Massively greater bandwidth. Fully dynamic allocation of coverage and capacity. Significantly quicker to manufacture and launch. These are just a few of the characteristics expected from the next generation of satellites joining the Inmarsat GX constellation. The company announced plans today for the first of the new satellites to join the network in orbit from 2023.
This is about the satellites and the contract that we just signed. But it is also really about GX. It is about what these satellites bring to the GX constellation as an end-to-end network and the maturation of our global mobility offering.– Inmarsat Aviation President Philip Balaam
The three satellites – GX 7, 8 and 9 – will be manufactured by Airbus based on the new OneSat platform, promising a solution that is fully reconfigurable in orbit. Rupert Pearce, CEO of Inmarsat, highlights the “highly flexible capabilities” of the new architecture “which can be deployed very quickly” to support growing demand. Airbus’ Head of Space Systems, Nicolas Chamussy adds, “OneSat is a truly disruptive product, both from a manufacturing, and operational point of view, which allows Airbus to offer our customer a market enabling solution with reduced cost and time to orbit.”
A step-change in technology
Each satellite is expected to deliver more capacity than the total GX constellation in orbit today (i.e. the initial four satellites combined), though the company stopped short of disclosing just how much total bandwidth the new satellites will offer. Philip Balaam, President of Inmarsat’s Aviation division spoke about a shifting rhetoric with respect to satellite technology. Much like conversations about Ka or Ku band are (mostly) avoided today, he is keen to avoid the topic of total capacity to the earth’s surface.
Instead, Balaam’s focus is on capacity to individual aircraft and the agility of the network overall to support growth and shifting market conditions. “The overall capacity numbers are not as meaningful as what we’re going to be delivering to our customers. Instead of saying we’re going to deliver this much capacity to the visible earth there’s going to be a different line of communication as we move forward around what services we can deliver to the aircraft.”
The OneSat platform is a software-defined solution that allows for significant flexibility even after the satellite is in orbit. The GX-5 satellite, for example, will significantly increase capacity on the network, but its beam pattern and capacity is relatively fixed. Once it orbits (expected later this year) its coverage footprint is relatively fixed. The additional capacity is necessary in those regions, but once in place the GX-5 satellite offers minimal flexibility to shift into a new orbital slot or adjust coverage patterns. The new satellites will not only be able to make those adjustments, but will be able to do so in real time on a constant basis throughout their orbital life.
The key word is agility. With the on-board processor and active antennae we will be able to instantaneously create new beams in any shape and size… We’ll be able to track clusters of aircraft. We’ll be able to adapt as routes evolve. The fact that they’re software defined means we can upgrade them as technologies on the ground evolve as well. – Inmarsat Aviation President Philip Balaam
Balaam describes a scenario where capacity can be focused on a hub airport, for example, and then a dedicated beam of bandwidth would follow a handful of aircraft from that hub as they proceed to their destination. Given the heavily banked schedules for many airlines this approach delivers a far more efficient use of the satellite’s capacity and better overall performance to the aircraft. A similar concept is used by some current generation HTS satellites, including Eutelsat 172b, but not to the fully dynamic levels that the OneSat platform offers. Eutelsat’s Quantum satellite, slated for launch later in 2019, promises a fully flexible platform similar to that of the new GX satellites, but with Ku-band rather than Ka-band.
A shift in economics
The goal of delivering capacity just-in-time to the desired geographies is about more than just the flight routes known today. Shrinking the window from contract to launch is critical as operators seek to more closely match real demand rather than predict the future. This next generation of satellites aims to close that gap. Balaam expects the timeline to shrink below 24 months from signature to orbit, a significant improvement. He also points out that the two year window is relatively close to matching lead time from airlines on fitting aircraft fleets or acquiring new planes from manufacturers.
That ability to time the investments to more specific customer demand is key to Inmarsat’s future financial goals. Balaam views the new satellite platform as enabling a far more refined investment profile, one that more closely tracks market and customer requirements. That also allows for a better return on invested capital, something the industry is more focused on today perhaps than in the past.
Balaam declined to comment specifically on the price of the satellites, but suggests they “are a significantly better value” than the prior generations. Moreover, they are intended to remain in orbit longer than the traditional 15 years of a GEO satellite today.
Moreover, they are lighter than the I-5 generation by about half. This allows for multiple satellites to be included in a single launch vehicle, further reducing the cost to deliver the new capacity into orbit. Up to three of the new satellites can be launched together or a smaller (and cheaper) launch vehicle could be used. The company has not finalized launch plans for the new trio but the flexibility is important to the future of the constellation for the coming decades of service.
Seamless coverage integration
Adding new satellites to a constellation can be a tricky task, particularly when a large number of subscribers are already online. The new GX satellites will be fully supported by the modem and antenna technology in service today, according to Balaam. Full backwards compatibility was a critical design requirement for the new satellites.
Similar to how the constellation allows for seamless transition between satellites today, and how the upcoming GX 5 and I-6 satellites will overlay additional capacity into the network, so too will these three new GX satellites. Balaam focused not only on the significant capacity boost but the ability to use the new satellites to best deliver coverage where and when it is needed.