San Francisco, May 17 (IANS) Elon Musk's company SpaceX has once again postponed the launch of the Falcon 9 rocket carrying the first 60 Starlink Internet communications satellites, this time owing to a "software issue".Just two hours prior to the opening of launch window late Thursday, the company cancelled the launch, second time in two days."Standing down to update satellite software and triple-check everything again. Always want to do everything we can on the ground to maximise mission success, next launch opportunity in about a week," SpaceX tweeted.With a mass of 18.5 tonne, the launch is the company's heaviest to date for either the Falcon 9 or Falcon Heavy rocket. The rocket will boost 60 Starlink satellites, each weighing 227kg, to an altitude of 440km, reports arstechnica.comSpaceX on Wednesday postponed the launch of the Falcon 9 rocket due to high winds.The launch will also feature a landing attempt by the Falcon 9's first stage on one of SpaceX's drone ships in the Atlantic Ocean, reports Space.com.Starlink is designed to provide high-speed Internet access to areas of the planet where broadband is rare, spotty or non-existent.SpaceX's ultimate goal is to put nearly 11,000 Starlink satellites in low Earth orbit between now and the mid-2020s,The company is one of several, including Jeff Bezos' Amazon, which are building these so called "constellations" of interconnected satellites to beam high-speed Internet from space. --IANS na/in