Space-transportation startup Rocket Lab USA Inc. is nearing a deal to go public through a merger with special purpose acquisition company Vector Acquisition Corp. (NASDAQ: VACQ), the Wall Street Journal reported Sunday, citing people familiar with the matter. What Happened: According to the WSJ report, the deal could value the small-satellite launch firm at about $4.1 billion, including debt, and could be finalized by Monday. The deal comes amid a wave of SPAC mergers on Wall Street in recent months. San Francisco, California-based Vector Acquisition raised $300 million through an initial public offering in September last year.