PARIS — Search engine giant Google Inc. said it invested $900 million in SpaceX “to support continued innovation in areas of space transport, reusability and satellite manufacturing.”

In a Feb. 9 filing with the U.S. Securities and Exchange Commission, Mountain View, California-based Google confirmed what had been widely presumed — that it was responsible for the lion’s share of the recently announced billion-dollar investment in rocket builder SpaceX that included Fidelity Investments.

Hawthorne, California-based SpaceX, in addition to building and launching rockets, has announced plans to open a satellite manufacturing facility in Seattle whose most immediate task will be designing and building a constellation of Internet satellites in low Earth orbit.

SpaceX is also modifying its Falcon 9 launch system to return the first stage for reuse after each launch, a development SpaceX says could result in a material reduction in launch costs.

It is the Internet delivery satellite project that was presumed to have attracted the attention of Google, which is investing in a multitude of broadband platforms including terrestrial fiber and the Project Loon idea of providing Internet from stratospheric balloons.

Google’s 10-K filing in fact devotes more space to Loon than to SpaceX or to Google’s $478 million cash purchase of Skybox Imaging, a company launching a constellation of Earth imaging satellites.

“We expect the acquisition to keep Google Maps accurate with up-to-date imagery and, over time, improve Internet access and disaster relief,” Google said without specifying Skybox’s eventual Internet access role.

Google said $388 million of its Skybox purchase price was attributable to goodwill, “primarily attributable to the synergies expected to arise after the acquisition.”

The company said Project Loon goes to the core of Google’s mission of bringing Internet access to those who do not have it.

“We asked, what if we could use a network of balloons that could fly at the edge of space and provide connectivity in rural and remote areas?” Google said. “Loon has helped students in Brazil and farmers in New Zealand experience the power of an Internet connection for the first time. And as the program expands, we hope to bring this to more and more people — creating opportunities that simply did not exist before for millions of people, all around the globe.”

Peter B. de Selding was the Paris bureau chief for SpaceNews.