Terabits in space: SES and O3b announce mPOWER constellation

Bring on the terabit satellites! SES and O3b announced the mPOWER constellation today, a commitment to deliver terabit capacity satellites in the 2021. The new service adds seven more satellites to the existing 20 satellite plan (12 in orbit; 8 to launch in the next 2 years) and a potential massive increase to capacity for inflight connectivity systems. These new satellites will operate in the Middle Earth Orbit (MEO) to lower latency, though that positioning does present challenges for aviation applications.

The spec’s announced by SES are impressive. The mPOWER constellation will feature “30,000 fully-shapeable and steerable beams that can be shifted and switched in real time.” The service will cover 80% of the earth’s surface. And the system promises “multiple terabits of capacity globally.” This is a next generation offering, building on the existing O3b technology while taking advantage of improvements in on-board processing to allow for the dynamic resource allocation and increased power availability to deliver more spot beams and higher total throughput.

With the launch of O3b mPOWER, SES is opening a new era of connectivity…We are leveraging the pole position we hold today by relying and building on the strengths of our existing O3b Medium Earth Orbit constellation. We are taking a long-term strategic commitment to further boost our capabilities. – Karim Michael Sabbagh, President and CEO of SES

When it comes to advantages, the idea of a fully flexible spot beam array is hard to beat. Rather than hard-coding a design in today and hoping that it is still applicable 15 years later the system can be adjusted, delivering the right power levels in the right places at the right times. Such technologies are in the early stages today – the Eutelsat 172b satellite takes advantage of such, moving capacity back and forth across the Northern Pacific Ocean as planes cross between Asia and North America each day – but the next generation of that architecture adds significantly more flexibility. The sheer number of beams is also beneficial, as smaller beams mean less contention and better spectrum reuse. But drawbacks come with that architecture, too.

Spot beams are great for one-to-one types of communication that make up most end-user data consumption. They are terribly inefficient, however, for broadcast content distribution. The newer Ku-band HTS systems account for this by overlaying a wide beam on top of all the spots and letting one antenna talk to both systems at the same time. Presumably the O3b mPOWER system aims for similar efficiencies but it is unclear where the wide beam will exist.

Another challenge – particularly when it comes to aircraft using the system – is the need to switch satellites every now and then. The satellite in the MEO orbit moves relative to earth so it eventually passes across the horizon. When that happens the antenna must repoint to another satellite and resume data transfers. The traditional mechanical antennae in use today move slowly enough that such a switch generally means a drop in service, albeit a brief one. Next generation antenna technology should help solve that issue but it is unclear that such will be financially viable on aircraft anytime soon.

The MEO orbit and 80% coverage footprint also leaves a number of flight paths out of range. SES and O3b promise a seamless MEO/GEO ecosystem where the same hardware can switch between the satellites, letting the GEO coverage augment the new MEO constellation, but that technology needs to be developed and implemented still. Concerns about uplink capacity – the ability to get that much data off a satellite at any one time – and other technical challenges also exist. But there’s a pretty good chance most of those can be addressed in the next 3-5 years as these satellites are built and launched.

SES and O3b are not alone in the terabit drive. ViaSat is working on its ViaSat-3 architecture with a trio of satellites each providing a terabit of capacity and as a group blanketing earth, minus the polar regions. That system is in the design phase with launch of the first two predicted for the 2019-2020 timeframe. The third ViaSat-3 satellite, providing coverage in the Pacific, remains uncommitted as of yet.

As for why it is uncommitted, that’s all about money. Theses systems are spectacularly expensive. ViaSat spent north of a half billion dollars for the ViaSat-2 system that just launched earlier this year. SES/O3b have more than $3 billion on the line for upcoming systems launches. A big gamble, but also a huge potential payout in the end.

Never miss another post: Sign up for email alerts and get only the content you want direct to your inbox.

Seth Miller

I'm Seth, also known as the Wandering Aramean. I was bit by the travel bug 30 years ago and there's no sign of a cure. I fly ~200,000 miles annually; these are my stories. You can connect with me on Twitter, Facebook, and LinkedIn.


  1. How will these stack up against the constellations proposed by SpaceX, OneWeb, and Boeing? It’s definitely exciting to think of all the additional bandwidth and service availability that will be possible if even half of these make it to market.

    1. The SpaceX and OneWeb constellations are LEO, not MEO. That means WAY more satellites to build (hundreds or thousands rather than a couple dozen) but also true global coverage and each satellite is much smaller so cheaper to build and cheaper to launch. It also means even more and faster satellite hand-offs and a few other challenges, but nothing impossible to build or implement. More competition and options is usually a good thing, though in this case I do expect at least a couple investors to end up disappointed.

Comments are closed.