What are the legacy GPS system stats? Its kinda important to compare before deciding the Russians hacked them.<p>Its surprisingly difficult to find real, detailed data about the GPS system. The block II first production run of GPS sats that were launched around 1990 and decommissioned in at most 17 years had a design life of a pitiful 7 years and used dual Rb clock and Cs clocks. I'm not sure the modern block details are declassified. Anyway the failure rate for Galileo seems consistent with a "less than a decade design life" I'm not sure block IIIa is even finished designing yet.<p>People have this peculiar idea that "the gps satellite" was launched one time in the 80s and its been running ever since... not so, gosh there must have been a hundred or so launched over the last couple decades.<p>I have some limited experience with Rb-standards and on the ground in telco land you'll get an amazing song and dance from the mfgr about how in theory they should run for eternity but being a vacuum tube (actually conceptually closer to a fluorescent light) they do wear out and end up on ebay after a decade or so for ham radio microwave and EME operators to do peculiar things with them cheaply. Not good enough to run a data center is still stable enough to help bounce signals off the moon.<p>I have no experience with hydrogen standards they don't even appear on ebay in my price range. Again perhaps its normal for them to wear out, etc.<p>So Rb standards "should" die off on a regular basis. Possibly the biggest classified secret of the entire GPS project MIGHT be you have to massively overspec your clocks or you get an economic kill shot of spending a billion bucks (rubles, euros) on something that only runs six months LOL shoudda just licensed our technology that learned the lessons the hard way in developmental block I satellites in the mid 80s.