Launch of Iridium-4 on December 22, 2017.

It is brief but informative as an announcement from Iridium provides status of their next launch of NEXT satellites.

Update – February 28, 2018

Iridium Communications Inc. announced that the fifth Iridium NEXT launch has been targeted by SpaceX for March 29, 2018 at 7:19 am PDT (14:19 UTC) from Vandenberg Air Force Base in California. This launch will use the same Falcon 9 first stage as the Iridium-3 launch that took place in October 2017 and begin a rapid-cadence launch schedule targeting completion of the Iridium manifest by mid-2018.

Iridium is replacing its existing constellation by sending 75 Iridium NEXT satellites into space on a SpaceX Falcon 9 rocket over 8 different launches.