Elon Musk's rocket company had a near-flawless market debut.TIMOTHY A. CLARY / AFP via Getty ImagesSpaceX stock declined sharply on Monday, its third consecutive trading day of losses.SpaceX's rally last week briefly valued the company at nearly $3 trillion, surpassing Amazon.The rocket company is also selling bonds to repay loans, it said in a Monday filing.First, they had lift-off; now, they're coming back to Earth with a bump.SpaceX shares dr…