Inmarsat-5 and Global Xpress

We are launching the world’s first global Ka-band mobile satellite system, delivering high-speed broadband to compact user terminals at up to 50Mbps.

We call this pioneering network Global Xpress.

Global Xpress will be delivered through our next-generation Inmarsat-5 (I-5) satellites, built by US manufacturer Boeing and based on its powerful 702HP platform.

The first Global Xpress satellite – I-5 F1 – entered commercial service on 1 July 2014, serving Europe, the Middle East, Africa and Asia. The second satellite successfully launched from the Baikonur Cosmodorome in Kazakhstan on 1 February. Following the successful launch of the third satellite in the constellation (I-5 F3), scheduled for late August, Inmarsat will progress towards global commercial service introduction of GX services  by the end of 2015.

Alphasat and the award-winning I-4 series

With the launch of Alphasat in July 2013, Inmarsat became the commercial operator of one of the most technically advanced communications satellites ever flown into space.

The size of a London double-decker bus and with a total mass of more than 6.6 tonnes at launch, Alphasat is the largest European telecommunications satellite ever built.

Alphasat now supplements our ground-breaking Inmarsat-4 (I-4) series, which in 2010 was awarded the Royal Academy of Engineering’s prestigious MacRobert Award for innovation after all three I-4s established the world’s first global 3G network.

The Inmarsat-4 fleet are expected to support our L-band services without the need for replacement until the early-2020s.

The I-3 satellites: workhorses of the L-band fleet

The Inmarsat-3s – the first generation to use spot-beam technology – were launched between April 1996 and February 1998.

All five Inmarsat-3 satellites are currently in service. They were developed by prime contractor Lockheed Martin and payload provider Matra Marconi Space.

With an end-of-life power rating of 2,800W, each I-3 can deliver an EIRP (radiated power) of up to 48dBW, and can dynamically reallocate both RF power and bandwidth among a global beam and five spot beams, allowing greater reuse of the available spectrum.

Each I-3 also carries a navigation transponder designed to enhance the accuracy, availability and integrity of the GPS and Glonass satellite navigation systems.

The Inmarsat-3s are expected to remain in operation, providing communication and safety services in the L-band, until around 2018.


Inmarsat-2: first off the launchpad

Our first wholly owned satellites, the Inmarsat-2s, were built by an international consortium led by British Aerospace. They were launched in 1990-2 and, despite a planned design lifespan of 10 years, our final I-2 satellite continued in active service until December 2014, more than two decades later.

The design of the Inmarsat-2, a three-axis-stabilised spacecraft, was based on the Eurostar platform. Each satellite had a 1.3 tonnes launch mass, reducing to an initial 0.8 tonnes in orbit. Initial power rating was 1,200W.