Lockheed Martin could play a large role in helping smaller space companies to IPO.Valued at $110 billion and doing nearly $70 billion in annual business, Lockheed Martin (LMT -0.05%) is the world's biggest defense company. It's also a major player in space.Lockheed Martin builds the Orion spacecraft that will one day carry NASA astronauts (back) to the moon, making it an integral part of NASA's Project Artemis. Lockheed owns half of United Launch Alliance, still the preferred provider of satellite launches ...