What’s old is new again, at least at the US Naval Academy.

Officials are adding classes in celestial navigation back to the curriculum nearly two decades after it was decided such training was no longer needed.

In the 1990s, the advent of the Global Positioning System (GPS) rendered the ancient practice of using the heavens to chart a course obsolete. However, hacking concerns forced the navy to reconsider its dependence on modern technology.

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

Celestial navigation was completely phased out of naval training in 2006, but was brought back for officers training as ship navigators in 2011. Now, the navy is rebuilding the program so that all enlisted service members will eventually be trained.

“Knowledge of celestial navigation in the GPS era provides a solid back-up form of navigation in the event GPS becomes unreliable for whatever reason,” instructor Capt. Timothy Tisch said in a statement. “It is also good professional practice to use one navigational system to verify the accuracy of another.”

(Source: Capital Gazette, H/T: The Telegraph)