WASHINGTON (Reuters) - The prospects for cooperation between the United States and China in space are fading even as proponents say working together in the heavens could help build bridges in often-testy relations on Earth.

The idea of joint ventures in space, including spacewalks, explorations and symbolic “feel good” projects, have been floated from time to time by leaders on both sides.

Efforts have gone nowhere over the past decade, swamped by economic, diplomatic and security tensions, despite a 2009 attempt by President Barack Obama and his Chinese counterpart, Hu Jintao, to kick-start the bureaucracies.

U.S. domestic politics make the issue unlikely to advance when Obama hosts Hu at the White House on January 19.

Washington is at odds with Beijing over its currency policies and huge trade surplus but needs China’s help to deter North Korea and Iran’s nuclear ambitions and advance global climate and trade talks, among other matters.

Hu’s state visit will highlight the importance of expanding cooperation on “bilateral, regional and global issues,” the White House said.

But space appears to be a frontier too far for now, partly due to U.S. fears of an inadvertent technology transfer. China may no longer be much interested in any event, reckoning it does not need U.S. expertise for its space program.

New obstacles to cooperation have come from the Republicans capturing control of the U.S. House of Representatives in the November 2 congressional elections from Obama’s Democrats.

Representative Frank Wolf, for instance, is set to take over as chairman of the appropriations subcommittee that funds the U.S. space agency in the House.

A China critic and human rights firebrand, the Republican congressman has faulted NASA’s chief for meeting leaders of China’s Manned Space Engineering Office in October.

“As you know, we have serious concerns about the nature and goals of China’s space program and strongly oppose any cooperation between NASA and China,” Wolf and three fellow Republicans wrote NASA Administrator Charles Bolden on October 15 as he left for China.

SPACE EXPLORATION

Obama and Hu, in a statement in November 2009, called for “the initiation of a joint dialogue on human spaceflight and space exploration, based on the principles of transparency, reciprocity and mutual benefit.”

The statement, marking a visit by Obama to China, also called for reciprocal visits in 2010 of NASA’s chief and “the appropriate Chinese counterpart.”

Bolden, who went to China as head of a small team, said discussions there “did not include consideration of any specific proposals for future cooperation” -- a statement apparently designed to placate Wolf, who will have a big say in NASA’s budget.

The Chinese visit to NASA did not materialize in 2010 for reasons that have not been explained. NASA representatives did not reply to questions but a Chinese embassy spokesman, Wang Baodong, said he suspected it was “mainly a scheduling issue.”

China is an emerging space power. Over 13 years starting in August 1996, it ran up 75 consecutive successful Long March rocket launches after overcoming technical glitches with the help of U.S. companies.

China launched its second moon orbiter in October. In 2008, it became the third country after the United States and Russia to send astronauts on a spacewalk outside an orbiting craft.

Beijing plans an unmanned moon landing and deployment of a moon rover in 2012 and the retrieval of lunar soil and stone samples around 2017. Chinese scientists have talked about the possibility of sending a man to the moon after 2020 -- more than 50 years after U.S. astronauts accomplished the feat.

ANTI-SATELLITE TESTS

Possible U.S.-Chinese cooperation became more controversial after Beijing carried out a watershed anti-satellite test in January 2007, using a ground-based missile to knock out one of its inactive weather satellites in high polar orbit. No advance notice of the test was given.

Thirteen months later, the United States destroyed a malfunctioning U.S. spy satellite using a ship-launched Raytheon Co Standard Missile 3 after a high-profile buildup to the event. The U.S. interception was just outside the atmosphere so that debris would burn up promptly.

U.S. officials say China’s capabilities could threaten U.S. space assets in low orbit. The Chinese test also created a large cloud of orbital debris that may last for 100 years, boosting the risk to manned spaceflight and to hundreds of satellites belonging to more than two dozen countries.

China’s work on anti-satellite weapons is “destabilizing,” Wallace Gregson, assistant U.S. secretary of defense for Asian and Pacific security affairs, said in December, also citing its investment in anti-ship missiles, advanced submarines, surface-to-air missiles and computer warfare techniques.

“It has become increasingly evident that China is pursuing a long-term, comprehensive military buildup that could upend the regional security balance,” Gregson told a forum hosted by the Progressive Policy Institute in Washington.

The Heritage Foundation, a conservative think tank, called on members of the incoming Congress to be wary of any space cooperation with China on the grounds it could bolster Beijing’s knowledge and harm U.S. security.

“Congress should reject (the Obama) administration attempts to curry favor with the international community while placing U.S. advantages in space at risk,” Dean Cheng, a Heritage research fellow for Chinese political and security affairs, and two colleagues said in a December 15 memo to lawmakers.

Proponents of cooperation say even symbolic steps, such as hosting a Chinese astronaut on the International Space Station, might help win friends in Beijing and blunt hard-liners.

Gregory Kulacki, China project manager for the Union of Concerned Scientists, a group often at odds with U.S. policy, said cooperation would be more of a political project than a technical one.

“We need to get past the idea that the Chinese need us more than we need them,” he said.