Payload testing begins as I-5 spacecraft arrives in geosynchronous orbit

29 January 2014: Forty-eight days and 12 million kilometres after its launch from the Baikonur Cosmodrome the Inmarsat-5 F1 satellite has arrived in geosynchronous orbit.

I-5 F1 in flight

The first spacecraft in Inmarsat’s new worldwide Global Xpress (GX) network reached its on-station location at 62.6 degrees East on Sunday, January 26, from where it will provide the pioneering ka-band high-speed broadband service across Europe, Africa and much of Asia.

Before then, it will undergo four weeks of intensive payload testing to prepare the Inmarsat-5 (I-5) F1 to begin the first live testing of the Global Xpress service from the end of February..

Impeccable performance

Throughout the long journey into geosynchronous orbit the spacecraft performed “impeccably”.

Franco Carnevale, Inmarsat-5 Programme Manager, said:  “All systems including plasma propulsion, thermal control, guidance and power systems have performed impeccably.

“Complex mechanical deployments of solar arrays, antennas and radiators have all been accomplished successfully.”

Test station

At the beginning of the week, engineers at Inmarsat’s Satellite Control Centre in London were busy powering up the payload, ready for a team of Inmarsat and Boeing engineers based at the satellite access station (SAS) test station at Nemea, Greece, to conduct extensive tests to ensure all systems have survived the trek into orbit.

Franco explained: “They will be testing the spacecraft’s ability to provide high-level performance connectivity to fixed beams using 50 MHz RF channels, plus very high bandwidths’ channels through six beams, steerable anywhere over the visible Earth.

“They will also be recording detailed measurements of all the transfer functions, including antenna pointing accuracy, receive sensitivity and transmitted power.”

The second and third I-5 spacecraft are in the final stages of testing at the Boeing plant in California, USA.

Global Xpress: www.inmarsat.com