Dec 12 (Reuters) - SpaceX has authorized an insider share sale that values Elon Musk's company at about $800 billion as the rocket-maker ​prepares for its initial public offering, Bloomberg News reported on ‌Friday. The company's move towards a public listing, which could rank among the largest global ‌IPOs, has been largely driven by the rapid expansion of its Starlink satellite internet business, including plans for direct-to-mobile service and progress in its Starship rocket program for moon and Mars m ...