The mainland has built a prototype probe for its much-delayed space telescope programme and scheduled the launch for 2011, China Central Television reported. Astronomers say the Hard X-ray Modulation Telescope will study supernovas and black holes. A physicist involved in the programme said technology once believed to be a joke would be used on the telescope. 'We proposed the technology in the early 1990s,' said the professor. 'Some experts in developed countries laughed at it. Their opinions reached the ... mainland, and the programme was postponed. Now that the European Space Agency has included the method in its textbook, the mainland authorities have finally given us a go. But it is too late. Integral, the European hard X-ray telescope, has already made a lot of groundbreaking discoveries.' A black hole does not emit X-rays. With huge gravity, it attracts an enormous amount of matter, forming several layers of rings. Each ring emits different radio signals. The innermost ring is believed to emit hard X-rays, the high-energy portion of the electromagnetic spectrum. More than 30 satellites capable of detecting X-rays have been launched worldwide. Currently operating are Chandra and Swift, both from Nasa. Li Xiangdong, an astronomer at Nanjing University, said that the launch of the probe would boost his research. 'To astronomers, each second the telescope spends watching the universe is a precious asset,' he said. 'Chandra, for example, has given access priority to American scientists. Astronomers from other countries, especially those who do not have their own telescopes, will have to compete fiercely for a few moments that the Americans spare.'