Quartermaster Seaman Pasquale V. Verrastro uses a sextant to find the range of a foreign vessel on the bridge wing of the guided-missile destroyer USS Ramage. (U.S. Navy photo by Mass Communication Specialist 2nd Class Jared King/Released)

Steering a ship by the stars fell out of favor with the rise of radio wave and GPS navigation. In fact, the U.S. Naval Academy stopped teaching the skill nearly 20 years ago.

But now this ancient navigation is making a comeback at the Annapolis school, thanks to cybersecurity fears, according to the Capital Gazette.

"We went away from celestial navigation because computers are great,” Lt. Cmdr. Ryan Rogers, the deputy chairman of the academy's Department of Seamanship and Navigation, told the Gazette. “The problem is, there’s no backup."

For now, the training is limited: Just a three-hour course covering the basics. But it's part of a larger trend.

As governments grapple with the rise of threats in cyberspace -- and increasingly realize that they may not be able to stop all of them -- old-fashioned techniques are being dusted off as a fail-safe. A security force that guards high-ranking Russian officials, for instance, reverted to using typewriters after revelations about U.S. digital spying capabilities, local news outlets reported. German officials have considered a similar move.

After the Naval Academy cut celestial navigation training, the practice began to peter out. It ended for the Navy at large in 2006, but was brought back for ship navigation officers in 2011. The Navy is now rebuilding a program for all enlisted ranks, the Gazette reported.

But even if a government agency doesn't want to take computers out of the equation entirely, some experts suggest finding ways to add in checks that live outside a network.

"Merge your system with something that is analog, physical or human so that the system, if subverted digitally, has a second barrier to get over," said Richard Danzig, vice chairman of the global security think tank RAND Corporation and a former Clinton-era secretary of the Navy, during a talk at New York University last December.

"If I really care about something — for example my command and control systems or my nuclear systems or maybe my bank account — I want some requirement not just that there be a digital input, but that there be some human input or other kind of secondary consideration," he said.