Photograph by Peter W. Merlin

SpaceX launched the third set of Iridium NEXT communications satellites into orbit from Vandenberg Air Force Base, Calif., Oct. 9.

Iridium Communications is in the process of replacing its current fleet of global voice and data relay satellites in batches. SpaceX launched the first two sets of 10 in January and June. Iridium signed a $492 million deal with SpaceX in 2010 to orbit a total of 75 next-generation communications spacecraft by mid-2018.

Two hours and 15 minutes after liftoff, SpaceX Falcon 9 principal engineer John Insprucker reported that all 10 of the 1,900-pound satellites had been successfully deployed. “We’re 10-for-10, a clean sweep of Iridium satellite deployments in the desired orbit,” he said.

Replacement of the original Iridium constellation requires careful insertion of each new satellite into its operational orbit and seamless transfer of data and communications control capabilities from legacy spacecraft without impacting customers. Each of the second-generation Iridium satellites is capable of providing more than 6.1 million square miles of coverage. They are expected to provide significant improvements in call quality and data transfer speed.

Courtesy image

Stringent orbital requirements necessitated that liftoff of the SpaceX Falcon 9 booster rocket had to take place within a one-second launch window. Following separation of the rocket’s second stage, the reusable first stage maneuvered automatically for return to Earth, touching down minutes later aboard an ocean platform off the California coast some 160 miles west of San Diego. This marked the 10th successful landing of a Falcon 9 first stage at sea. Seven others touched down on land. Out of 22 attempts, the company has recovered 17 boosters intact since 2015. SpaceX refurbished the booster core from the Jan. 14, 2017, Iridium flight and used it to launch a Bulgarian communications satellite on June 23.