The primary objective of Sunday's mission was to place the SAOCOM 1A satellite into orbit, but SpaceX also successfully sent a first stage booster back to the base for the first time.
SpaceX has successfully recovered a Falcon 9 Block 5 booster on a land-based landing zone for the first time in the rocket's brief history, marking the debut of the company's West Coast LZ-4 and the second flight of a reused Block 5 booster.
Nearby residents in Santa Barbara, Ventura and San Luis Obispo counties were warned they "may hear one or more sonic booms" from the landing.
A SpaceX Falcon 9 rocket lifts off from a launch pad in Florida on March 30, 2017. Previous re-capture missions from Vandenberg have landed the rocket on a barge floating in the Pacific Ocean, about 400 miles out to sea. "This won't be subtle".
The satellite is the first of two from Argentina. The instantaneous launch opportunity is on Sunday, October 7 at 7:21 p.m. PDT, or Monday, October 8 at 2:21 UTC, and the satellite will be deployed about 12 minutes after launch. The satellite is created to provide radar imagery to help emergency responders and monitor the environment, including the collection of soil moisture measurements.
The first stage, meanwhile, flipped around and re-started three of its nine engines to reverse course and head back toward Vandenberg.
SpaceX has a goal of using the boosters up to ten times with little maintenance, and 100 with refurbishment, as well as being able to relaunch boosters 24 hours after landing. There's no specified launch window, and that could force SpaceX to move liftoff to October 11th if it has to scrub the launch on the 7th.