Like many other technologies, one might assume that celestial navigation has only been truly developed efficiently in recent times with our technology. But you may be surprised to know that many of the techniques we use today were invented centuries ago, or even thousands of years!
Celestial navigation is the practice of using angles between celestial bodies and the earth’s horizon to determine one’s location, especially at sea. Tools like sextants are especially useful for this, and have been around for centuries- there have been documented usages of such a tool going as far back as the 1500s. It makes sense that such a simple yet effective tool has remained a consistently useful tool for navigation; in modern times, it provides a crucial backup if electronic navigation systems should encounter difficulties. In fact, the U.S. Naval Academy (among other institutions) has recently reimplemented celestial navigation courses, recognizing its longstanding usefulness.
Celestial navigation has been a mainstay of exploration for ages, and the main principles have largely stayed the same.
Danny's Solar System Blog 