For a decade, Eric Schmidt ran Google as chief executive and as the “adult” in the room, mentoring the internet company’s young founders, Larry Page and Sergey Brin. In 2011, Mr. Schmidt handed control of Google back to Mr. Page. He has not taken another C.E.O. job since.
But on Monday, Mr. Schmidt told employees of Relativity Space, a rocket start-up in Long Beach, Calif., that he had made a significant investment and taken a controlling stake in the company, and would take over as chief executive, two people with knowledge of the meeting said.
Mr. Schmidt, 69, succeeds Relativity Space’s current chief and co-founder, Timothy Ellis, the two people said. It is unclear how much money Mr. Schmidt has invested in the start-up.
Relativity Space is one of a crop of start-ups angling to manufacture rockets that can carry smaller payloads of around two tons or less, up to low to medium Earth orbit. Some of these companies focus on building cheaper, reusable rockets to launch commercial payloads — usually satellites — into space for a fraction of the cost of legacy manufacturers that use pricier, disposable rockets.
The aim would partly be to take on Elon Musk’s SpaceX, the dominant rocket maker. Relativity Space has also said it has a long-term goal of creating an industrial base on Mars.
Mr. Ellis, who once worked at Jeff Bezos’ rocket company, Blue Origin, founded Relativity Space in 2016 with a former SpaceX employee, Jordan Noone, on the premise that more could be done to bring down the costs of building rockets, using technologies like 3-D printers, automated robotics and artificial intelligence.
The company has raised close to $2 billion at an estimated valuation of $4 billion to $6 billion from investors such as Coatue, BlackRock, Bond, Fidelity and Mark Cuban, among others, according to data compiled by PitchBook.
In recent years, Relativity Space has run into challenges. It launched its small Terran 1 rocket once, in 2023, and it failed soon after liftoff. A month later, Relativity Space announced it would retire Terran 1 to focus on the Terran R, a larger rocket that would compete with SpaceX’s Falcon 9 and Falcon Heavy. The start-up has moved away from focusing entirely on 3-D printed materials and has begun incorporating more traditionally made parts in building its rockets.
At the same time, Relativity Space faces stiff competition. The company, which has said it plans to launch the Terran R in 2026, could by then face many rivals including the New Glenn, the orbital rocket from Blue Origin; Vulcan by United Launch Alliance; Neutron by Rocket Lab; and the Medium Launch Vehicle by Firefly Aerospace, a Texas start-up that landed a spacecraft on the moon last week.
By late last year, Relativity Space faced difficulties raising new funding, according to the two people with knowledge of the matter.
Mr. Schmidt, who holds a pilot’s license and has personal investments in the aerospace and defense industries, including drone research and A.I., grew interested in Relativity Space in 2024, they said.
This year, he agreed to invest in the company through Hillspire, his family office investment firm, and continue supporting Relativity Space on the condition that he would take over day-to-day operations, the people said. Bloomberg reported Mr. Schmidt had invested in Relativity Space in January.
Mr. Schmidt will focus on building up operations and improving product and manufacturing execution, the people said. In Monday’s meeting with employees, he expressed his passion for the project, they said.
Despite the struggles, Relativity Space executives have expressed confidence in the company’s progress. The start-up has noted milestones from its Terran 1 rocket, such as how it was the first time a 3-D printed rocket had reached “max-q,” which is the point when the vehicle experiences the strongest stresses. Terran 1 also achieved stage separation, when the booster used for liftoff drops from the vehicle’s second stage.
It’s unclear how consequential these are, since the company has decided to move away from 3-D printed materials, which will ultimately raise the cost of building rockets higher than previously expected.
After the Terran 1 launch, Relativity Space reached close to $3 billion in future launch contracts with customers, the two people familiar with the company said.
In 2022, before the Terran 1 failure, Relativity Space, collaborating with another start-up named Impulse Space, announced an audacious plan to send the first private space mission to Mars.
At the time, Mr. Ellis acknowledged the plan was “at the edge of crazy.” He added that the mission, launching on a Terran R, could be ready in two and a half years, when Mars and Earth were properly lined up. That window, in late 2024, passed.