Most of the stories we write about the United States’ military focus on technological advancements. This one will be a bit different. The United States Navy is now teaching sailors to find their way by the stars. 1,200 midshipmen with the Naval Reserve Officer Training Corps will learn the low-tech skill this year.

Celestial navigation is way out of fashion. The reliance on GPS has made the skill all but irrelevant. Yet there is a growing suspicion that digital technologies such as GPS are vulnerable to hacking. If there’s no old-school back-up, an entire fleet could be dead in the water.

The skill hasn’t been taught since the 1990s.

While primitive cultures have been using stars to navigate for countless years, the sextant, a tool perfected in the 1800s, allows for extreme precision. It works by measuring the distance from a star to the person. The sextant then allows observers to triangulate themselves between the celestial body and the horizon.

The Daily Mail reports that the program was “created by Vanderbilt University researcher, called VandyAstroNav .” The program is available on the internet, if anyone wants to play along.

Researchers at Vanderbilt are leading the training. Dr Susan Stewart, shown above on the guided missile destroyer USS Spruance, is one of the team leaders. Dr. Stewart also works as an astronomer at the US Nasal Observatory. She is the one who envisioned the high-tech online lessons for the old-school navigational tool.

“I thought it was important to reduce the impediments to celestial navigation, particularly as the vulnerabilities of satellite navigation have become apparent, so it can serve as a viable backup for navigation,” she told the Mail.

The initial success of the program has been encouraging, and there are efforts in place to get the curriculum back in the traditional classroom, beginning with the U.S. Naval Academy.

If successful, the Navy will have a growing team of experts ready to stand in at the first sign of a navigational emergency.