Spaceflight Insider

SpaceX readies Falcon 9 for launch with 10 Iridium NEXT satellites

A file photo of the previous Iridium NEXT mission, Iridium-4, which launched Dec. 22, 2017. Iridium-5 is slated to launch on March 30, 2018. Photo Credit: Iridium Communications

A file photo of the previous Iridium NEXT mission, Iridium-4, which launched Dec. 22, 2017. Iridium-5 is slated to launch on March 30, 2018. Photo Credit: Iridium Communications

The next 10 satellites that will form the Iridium NEXT constellation of communication satellites are slated to launch atop a SpaceX Falcon 9 rocket at 7:14 a.m. PDT (10:14 a.m. EDT / 14:14 GMT) March 30, 2018, from Space Launch Complex 4E (SLC-4E) at Vandenberg Air Force Base (VAFB) in California.

Originally slated for March 29, 2018, the launch was ultimately delayed to March 30 because of an issue with one of the satellites making up the payload, according to a tweet from the Iridium Communications CEO, Matt Desch. When it does launch, the Iridium-5 mission will send the fifth set of 10 Iridium NEXT satellites into orbit.

The Iridium NEXT satellites are designed to provide better call quality and faster data transfer speeds to Iridium’s growing customer base. In addition, they will allow the company to offer internet services to their customers.

The 10 Iridium-3 satellites are mated and stacked in preparation for encapsulation. The spacecraft for the Iridium-5 mission will are stacked in a similar way. Photo Credit: Iridium Communications

The 10 Iridium-3 satellites are mated and stacked in preparation for encapsulation. The spacecraft for the Iridium-5 mission will are stacked in a similar way. Photo Credit: Iridium Communications

Manufactured by Thales Alenia Space in partnership with Orbital ATK, they replace the original Iridium constellation which was first launched 20 years ago. According Iridium Communications, the next-generation satellites will deploy into a cross-linked low-Earth orbit architecture to provide coverage over the entire surface of Earth, including across oceans, airways and polar regions.

Iridium Certus is the new service platform supported by the Iridium NEXT constellation. According to the company:

“Iridium Certus makes broadband truly mobile. By offering a range of speeds from 22 kbps and eventually all the way up to 1.4 Mbps once fully deployed.

“Iridium Certus is designed to support a full range of versatile applications for any market, and any need on the ground, in the air and at sea — all in a single platform. It is ideal for maritime and aviation operational communications and safety services, extending land-mobile networks, delivering secure government communications, and unlocking powerful new M2M possibilities in asset tracking, fleet management, remote monitoring, command and control and other intelligent data applications around the globe.”

Fully loaded with propellant, each satellite weighs in at 1,896 pounds (860 kilograms), bringing the total weight of just the 10 satellites to 18,960 pounds (8,600 kilograms).

For this flight, as has been the case for the previous two Iridium NEXT missions, SpaceX is utilizing a previously-flown Falcon 9 first stage. This one, designated as core 1041.2, is the same block 4 stage that was first used to place the third set of 10 Iridium NEXT satellites into orbit on Oct. 9, 2017.

Following a successful launch from SLC-4E at the Vandenberg Air Force Base, the booster safely landed on the Autonomous Spaceport Drone Ship “Just Read the Instructions,” which was stationed downrange in the Pacific Ocean. After a thorough inspection and refurbishment at the NewSpace company’s Hawthorne, California factory, the booster was returned to SLC-4E to be readied to send its second set of 10 satellites into orbit.

The last launch of 10 Iridium NEXT satellites, Iridium-4, occurred on Dec. 22, 2017. It also utilized a used Falcon 9 first stage. Additionally, the mission brought the planned 75-satellite constellation past the 50 percent completion mark. Ultimately, the constellation will consist of 66 active satellites serving customers while the other nine will be orbital spares.

Iridium Communications actually purchased 81 satellites (six will remain on the ground as spares in case a replacement is needed in orbit) at a total cost of $3 billion. It will take three more Falcon 9 launches to complete the deployment after Iridium-5. The final two, which have not had an official launch date set, will each deploy 10 Iridium Next satellites. 

However, the next scheduled flight, currently scheduled for sometime in May, will deploy only 5 Iridium NEXT satellites. SpaceX will also deliver two Gravity Recovery and Climate Experiment Follow-On (GRACE Follow-On) spacecraft for NASA and the GFZ German Research Center for Geosciences in Germany on that flight.

Following the successful deployment of the Iridium NEXT satellites, the original legacy satellites will ultimately be deorbited and allowed to burn up in the Earth’s atmosphere. According to Iridium Communications, they will be lowered to a storage orbit located about 9 miles (15 kilometers) below the operational constellation. 

“Once ready to be formally deorbited, the old satellite undergoes a NASA recommended decommissioning process, with the goal of reaching the lowest possible orbit while using up all its remaining fuel,” the company stated in a May 2017 update. “At that point, the satellite will automatically deplete its battery and, over time, get caught in a slow burning orbit until it completely disappears in the earth’s atmosphere.”

The Iridium NEXT satellites are being deployed into six different orbit planes with eleven active satellites orbiting in each. After a satellite is released from its dispenser module, it will then slowly drift into its desired position in its orbital plane.

Last week Iridium completed the second of the six orbital planes the new satellites will reside in. According to a tweet from Desch, the second plane was completed March 23. All of the satellites from the Iridium-5 launch are all to be delivered into plane one. Iridium hopes to have the complete constellation launched by the end of 2018.

 

 

Tagged:

Lloyd Campbell’s first interest in space began when he was a very young boy in the 1960s with NASA’s Gemini and Apollo programs. That passion continued in the early 1970s with our continued exploration of our Moon, and was renewed by the Shuttle Program. Having attended the launch of Space Shuttle Discovery on its final two missions, STS-131, and STS-133, he began to do more social networking on space and that developed into writing more in-depth articles. Since then he’s attended the launch of the Mars Science Laboratory Curiosity rover, the agency’s new crew-rated Orion spacecraft on Exploration Flight Test 1, and multiple other uncrewed launches. In addition to writing, Lloyd has also been doing more photography of launches and aviation. He enjoys all aspects of space exploration, both human, and robotic, but his primary passions lie with human exploration and the vehicles, rockets, and other technologies that allow humanity to explore space.

Reader Comments

⚠ Commenting Rules

Post Comment

Your email address will not be published. Required fields are marked *