Whether an AI company can build its next model depends not only on compute, but on whether its researchers are still there. xAI merged into SpaceX in February 2026 (the AI division is now called SpaceXAI). By the end of March 2026, everyone on its founding team except Musk had left.
This piece covers who left, who took over, and how to judge the impact on Grok models. To get to know SpaceX and its AI map first, see What kind of company is SpaceX.
Who left
xAI’s founding team had 12 members (including Musk).
On February 10, 2026, TechCrunch reported that 6 had left, exactly half:
- Kyle Kosic (former OpenAI engineer)
- Christian Szegedy (former Google researcher, a key figure behind Batch Normalization)
- Igor Babuschkin (formerly at Google DeepMind and OpenAI)
- Greg Yang (formerly at Microsoft Research, a lead in theory research)
- Yuhuai Wu (formerly at Google, a math-reasoning researcher)
- Jimmy Ba (University of Toronto professor, co-creator of the Adam optimizer)
Five more left after that. On March 28, 2026, TechCrunch, citing Business Insider, reported that the last two, Manuel Kroiss (who led the pre-training team) and Ross Nordeen, had also left.
The whole founding research team has been replaced.
Who took over
As of October 2026, the company has not published a full AI leadership org chart. What we know:
- Musk is still CEO of SpaceX.
- Since April 2026, Michael Nicolls, Starlink’s senior vice president of engineering, has been president of SpaceXAI (according to Business Insider).
- According to Bloomberg in July 2026, Nicolls now runs the engineering team, and his near-term goal in an internal memo was to “catch up to Claude’s performance.”
Startup norm or warning sign?
Founder turnover is common in fast-scaling startups. Some finish a stage of work, some start their own companies, some leave over differences in direction. But “everyone left” is a different level of signal from “half left,” especially when the people leaving are the research backbone.
Two readings coexist. The pessimistic one: a gap in the research team could slow model progress. The neutral one: xAI has gone from an independent startup to a division of SpaceX, a public company, and a new set of managers is part of that transition. The only thing outsiders can confirm is how often models actually ship.
What to watch: Grok’s release cadence
A talent drain hurts most in the “ability to build the next model,” so the most concrete test is the models themselves.
| Date | Event |
|---|---|
| January 2026 | xAI says Grok 5 is in training |
| July 8, 2026 | Grok 4.5 released |
| August 12, 2026 | Grok 4.6 released |
| September 21, 2026 | Grok 4.7 available in the API |
After the founding team left, Grok 4.x has kept shipping roughly one version a month. But as of October 2026, Grok 5 has no release date. According to Digital Today, Musk said on September 14, 2026 that Grok 4.8 and 4.9 will come before Grok 5, and that Grok 4.7 is roughly on par with Anthropic’s Opus 5.0 but not yet at 5.1.
For Grok’s model line, see Why Grok went open, then closed.
Penchan’s summary
Losing the whole founding team is a stronger signal than “half left,” but it doesn’t directly mean the model can’t be built.
The new management has set its sights on Claude. When Grok 5 ships, and whether it catches up with rivals, is the real answer sheet for this personnel shake-up.