Missing a flight in a dream typically reflects the fear of a chance slipping past you while you're still getting ready for it -- feeling one step behind a deadline, a decision, or a version of your life you thought you'd have reached by now. The frantic run through the terminal is usually the real feeling on display.
When the three superiour planets shall be conjoined in regal signs, it is termed a great conjunction; and when the Sun beholds them, they make most potent and flourishing kingdoms. - William Lilly (1602.-1681.)