According to the China Academy of Space Technology (CAST) presentation at the 2015 International Space Development Congress in Toronto, Canada, Chinese interest in space-based solar power began in the period 1990–1995. By 2011 there was a proposal for a national program, with advocates such as Pioneer Professor Wang Xiji stating in an article for the Ministry of Science and technology that "China had built up a solid industrial foundation, acquired sufficient technology and had enough money to carry out the most ambitious space project in history. Once completed, the solar station, with a capacity of 100MW, would span at least one square kilometre, dwarfing the International Space Station and becoming the biggest man-made object in space" and "warned that if it did not act quickly, China would let other countries, in particular the US and Japan, take the lead and occupy strategically important locations in space." Global Security cites a 2011-01 Journal of Rocket propulsion that articulates the need for 620+ launches of their Long March-9 (CZ-9) heavy-lift system for the construction of an orbital solar power plant with 10,000 MW capacity massing 50,000 tonnes.