SEOUL - South Korea suspended its third attempt to send a satellite into orbit by at least three days Friday, after a helium leak was detected in the rocket just hours before scheduled launch time. With only a five-day launch window that ends October 30, any further delay could result in a much lengthier postponement, officials at the Naro Space Centre told reporters. After two previous failures in 2009 and 2010, the current launch is considered critical for South Korea’s efforts to join an elite space club that includes Asian powers China, Japan and India. The 140-tonne Korea Space Launch Vehicle (KSLV-I) had been scheduled to blast off from the Naro site on the south coast on Friday afternoon.