Goldman Sachs analyst Noah Poponak initiated coverage of Virgin Galactic with a Neutral rating and $19 price target. The stock closed Thursday up 29c to $20.73. The company’s long-term upside potential “could be substantial” if it can capture the space travel and supersonic flight opportunity, Poponak tells investors in a research note. However, the time to realization of the opportunity is “very long” and customer adoption and recurrence is uncertain, adds the analyst. Further, Poponak believes competition potential for Virgin Galactic is “not insignificant.”