Biographer Walter Isaacson and others close to Musk have previously described Musk’s periods of extreme productivity—and extreme temper—as “demon mode.”

Boeing has lost more than $2 billion producing the Next Air Force One after President Donald Trump renegotiated the deal in his first term.

Elon Musk has taken on a new role as the First Buddy: monitoring the progress on the long-awaited revamped Air Force One jets. The new Air Force One planes, made by Boeing, are currently $2.7 billion over budget and three years behind schedule.