SpaceX returns to flight with delivery of 10 satellites to orbit

Photograph by Peter Merlin

The Iridium NEXT satellites are encapsulated prior to launch.

SpaceX celebrated a successful return to flight of the company’s Falcon 9 rocket following a four-month hiatus while investigators sought to determine the cause of an explosion that occurred during ground operations in Florida.

The Jan. 14 launch from Vandenberg Air Force Base, Calif., carried a group of 10 Iridium NEXT communications satellites into low Earth orbit to begin replacing the company’s current fleet of satellites in providing global voice and data relay services.

This launch was only the beginning. Iridium signed a $492 million deal with SpaceX in 2010 to orbit a total of 72 spacecraft including 66 active units and six on-orbit spares. Each of the latest generation of Iridium satellites is capable of providing more than 6.1 million square miles of coverage. According to Iridium CEO Matt Desch, “This is one of the largest commercial satellite systems being built today.”

In order to meet Iridium’s precise orbital requirements, liftoff of the Falcon 9 had to take place within a one-second launch window. Following separation of the rocket’s second stage, the first stage automatically started maneuvering for return to Earth. Just 10 minutes after leaving Vandenberg, the first stage touched down safely aboard a platform on the ocean off the coast of California. This was the fifth successful recovery of a SpaceX rocket at sea. About an hour later, a company spokesman reported that the satellites had been released into their intended orbits.

SpaceX CEO Elon Musk is hoping the results of this first Iridium NEXT deployment will restore confidence in his company’s ability to provide reliable launch services.

An artists’ impression of the Iridium NEXT satellite on orbit.

Last September, during fueling in preparation for a static firing test, a similar Falcon 9 booster exploded at Cape Canaveral, Fla., severely damaging the launch pad and destroying its payload, the Israeli-owned AMOS-6 television and Internet communications spacecraft. A four-month-long investigation determined that the explosion was most likely triggered by the sudden failure of a tank of high-pressure helium that was exposed to liquid oxygen at temperatures of minus 340 degrees Fahrenheit inside the Falcon 9’s second stage. SpaceX engineers suspect that frozen liquid oxygen trapped inside buckles between the helium tank’s aluminum liner and a carbon overwrap somehow ignited.

“It was a really surprising problem, said Musk. “It’s never been encountered before in the history of rocketry.”

On Jan. 6, the Federal Aviation Administration signed off on the SpaceX investigation, granting a license for all seven Falcon 9 Iridium launches currently on the company’s manifest through early 2018. SpaceX planned to return to flight as early as Jan. 8, but the launch was postponed due to rain and heavy winds, as well as unspecified range conflicts.

In the field of commercial spaceflight, launch delays have serious financial consequences. The mishap investigation forced SpaceX to push back all of its scheduled launches last year, including the first flight of its new Falcon Heavy, a larger vehicle that will provide heavy-lift capabilities for large payloads. The company also had to postpone a milestone demonstration in which it will re-use one of its previously flown first-stage boosters. As a result of the schedule delays, SpaceX customer Inmarsat opted to cancel its booking and instead launch one of its communications satellites on a European Ariane 5 rocket. A November report in The Wall Street Journal revealed that SpaceX experienced a $260 million annual loss following the rocket explosion in 2015, as well as a six-percent drop in revenue.

A SpaceX Falcon 9 rocket lifts off from Vandenberg Air Force Base, Calif., Jan. 14. The rocket carried a group of 10 Iridium NEXT communications satellites into low Earth orbit. This was the first SpaceX launch after a four-month hiatus brought on by an explosion during ground operations in Florida last year.