would cost a total of almost 40 billion yuan (US$6.27 billion).

"These programs are emblematic of sustained Chinese investments in the human capital and infrastructure of science," said Cheng.

"This should be a warning call to the U.S. and Western Europe that their traditional dominance in science is in jeopardy."

But some Chinese internet users, while lauding the achievements, questioned whether these exploits were the wisest use of China's new-found wealth.

"Diving into the sea and flying out to space. China now can do them both," said one user of the Twitter-like portal Sina Weibo.

"It marks the development of technology and we are proud of it. But can the government care more about its people's well-being too?"