Global Xpress launch schedule.

(Inmarsat)

Inmarsat also operates the Ka-band Global Xpress GX5 satellite high-speed mobile broadband network,
as well as the ELERA Inmarsat-4 (I-4) which supports the global 3G narrowband L-band mobile
connectivity network. In addition, Inmarsat operates the European Aviation Network, which combines
the capabilities of its S-band satellite (I-S EAN), launched in 2017, with ground-based LTE in a hybrid air-
to-ground network and Fleet Xpress, to deliver in-flight connectivity across Europe’s airspace combining
both Global Xpress Ka-band and ELERA L-band.

Inmarsat’s satellite fleet is supported by a ground network of satellite access stations (SAS) located
across Europe, six new examples of which were commissioned in 2020 to support GX5.

Enter the I-6s

I-6 F1 data. (Inmarsat)

The newly launched sixth-generation Inmarsat-6 (I-6) satellites which will provide yet more capabilities.
Constructed in the UK by Airbus Defence and Space, the I-6 F1 was launched from the JAXA
Tanegashima Space Centre in Japan aboard an H-IIA Launch Vehicle. The second I-6 will follow in 2022.

The I-6F1 is claimed to be the largest commercial communications satellite ever launched, weighing
5,470kg with fuel. Once the solar array is extended, it will measure 47m across.

The I-6s are the company’s Inmarsat’s first hybrid satellites, fitted with both L-band (ELERA) and Ka-band
(GlobalXpress) payloads. The I-6 F1 has double the capacity per beam and double the power of the
previous Inmarsat-4 generation of L-band satellites which means that much more data can be carried
over the same amount of bandwidth. The beams can also be rerouted to match demand.

I-6 F1 under construction. (Inmarsat)

“These are the first L-band satellites that we’ve launched since Alphasat in 2013,” commented Mark
Dickinson, Deputy CTO. “The fourth generation Inmarsat-6s are very complex satellites which use the
latest digital processing technology. There is so much payload in this spacecraft that there isn’t a spare
centimetre to put in an additional piece of hardware. For the first time for Inmarsat, they’re actually a
dual band satellite with two frequency bands - an L-band satellite, which will allow us to support our
global L-band network out until the 2040s, plus enhanced Ka-band capacity in the form of steerable
beams which can be moved about to where our needs are most.”

Example of multiple beams. (Inmarsat)

Still from an Inmarsat promotional video explaining its future L-band capability. (Inmarsat)

“The Inmarsat-6 have 50% more spectrum and double the amount of processing power and double the
amount of power that we can transmit and thus we can get easily four times the amount of capacity
through the network as we do today,” says Inmarsat CTO Peter Hadlinger. “They will act as a
continuation of Inmarsat’s commitment to our customers to continue providing a global L-band network
to ensure the safety of both the aviation and maritime industries out until the 2040s.”

I-6 uses

Inmarsat believes that enhanced capabilities of the new satellites will both ‘future proof’ its existing
ELERA and Global Xpress services, as well as providing a ‘springboard for innovation’ for new emerging
technologies. These include continued maritime and aviation safety, mobile connectivity for military and
first responder networks, ISR operations, inter space communications, autonomous transport, ocean
monitoring and internet of things (IoT) innovation for agriculture, electrical utilities, mining, oil, gas
transport and logistics applications.

Seven-up satellites

The launch of I-6 F1 will be followed by six further launches, so that seven global high capacity satellites
will be in orbit by 2024, together with an expansion of the ground network. In addition to I-6 F2 in 2022,
three more Global Xpress satellites, GX7, 8 and 9, are due to be launched from 2023 which will employ
dynamic beam forming to simultaneously create thousands of reconfigurable independent beams of
different sizes, bandwidth and power. Two HEO (highly elliptical orbit) payloads, GX10A and 10B, will
offer mobile broadband connectivity over the Arctic region.

Another eight ground sites are to be commissioned by 2022 to support further regional connectivity
expansion and the new Inmarsat-6 satellites.

Introducing ORCHESTRA

Inmarsat has announced plans to combine its ELERA (L-band) and Global Xpress (Ka-band) networks with
geosynchronous orbit (GEO), targeted low earth orbit low earth orbit (LEO) and highly elliptical orbit
(HEO) satellites which, together with terrestrial 5G services, will create a ‘global, multi-dimensional,
dynamic mesh connectivity’ solution named ORCHESTRA. "An orchestra brings different instruments
together, each supporting the other and playing its role in the masterpiece,” said Inmarsat CEO, Rajeev
Suri. “We’re building ORCHESTRA on the same concept."

Artist''s impression of I-6F1 being released in orbit. (Inmarsat)

According to Inmarsat, ORCHESTRA will provide a layered approach combining the following capabilities:

ELERA: provides a critical layer of always-on connectivity with all-weather resilience.

Global Xpress: delivers reliable, high-speed, global coverage with security and full redundancy.

Terrestrial 5G: adds ultra-high capacity at specific high demand hot spots, such as busy ports, airports,
straits and sea canals.

LEO: a small, targeted constellation of 150-175 satellites layering additional high capacity over further
high demand areas.

These layers will be supplemented by a ‘dynamic mesh network’ which will allow individual terminals to
act as nodes to route traffic to and from other terminals, enabling the extension of direct links
previously out of range, such as ships beyond the reach of 5G.

On 16 December Inmarsat announced that ORCHESTRA had achieved its first milestone with the
successful activation of a low earth orbit (LEO) satellite payload to test new concepts and system
configurations for ORCHESTRA’s proposed LEO constellation to deliver global communications for
mobility and government customers. By drawing on the unique capabilities of each component, says the
company, ORCHESTRA will enable enhanced connectivity while eliminating such longstanding issues
such as congestion at high demand hot spots, like busy ports, airports, sea canals and flight corridors.

Inmarsat believes that ORCHESTRA could be used for next generation service capabilities, such as air
traffic management for urban air mobility networks, IoT systems, operational connectivity for ferries and
cruise ships and tactical private networks to connect international aid, forces or government agencies in
the field while securely relaying critical data home for analysis.

Satnav signal

Inmarsat is using its Inmarsat-3 F5 satellite to deliver a UK-generated satellite navigation signal.
(Inmarsat)

In addition to launching new satellites, Inmarsat is also finding new uses for ones already in orbit. On 7
December the company announced that it was testing the ability of its Inmarsat-3 F5 satellite to deliver
a UK-generated satellite navigation (satnav) signal, to replace the capabilities lost after Brexit when UK
no longer has access to the European Geostationary Navigation Overlay Service (EGNOS) Safety of Life
services and its involvement in the EU’s Galileo programme. Developed in partnership with the
European Space Agency, Goonhilly Earth Station and GMVNSL, the UK Space Based Augmentation
System (UKSBAS) test project repurposes a transponder from the I-3 F5, launched in 1998, to provide an
overlay signal to augment the US Global Positioning System satellite navigation system. Following the
trials, the first signal-in-space is scheduled to be generated by March 2022.