SpaceX Falcon 9 Block 5 - Iridium-7 Next - Launching July 25, 2018
Screenshot of Iridium 7 launching through the fog with Everyday Astronaut Tim Dodd as host
Mission Rundown: SpaceX Falcon 9 - Iridium-7 NEXT
Written: January 10, 2021
Almost done with the big job
SpaceX will be launching the 7th and second to last mission for Iridium. This launch will place the 10 Iridium Next satellites in low Earth polar orbit bringing the number of satellites to 65. The previous six missions, beginning with Iridium 1 on January 14, 2017, have already delivered 55 Iridium Next satellites to orbit.
The booster B1048-1 is on its maiden flight into space, so it's been a short journey from Hawthorne to the 4 East launchpad on Vandenberg Air Force Base SLC 4E.
Sorry. No old screenshot of the Iridium 7 mission view was made by Geoff Barrett
SpaceX is preparing to launch their 13th Falcon 9 rocket this year. This mission, Iridium-7, is the 7th overall mission for customer Iridium Communications. This will be SpaceX’s third launch for Iridium this year! They'll also be attempting to land the booster, AND recover the payload fairing! Which is super exciting!
This launch will take place at Space Launch Complex 4E - SLC-4E at the Vandenberg Air Force Base. It will be the first flight for this Falcon 9 block 5 rocket, core B1048, and the third flight overall for a Falcon 9 block 5.
Iridium-7 NEXT deployment
The 10 Iridium-NEXT satellites in flight 7 were deployed into the existing constellation 625 km under the existing Iridium Block 1 constellation in orbit plane 5. After the initial health check of the satellites they will one by one raise their orbits to 778 km altitude and become operational by relieving the old Iridium Block 1 satellites, as they are reported ready and able to assume their post.
In the lower 625 km insertion orbit the 10 Iridium-NEXT satellites in flight 7 were orbiting faster than the old existing Iridium Block 1, so every time a old satellite were intercepted from below, one of the 10 Iridium-NEXT satellites would perform two burns to raise its orbit and then circullice its orbit just above the old Iridium Block 1 satellite. A flick of a control switch would swab the signal traffic between them from old to new.
The relieved old Iridium Block 1 satellite would now be deorbited by using the very last fumes of propellant to break the orbit, lowering it, until it reached the atmosphere and was deorbited preferably over an empty stretch of south pacific ocean. The satellite propellant was from the beginning used to reach its operational orbit and keep it in place during its operational life in the 778 km polar orbit, while it was receiving and relaying data between the customers and their items of commercial interests.
With this launch all satellites in orbit plane 5 will be Iridium NEXT satellites, and when the spare Iridium NEXT satellite SV 153 shifts its orbit plane from 6 to 5, then orbit plane 5 will be complete with 11 Iridium NEXT satellites, and the Iridium NEXT constellation will have 60 Iridium NEXT satellites in place except for only 6 elderly Blok 1 Iridium satellites.
The upcoming last Falcon 9 launch Iridium-8 NEXT will replace the last 6 Iridium satellites and replace 4 old spare satellites as well. SpaceX has actually used three different Falcon 9 block models 3-5 as launch vehicles to loft the Iridium constellation into orbit.
The second-generation Iridium-NEXT satellites began to be deployed into the existing old constellation in January 2017. Iridium Communications, the successor company to Iridium SSC, has ordered a total of 81 new satellites being built by Thales Alenia Space and Orbital ATK: 66 operational units in 6 orbit planes, nine in-orbit spares, and six ground spares.
In August 2008, Iridium selected two companies — Lockheed Martin and Thales Alenia Space — to participate in the final phase of the procurement of the next-generation satellite constellation. As of 2009, the plan was to begin launching new satellites in 2014.
The design was complete by 2010, and Iridium stated that the existing constellation of satellites would remain operational until Iridium NEXT is fully operational, with many satellites expected to remain in service until the 2020s, while the NEXT satellites would have improved bandwidth.
The new system was to be backward-compatible with the current system. In June 2010, the winner of the contract was announced as Thales Alenia Space, in a $2.1 billion deal underwritten by Compagnie Française d'Assurance pour le Commerce Extérieur. Iridium additionally stated that it expected to spend about $800 million to launch the satellites and upgrade some ground facilities.
SpaceX was contracted to launch all the Iridium NEXT satellites. All the Iridium NEXT launches have taken place using a Falcon 9 rocket launch from Vandenberg Air Force Base in California. Deployment of the constellation began in January 2017, with the launch of the first 10 Iridium NEXT satellites.
In January 2020, the Iridium constellation was certified for use in the Global Maritime Distress and Safety System (GMDSS). The certification ended a monopoly on the provision of maritime distress services that had previously been held by Inmarsat since the system became operational in 1999.
The constellation provides L band data speeds of up to 128 kbit/s to mobile terminals, up to 1.5 Mbit/s to Iridium Pilot marine terminals, and high-speed Ka-band service of up to 8 Mbit/s to fixed/transportable terminals. The next-generation terminals and service became commercially available in 2018.
The NEXT satellites host an extra set of instruments and incorporate a secondary payload for Aireon, a space-qualified ADS-B data receiver for use by air traffic control and, via FlightAware, by airlines. A tertiary payload on 58 satellites is a marine AIS ship-tracker receiver for Canadian company ExactEarth Ltd.
This basically means that Iridium NEXT is a shared satellite with at least 2 customers, who - besides having their own equipment built in from the start, uses the onboard computers, receivers and transmitters to process datastreams to and from satellites, ground stations, individual data transmitters and data receiving customers.
Iridium NEXT also provides data links to other satellites in space, enabling command and control of other space assets regardless of the position of ground stations and gateways.
