Geostationary configurations, most of which orbit high above the Earth’s equator, have a long history within satellite communications. While coverage from geostationary satellite systems is near complete, the “newcomers” – Low-Earth Orbit (LEO) satellite arrays – have now matured to the point of offering even greater global communications coverage.
Iridium Communications Inc, operator of the world’s largest commercial LEO communications constellation – now in its second generation with 66 cross-linked satellites – provides full coverage of the Earth’s surface, including polar regions. This constellation supports the Iridium Certus multi-service platform, which offers data communications on the L-Band, supporting critical connectivity for maritime, aviation, land mobile and IoT.
Describing the Iridium constellation’s scope, Will Kraus, Iridium’s Director for the Maritime Line of Business, says, “We’ve completed the new constellation, so we have 66 satellites operational, plus we have 9 on-orbit spares – and we’ve got 6 on the ground, too – for a total of 81 satellites. And they’re all up – working, functioning – and everything’s backwards compatible.”
“It’s really important that these systems are backward compatible so that everything continues to work, which it does. But now for the new system we launched in 2019, called Certus, we have new hardware –including several new user terminals,” Kraus adds. “Right now, it’s 352 kb per second service and bidirectional, and later this year there will be a firmware downlink upgrade so it’s going to be 704 kb on the downlink and 352 kb on the uplink.”
“One of the unique aspects about the Iridium system, even when it was first launched, was the ability to upload new software to the satellites – and reprogram, making updates if you need to,” explains Jordan Hassin, Director of Corporate Communications at Iridium.“In addition, our design can solve potential, unexpected problems. We can also increase the lifespan by making specific capability updates. So, this fits exactly into that same process – satellites get new software and the firmware can be activated.”
Supporting safety in a big way
The full coverage of the latest iteration of the Iridium constellation has made it possible for Iridium to offer additional new services.
Earlier this year, Iridium and the International Mobile Satellite Organization (IMSO) signed a Public Services Agreement (PSA) that detailed the conditions for IMSO to act as regulator and maintain oversight of Iridium’s Global Maritime Distress and Safety System (GMDSS) services. This was a key step in the process towards IMSO issuing Iridium a Letter of Compliance, stating that the company is ready to begin providing its GMDSS service.
By mid-year, along with partner Lars Thrane, Iridium unveiled the Lars Thrane (LT) 3100S terminal designed to operate on the Iridium network for Global Maritime Distress and Safety System (GMDSS) vessel carriage requirements, with service targeted to launch in January 2020.
The LT-3100S not only offers an all-in-one system that can meet Safety of Life at Sea (SOLAS) convention vessel carriage requirements, it also can serve as a primary or companion communications system. For the first time, with Iridium as a GMDSS provider, the coverage of this service has been extended to 100% of the planet’s waterways, including the Arctic and Antarctic.
Small package for Big Data
“We are also very big in the sensor market and have an incredibly small chipset that can communicate directly with our satellites, using our short burst data,” says Will Kraus. Holding up a chip not much larger than a postage stamp, he continues: “This will communicate directly with the satellite. While it’s low speed, it’s very straightforward, and we resell it through partners who then develop products based around it. Sensor packages, buoys, alarm systems – any sort of installation you could imagine. Also, you could have multiple sets of these chips – and they can work within proximity of each other.”
Although typical chipsets require more pointing accuracy, Kraus explains that “our chips are beam switching all the time, they’re looking at multiple beams in our system at any given moment. We’ve done tests where these the chips are definitely able to track more than three beams at a time – and they’re switching fast, at multiple times per second.”
“A good example of applying this flexibility is The Ocean Cleanup – they’re using our chips on all of their long floaters,” adds Kraus. “They have a number of sensors installed along each floater, all constantly collecting data. And they have our broadband terminals in key spots, so all the collected data is communicated.”
More to come
It’s been a busy year for Iridium, after finalising the complete replacement of its first-generation satellites. Stay tuned – we’re sure to hear more about how Iridium is working with its partners to develop specialised broadband, midband and narrowband applications only possible through Iridium’s crosslinked L-band network.