On Tuesday, Elon Musk had a Tesla Roadster launched toward an orbit around the sun. A day later, he and his car company came back to earth.

The electric-car maker said Wednesday that it lost more than three-quarters of a billion dollars in the fourth quarter as it scrambled to root out glitches from its manufacturing operations and ramp up production of its highly anticipated Model 3 sedan.

In a conference call with analysts, Mr. Musk, the chief executive, acknowledged that Tesla still faced challenges in putting the Model 3 into mass production. “We were in a deeper level of hell than we expected, still a few levels deeper than we would like to be,” he said.

The company reported a quarterly net loss of $771 million, more than tripling the loss it reported for the same period a year earlier. Revenue increased 44 percent to $3.3 billion, on rising sales of its Model S luxury sedan and Model X, a sport-utility vehicle.