SpaceX has raised $2 billion in fresh capital at a valuation of about $45 billion, as the space company backed by Tesla's Elon Musk capitalized on strong investor interest after completing a significant milestone for NASA earlier this summer.

In a regulatory filing, the privately held company said it sold $1.9 billion in new shares in an offering that commenced on Aug. 4, with plans to sell an additional $165 million in equity and preferred stock in the weeks to come.

SpaceX Falcon 9 rocket launches from Kennedy Complex 39A.

Image source: SpaceX.

Terms of the deal were not disclosed in the filing, but Bloomberg reported last week that the offering would value SpaceX equity at close to $46 billion. By comparison, space-focused defense contractor Northrop Grumman is valued by the markets at $56 billion.

SpaceX has been on a roll of late. The company launched its first-ever crewed flight for NASA, the first astronaut launch from American soil since 2011, and earlier this month split a massive launch contract with the United Launch Alliance, a joint venture of Lockheed Martin and Boeing.

The company is also working to build out its Starlink satellite internet service and continues development toward Musk's eventual goal to transport people to Mars.

SpaceX officials have expressed little desire to go public, and as long as investors continue to have an appetite for its private offerings, there is no need for a company with such a long-range focus to go public and report quarterly results.

Investors could eventually have a chance to buy into Starlink, however, as some analysts have suggested SpaceX could eventually spin it off to help fund its other activities.