Tesla has begun building its Optimus humanoid robot at its Fremont, California, plant, repurposing space previously used for Model S and Model X assembly, as Elon Musk describes the project as Tesla’s hardest manufacturing challenge. Fremont is intended to establish processes for mass production at Giga Texas in Austin, but Musk expects the initial production S-curve to be flat and long because every component is new and Tesla must create an entire supply chain or manufacture parts internally. Jason Calacanis predicts 1 billion Optimus robots will operate worldwide by 2036 and says the product could provide more value than Apple’s iPhone, although investors and robotics executives remain skeptical. Tesla’s newer 2026 spending plan exceeds $25 billion, compared with an earlier figure of more than $20 billion, and is expected to rise in 2027 and 2028. At the same time, Tesla has removed its Solar Roof glass-tile product from its website and stopped accepting new orders, continuing to sell conventional solar panels, Powerwall batteries and Megapack storage.