Astronomers will gather on Monday at the NASA Ames Research Center in Mountain View, California for a controversial conference on the Kepler space mission that had been threatened with a planned boycott. NASA averted the boycott of the international meeting by reversing an order to exclude Chinese participants from the event.

Scientists were dismayed in September when NASA refused to register half a dozen Chinese postdocs for the meeting. The agency cited a US law passed in 2011 that excluded citizens of China and certain other nations from visiting NASA’s facilities.

The Second Kepler Science Conference, to take place in Mountain View on 4–8 November, will focus on the achievements of the telescope, which has so far detected hundreds of planets orbiting other stars. But attendees had threatened to quit the conference after NASA refused entry for the six Chinese researchers. A Chinese government spokesperson reacted by warning that such meetings “should not be politicized”.

‘Negative impact’

Members of the conference’s organizing committee then wrote to NASA objecting to the “deplorable” bans. “Had we been aware of this possibility…alternative venues to NASA/Ames would have been pursued,” they wrote. “The policies that led to this exclusion have had a negative impact on open scientific enquiry.”

The ban was overturned by NASA administrator Charles Bolden after Frank Wolf, a Republican Congressman from Virginia, wrote to him saying that the legislation “places no restrictions on activities involving individual Chinese nationals unless those nationals are acting as official representatives of the Chinese government”. Wolf had played a major role in the original legislation cited by NASA to reject the Chinese participants. Bolden also said that the Ames administrators had “acted without consulting NASA HQ”.

Potential boycotters welcomed the reverse. “I’m so happy,” says Yale University astronomer Debra Fischer, who had threatened to pull her team from the conference after she learned that administrators had initially refused the application of her Chinese postdoc Ji Wang to attend the meeting. Another exoplanet expert who will now attend after threatening to boycott it is Geoffrey Marcy of the University of California, Berkeley.

• Kepler astronomer Alan Boss of the Carnegie Institution in Washington spoke to Physics World about exoplanets and Kepler’s role in their discovery. You can listen to that conversation in this audio clip: