The so-far unsuccessful Russian Mars mission - with a Chinese satellite aboard - may instead boost China's own probe of the Red Planet. 

Phobos-Grunt, which is carrying China's first interplanetary satellite Yinghuo-1, was still stranded in its Earth orbit on Friday, after the latest efforts to establish contact with the spacecraft failed. 

"It's both regretful and disappointing," said Jiao Weixin, an Earth and space scientist with Peking University. "But the event will help accelerate the country's efforts to carry out deep space exploration independently." 

Russian news agency Ria Novosti said that attempts to receive a signal from the unmanned Phobos-Grunt had failed on Friday, three days after it blasted off from Baikonur in Kazakhstan. It soon encountered engine failure. 

"The data from Yinghuo-1 could have been useful for China's Mars mission," said Jiao, who is also deputy chief of the space exploration committee under the Chinese Society of Space Research. 

"But even if it were a success, you can't expect much from the orbiter, which has a very light payload and whose data transmission relies on Russia," he said. 

Designed with a two-year lifespan to discover why water disappeared from Mars and to explain other environmental changes on the planet, the Chinese probe weighs only 115 kg, he said. 

Jiao said Chinese scientists had hammered out a program for Mars exploration, but it is still awaiting central government approval. 

"Under a 2007 project of the Ministry of Science and Technology, scientists have worked out objectives, exploration procedures and studied the key technology needed for a Mars mission," he told China Daily. 

For the country to carry out Mars exploration, it must deploy a track and control network for deep space, in addition to developing more powerful rockets, Jiao said. 

Pang Zhihao, deputy editor-in-chief of the monthly publication Space International, said China is building its deep space network, an infrastructure necessary for controlling probes to explore planets in deep space, and this joint Mars exploration counts on Russian ground control. 

China's deep space network is slated to be completed by 2016, as two domestic ground stations will be finished by 2012 and a third in South America will be done by 2016, according to earlier reports. 

Ye Peijian, chief designer of the nation's first moon probe, said the two domestic ground stations will enable scientists to track and control a Mars probe. 

The distance between Earth and the Red Planet varies from 55 million km to about 350 million km depending on the orbit of the two planets around the sun. 

On the third day since the launch of Phobos-Grunt, officials with China's space agency still declined to comment. 

Observers said that China could do nothing to help in the ongoing salvage efforts but wait for news from Russia. 

They also said that insurance could be a concern if the mission was a total failure. 

On Friday, Russia's Interfax news agency quoted an unidentified source in the Russian space sector as saying: "The probability of saving the probe is very, very small." 

Vladimir Popovkin, head of Russia's space agency Roscosmos, said that engineers had two weeks to restart the probe's booster before its batteries ran out.