The Space Exploration Technologies rocket, standing taller than a 20-story building, blasted off at 5:37 a.m. from Space Launch Complex-4 on South Base.
The launch is part of an effort to build a second-generation constellation for a global communications system. An hour after liftoff, each Iridium Next satellite was deposited in space every 100 seconds, with full deployment taking about 15 minutes.
Monday’s mission boosts the number of Iridium Next craft in space to 30.
In all, SpaceX has been hired to conduct eight missions to deliver 75 Iridium Next satellites, with the launches planned every two months.
A total of 81 satellites are scheduled to roll off the Arizona assembly line, with 66 serving as the operational satellites to replace the existing Iridium network, officials said. The remainder will serve as spares, some positioned in space and others waiting on the ground to be called into service.
After going through an initial checkout period, each new satellite will be moved into service to replace an aging original spacecraft. Iridium officials have likened the “slot swap” to trying to change a tire on a car moving at 17,000 mph.
The majority of the first-generation Iridium satellites also launched from Vandenberg.