One of the old Pink Origin fuel depots on a medium-sized C-type asteroid, oribiting at 2.2 AU’s from the sun. 

This station was completely automated and remained in service for almost 50 years: from 2048 to 2095. Despite a very low rate of fuel production, the gigantic spherical tank was almost always full due to the low amount of customers arriving at the station. Sometimes it would go for as long as 8 years without getting a visit. 

The ships that did arrive were mostly deep space resupply missions to the outposts on Jupiter’s moons. What is lesser-known is that this was also the last refuelling stop of the infamous Kennedy expedition to Neptune’s moon Triton in 2088, which was never heard from again after its flyby of Saturn.  

The depot was permanently abandoned when propulsion by nuclear fusion became commercially viable in the late 21st century, and traditional chemical engines could not compete. However, passing ships continued to receive welcoming signals from the station’s automatic radio transmitters until the year 2124, making this fuel depot the longest-operational unmanned space station to this day.