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Iridium launch to make historyIridium launch to make history

Dec. 22 mission reuses SpaceX rocketDec. 22 mission reuses SpaceX rocket

Iridium Communications Inc. is making final preparations for its next launch. Iridium-4 is scheduled to lift off from Vandenberg Air Force Base, California, at 5:32 p.m. Pacific Standard Time Dec. 22. The backup launch date is Dec. 23. The company said the launch marks the midway point of its launch campaign with SpaceX, lofting the fourth set of 10 Iridium NEXT communication satellites, and will be the first Iridium launch to reuse a “flight-proven” SpaceX Falcon 9 rocket.

A SpaceX Falcon 9 rocket launches the first 10 Iridium NEXT satellites, on January 14, 2017. The fourth Iridium launch, scheduled for December 22, will use the same Falcon booster that launched the second Iridium payload on June 25, 2017. Photo courtesy of SpaceX.

The launch will use the same Falcon 9 rocket first stage that carried 10 Iridium NEXT satellites on the company’s second launch, in June 2017. Iridium said the launch will make it the first company in history to reuse the same rocket.

Each Iridium NEXT satellite carries the Aireon Automatic Dependent Surveillance-Broadcast (ADS-B) payload. The first 10 satellites were launched in January 2017, and Iridium and Aireon have been working to validate the performance of the 30 ADS-B receivers now in orbit. 

“We’re approaching our halfway point on this journey, and with each launch, we gain more momentum,” said Iridium CEO Matt Desch. “This launch will bring us to 40 Iridium NEXT satellites in space, which is more than half the number required for a full Iridium NEXT operational constellation. It has been remarkable to witness the increased speed, capacity, and throughput of our network as we continue to replace our original satellites with new Iridium NEXT satellites.”

Iridium says that it is fully confident in the SpaceX booster refurbishment program. “I believe that reusability is the future for satellite launches, and I think SpaceX has intelligently built their Falcon 9 program around this strategy,” Desch said. “With three successful flight-proven Falcon 9 launches already this year, we’re excited to show leadership towards the sustainable access to space, while also making sure we maintain our cadence to complete the five remaining Iridium NEXT launches by the middle of next year.”

Iridium NEXT satellites, left center, are shown installed in the launcher and ready to be enclosed in the SpaceX rocket's payload capsule. One launch can place 10 of the satellites into orbit. Photo courtesy of Aireon.

Iridium confirmed with its insurers that there is no increase in premium for the launch program as a result of reusing Falcon 9 rockets, reinforcing the company’s conclusion that the risk profile is unchanged, Iridium said in a news release. Iridium will reuse a Falcon 9 for its fifth launch, as well.

The operational Iridium constellation will be composed of 66 satellites divided into six polar orbiting planes, with 11 satellites in each plane. Destined for Iridium orbital plane two, nine of the 10 Iridium NEXT satellites deployed during this launch will immediately go into service following testing and validation. The remaining satellite will undertake a nearly year-long journey to orbital plane one, where it will serve as a spare satellite.

Iridium has contracted with SpaceX to deliver 75 Iridium NEXT satellites to orbit, 66 operational and nine on-orbit spares, through a series of eight launches. Iridium NEXT is the company’s $3 billion next-generation global, mobile satellite network scheduled for completion in 2018. Iridium NEXT will replace the company’s existing global constellation in what it says is one of the largest technology upgrades ever completed in space.

Mike Collins

Mike Collins

Technical Editor
Mike Collins has worked for AOPA’s media network since 1994. He holds a private pilot certificate with an instrument rating.
Topics: Technology, ADSB

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