The subject line of the email was 'Space is Sexy 3D Printing an Entire Rocket.' Two young engineers sent it cold to Mark Cuban, offering him a fifth of a $500,000 seed round. Cuban replied. (Accounts differ on the exact terms.)
Tim Ellis, reportedly raised in Plano, Texas, was the eldest of three children. A Los Angeles Times piece described a boyhood obsession with Lego: he threw away the printed instructions from the roughly 200 sets he begged his parents for, preferring to build his own sleek spaceships.
Tim Ellis, reportedly raised in Plano, Texas, was the eldest of three children.
He went to USC, began as an undecided major, and ended with a bachelor's and a master's in aerospace engineering, plus a leadership role in the university's Rocket Propulsion Lab alongside classmate Jordan Noone. Then came Blue Origin, where he worked on bringing metal 3D printing in-house. He was surprised, he reportedly said, how little interest others showed. He raised the idea with Jeff Bezos, who agreed it was promising but not enough to act on. Ellis decided to start his own company.
Founded in 2015, Relativity grew on a bold claim: print most of the rocket. The money followed. A $500 million round in 2020 valued it at $2.3 billion, and in June 2021 Fidelity led $650 million at $4.2 billion, bringing the total to $1.335 billion.
Then the hard part. On March 23, 2023, Terran 1 flew for the first time, called 'Good Luck, Have Fun.' It survived max-q, the point of greatest stress, but suffered an upper-stage anomaly and did not reach orbit. A month later the company retired Terran 1 to focus on the larger, partially reusable Terran R.
In March 2025 came the sharper turn: Eric Schmidt replaced Ellis as CEO and took a controlling interest. Ellis stayed on as co-founder and board member. Relativity reported a Terran R backlog above $2.9 billion, qualified its Aeon R engine in July 2025, and in June 2026 announced a NASA partnership for a Mars orbiter planned for 2028. Terran R's first launch has slipped to no earlier than 2026.
A founder can take a plain lesson from the Bezos conversation. A good idea, admired by the right person, still is not a reason to act. Ellis needed his own reason, and he built a company to prove it.