Ian M. Ross, who helped perfect the transistor and calculate whether the moon’s surface could support a spaceship’s weight, and then went on to lead Bell Laboratories, the legendary fount of technological marvels and Nobel Prize winners, died on March 10 at his home in New Smyrna Beach, Fla. He was 85.

The cause was complications of pneumonia, his wife, Christina, said.

For much of the 20th century Bell Labs was among the world’s largest research institutions. Its mission was to help AT&T, the telephone monopoly and its corporate parent, cope with everything from digital communication to squirrels chewing phone lines. Its thousands of scientists and engineers fostered discoveries like the transistor, the laser and information theory, earning seven Nobel Prizes and 29,000 patents....