I-5 F3 is powering its way into space

The Inmarsat-5 F3 (I-5 F3) satellite was launched on schedule from Pad 39 at 12:44 BST on 28 August 2015. Watch the Proton M launch vehicle blast off from the Baikonur Cosmodrome in Kazakhstan.

The first three stages of the 58.2 m (191 ft) Proton rocket placed the orbital unit comprising the Breeze M upper stage and the I-5 F3 satellite payload into a sub-orbital trajectory less than 10 minutes after launch.

The Breeze M then performed a series of five burns to advance the orbital unit first to a circular parking orbit, followed by intermediate and transfer orbits, and finally into a supersynchronous transfer orbit.

Separation of I-5 F3 and release into geosynchronous orbit occurred at 04:15 GMT on 29 August.

Once operational, following extensive in-orbit and live service testing, I-5 F3 will deliver Global Xpress services to the Pacific Ocean Region, complementing I-5 F1 coverage in the Indian Ocean Region and I-5 F2 coverage in the Americas and Atlantic Ocean Region.

Together they will power the world’s first globally available, Ka-band, high-speed broadband network connectivity service from a single, trusted operator – whether on land, at sea or in the air.


Inmarsat-5 F1 and F2 launches

The first Global Xpress satellite, I-5 F1, blasted off from the Baikonur Cosmodrome on 8 December 2013 followed by I-5 F2 on 1 February 2015.

Forty eight days and 12 million km (7.5 million miles) after launch, I-5 F1 reached its destination in geosynchronous orbit where it underwent a further four weeks of intensive payload testing before it began powering Global Xpress services on 1 July 2014.

I5-F2 is now in geostationary orbit and is due to arrive into its operational orbital slot shortly.

Inmarsat-5 satellites: the statistics

  • The I-5 body – at 6.98 metres (22.9ft), the height of a double decker bus
  • User beams – 89 Ka-band beams generated by two transmit and two receive apertures
  • Spot beams – six steerable spot beams to direct additional capacity where it is needed
  • Solar arrays – a wingspan of 33.8 metres (111ft)
  • Solar panels – five panels of ultra-triple-junction gallium arsenide solar cells generate 15 kW of power at start of service and 13.8 kW by end of life
  • Station-keeping thrusters – a xenon ion propulsion system (XIPS) handles in-orbit manoeuvring
  • Launch mass – 6,100kg
  • Mission lifespan – 15 years