Aug 23 (Reuters) - Virgin Orbit, the small satellite launch service which is a part of billionaire Richard Branson’s conglomerate, said on Monday it is going public through a merger with a blank-check vehicle in a deal that values it at $3.2 billion. (Reporting by Niket Nishant in Bengaluru; Editing by Shailesh Kuber) Our Standards: The Thomson Reuters Trust Principles.