New souvenir: Blue Switch Day 2023!

Each day, hidden technologies around the world help shape our work, our play, and our futures. One such technology is GPS, or Global Positioning System technology, which revolutionized precise location information and enabled geocaching itself!

Prior to 2000, the U.S. military created and deployed satellites to produce accurate location information for military applications. Selective Availability restricted precise GPS data to the U.S. government. On May 2, 2000, the U.S. government “flipped the switch” and made accurate GPS available to all. Geocachers proudly call this day Blue Switch Day!

Behind this incredible story are incredible people. This year, we highlight a GPS pioneer: Gladys West. At a time of few African American women in science, West worked for the U.S. Navy to develop accurate models of the Earth for satellites. West’s work in geodesy laid the foundation for GPS infrastructure. 

Photo by Adrian Cadiz. Public Domain.

West and her team employed algorithms to account for Earth’s complexities, such as the various levels of gravity worldwide as seen in the image below. West created computer programs to calculate precise satellite orbits. These calculations would become the underlying foundation for GPS.

Courtesy NASA.

After the switch was flipped and GPS became available to the public, the first geocache didn’t take long to appear! Only one day later, the first geocache was hidden on May 3, 2000. Geocaching was born! 

We’re launching a new souvenir to celebrate Blue Switch Day and the innovators who made it possible! Earn the Blue Switch Day 2023 souvenir by finding a geocache, Adventure Lab® Location, or by attending an Event between May 1–3. Happy geocaching!

Adam is the Adventure Lab® Support Manager at Geocaching HQ. Originally from the San Francisco Bay Area, you can find him laying out for a catch in ultimate frisbee, playing the baritone sax, or lacing up his boots to cache on a PNW hike.