The next time humans set foot on the moon, they may well plant a five-starred red flag there. The Chinese space program is developing rapidly, and further progress should come this year when taikonauts, a colloquial term for Chinese astronauts, visit the Tiangong-1 space module.

The president’s chief science adviser John Holdren has said the U.S. would benefit from cooperation with China. The two countries could tackle the problem of space debris and, possibly, lay groundwork for a joint mission to Mars. His thinking fits with the Obama administration’s so-called Asian pivot, a shift in focus from the Middle East to China’s growing influence; the idea is that science and technology cooperation could be a useful lever in negotiations.

But federal legislation now prohibits NASA from pursuing any such joint efforts. The relevant clause first popped up last April in a stopgap funding bill, and in November it reappeared in the legislation funding NASA for 2012. The author of the provision is Representative Frank Wolf of Virginia, who cites China’s human-rights record and the threat of espionage. The “Wolf clause” has already had a visible effect: journalists from the state-owned Xinhua News Agency were barred from a shuttle launch last year.

One widely held concern is just who would be on the Chinese end of a hypothetical manned mission with the U.S. It is clear that the People’s Liberation Army plays a major role in China’s space missions, says Dean Cheng, a research fellow at the Heritage Foundation in Washington, D.C. “It begs the question of whether there is a civilian manned space program in any meaningful sense of the word,” he says.

Many believe that limited collaboration, such as on unmanned missions, would be constructive. “We found ways to cooperate with the Soviet Union during the cold war,” says Scott Pace, director of the Space Policy Institute at George Washington University. “I don’t see why we couldn’t do similar types of things with China.”

So the White House is pushing back, trading legal memos with congressional investigators on the constitutionality of the Wolf clause, which also binds Holdren’s Office of Science and Technology Policy. Although a court battle seems unlikely, a spokesperson says that Wolf plans to keep a close eye on Holdren and his colleagues in the coming year and “hold their feet to the fire” to ensure compliance.