@Tomnod Satellite average lifespan?


What is the average lifespan for most Earth Observation satellites?

I was reading this about reentry/end of life, which made me wonder, how long are most sats in use? http://www.esa.int/Our_Activities/Space_Engineering_Technology/Clean_Space/CleanSat_disposal_essential_for_swelling_satellite_population


"The WorldView-4 satellite has a design life of seven years; however it is expected to exceed this with ten to twelve years of service envisioned."

“The company’s first satellite, EarlyBird 1, was launched by a Start-1
rocket in December 1997. However, the spacecraft failed three days
after launch.
A second satellite, Quickbird-1, was lost in a Kosmos-3M launch
failure in November 2000, before Quickbird-2 successfully reached orbit
atop a Delta II the following October, achieving thirteen and a quarter
years of service before its retirement in January 2015.”

So somewhere between zero, three days, and 13.75 years…averages to 4.5 years