Rocket Lab stock costs a lot, and must execute perfectly to justify its current share price.Crystal balls are said to be useful items -- but very hard to come by for investors. For better or worse, investors in Rocket Lab (RKLB 3.79%) stock have something very close to a crystal ball: hard numbers, laid out by management and by Wall Street analysts, telling them where Rocket Lab stock will be in three years.Are you thinking about investing in America's second most prolific launcher of space rockets (after S ...