It appears that the 50+ year continuous record from the DMSP satellites may be at risk.
From Wiki:
"2016 failure of DMSP 19 without replacement
"On 11 February 2016, a power failure left both the command-and-control subsystem and its backup without the ability to reach the satellite’s processor, according to the US Air Force Space Command investigation released in July 2016 that also announced that DMSP 5D-3/F19 was considered to be ‘lost’. The satellite's data can still be used, until it ceases pointing the sensors towards the Earth. The satellite was the most recent on-orbit, having been launched on 3 April 2014.[8]
"The failure only left F16, F17 and F18 – all significantly past their expected 3–5 year lifespan – operational. F19’s planned replacement was not carried out because Congress ordered the destruction of the already constructed F20 probe to save money by not having to pay its storage costs. It is unlikely that a new DMSP satellite would be launched before 2023; by then the three remaining satellites should no longer be operational."
Thanks for the link.
I’ve found a few dead links to the data, but nothing functioning except for nighttime lights.