First Iridium NEXT satellites shipped to Vandenberg
On Tuesday, August 2, a specially designed semi-trailer truck safely delivered the first two spacecraft of the next generation of Iridium global mobile telecommunications satellites to SpaceX’s clean room at Vandenberg Air Force Base in California.
The initial Iridium NEXT satellites will be joined by eight more siblings sent from Orbital ATK’s Satellite Manufacturing Facility in Gilbert, Arizona. All ten vehicles, each weighing 1,896 pounds (860 kilograms), will be placed aboard a SpaceX Falcon 9 rocket for delivery into low-Earth orbit scheduled for Sept. 19, 2016.
“We’re excited for the upcoming first launch of Iridium NEXT and proud of the work we’ve completed for the Iridium NEXT program,” said Kris Kroc, mission manager at SpaceX, in an Iridium news release. “This is one of the heaviest payloads we will fly to date – 10 Iridium NEXT satellites weighing over 20,000 pounds.”
The Falcon 9 rocket will send the massive comsat cluster into a polar orbit 388 miles (625 kilometers) above Earth from Space Launch Complex 4-East at Vandenberg AFB. Once the Iridium NEXT satellites complete their series of spacecraft system checks over the next three months, they will then be boosted to an even higher altitude of 485 miles (780 kilometers).
There they will join – and eventually replace – the first generation of still-operational, yet aging, Iridium comsats in the company’s communications constellation, which were assembled between 1997 and 2002 to provide voice and data coverage to satellite phones, pagers, and integrated transceivers over the entire surface of Earth.
Iridium NEXT will consist of a fleet of 81 communications satellites: 66 are meant for operational use, 6 are in-orbit spares, and 9 are ground spares. All satellites should be in space by the end of 2017.
This new generation of global mobile comsats will have several significant advantages over their predecessors. These improvements include an expanded service capacity, higher data speeds, and the ability to host payloads up to 120 pounds (54 kilograms). The satellites, designed by Thales Alenia Space, will each have an operational lifetime of up to 15 years.
According to the Orbital ATK Iridium NEXT fact sheet, each spacecraft employs an L-band phased array antenna for generation of the 48-beam, 2,920-mile (4,700-kilometer) diameter cellular pattern on Earth’s surface for communication with subscribers. Additionally, Ka-band links are also provided for communications with ground-based gateways and for cross-links with adjacent spacecraft in orbit. The cross-linked 66-satellite constellation forms a global network in space allowing communications from a ground or airborne user from any location on Earth to anywhere else on Earth.
The owners of Iridium NEXT, Iridium Communications, Inc., are spending almost $3 billion on the new satellite program. According to Spaceflight Now, Matt Desch, Iridium’s chief executive, calls it the biggest tech refresh in the history of satellite communications.
“The Iridium NEXT program has been more than seven years in the making, and is one of the most complex satellite programs underway today,” Desch said on July 28 in a quarterly earnings call.
As for SpaceX meeting the tight launch schedule for assembling the Iridium NEXT constellation in orbit, Desch said SpaceX has assured him that their rockets will be on time and available.
“There’s always going to be a little movement around the final date, whether it be a short-term issue, or it could even be weather,” Desch said. “But we really expect to keep on that pace all the way through the final launch, and the satellites that come into operation shortly thereafter.”
The original Iridium program was given its name after the 77th element on the periodic table of elements. That is the number of comsats which were envisioned for the constellation, but, eventually, that amount was scaled back to 66. The name has remained with the new generation of comsats.
Additionally, backyard astronomers can catch the bright glint of sunlight off the large solar panels attached to each satellite. They are known as “Iridium flares”. Soon they will have an entirely new crop of Iridium solar panels to witness flashing Earth.
Larry Klaes is an author and freelance journalist specializing in news and educational work on the sciences. Klae's past endeavors include editor of SETIQuest magazine and President of the Boston chapter of the National Space Society (NSS). Klaes joined SpaceFlight Insider in 2016.