Celestial navigation, or the method of finding one's way through the observation of the position of the stars, is an ancient art and science.

Used for centuries, the method has fallen largely out of favor recently due to advancements in GPS technology and systems. GPS satellites were launched by the United States military in the 1970s, and the U.S. Navy officially transitioned from celestial navigation into electronic systems in 2000.

Today, the Navy has been using the Voyage Management System, which uses several tools including GPS for navigation and ship charting. With it in place, celestial navigation has long been cast aside, with the Navy stopping the training of its service members on the method.

That is, until now. The Navy is once again including celestial navigation in its naval training for its officers, despite the presence of the Voyage Management System.

The reason behind the move is, with all the benefits of GPS technology, it also has its weaknesses. The Navy, along with the other branches of the U.S. military, are growing more concerned of the increasing reliance on the technology.

"We use it to synchronize all military operations, we use it to navigate everywhere - it's just something the U.S. military can't live without," said former Air Force officer Brian Weeden.

This is a problem because, in case of a war, the military's GPS satellites could be knocked out, which would greatly damage the Navy's capabilities. In addition, jamming technology has widely developed, with different kinds of GPS jammers openly available online.

A lot of the GPS jammers are made in Russia, with Weeden believing that the Russian government has systems that could jam the GPS signals of the U.S. military. In addition, China could be developing such systems that can be used against the United States.

Even without such sabotages, GPS signals are prone to hiccups in reliability which could cause accidents. At least once over the past 10 years, a ship of the Navy ran aground due to issues in its GPS systems.

Teaching Navy officers celestial navigation will allow them to still safely navigate the ocean even if their GPS systems have been knocked out or malfunctioning.

Rear Admiral Michael White, the head of training for the Navy, said that there is also a need to teach officers the basics of ocean navigation. Teaching celestial navigation will ensure that the users of the Voyage Management System understand its fundamentals.