Alphasat I-XL

Alphasat I-XL

ESA - Inmarsat

Spacecraft nº:

Inmarsat spacecraft nº: 13

Also called Inmarsat XL and Inmarsat 4A-F4

Artist′s rendition of the deployed Alphasat I spacecraft (image credit: ESA)

Launched together with: Insat 3D

Prime manufacturer	EADS Astrium, Thales Alenia Space
Platform	Alphabus
Operator	ESA, Inmarsat
Mass at launch	6550 kg
Dry Mass	~3500 kg
Basic shape
Dimension (m)
Equipment
Solar array	2 deployable solar arrays
Stabilization
Propulsion	EAM, SPT-100 plasma thrusters
DC power
Design lifetime	15 yrs

Allocation of Service Module element manufacturing to European companies (image credit: CNES)

Photo of the Alphasat being lowered onto the Arianespace flight adapter in Kourou (image credit: ESA)

Arianespace will use an Ariane 5 ECA rocket, designated VA214, to launch the Alphasat XL and INSAT 3D satellites. Alphasat XL, also called Inmarsat XL, is the first satellite to use the Alphabus platform in a public-private partnership between the European Space Agency, Astrium, Thales Alenia Space and Inmarsat. Alphasat XL will provide mobile communications services to Africa and Europe and test experimental technologies for ESA.
INMARSAT-4A F4, with 12 kilowatts of end-of-life power, will operate a contracted 15 years from 25 degrees east to expand the amount of L-band spectrum Inmarsat has at its disposal with its existing fleet.

Ariane vehicle 569, on flight VA214, placed the Alphasat and Insat 3D satellites in a 224 x 35827 km x 3.5 deg geostationary transfer orbit on Jul 25, 2013. Alphasat is a major joint project between the European Space Agency and the maritime satellite operator Inmarsat. The new Alphabus class spacecraft is intended to demonstrate advanced technologies for ESA, including a laser communications system and radio communications links in Q and V band, while carrying a useful `extended L-band' payload to add to Inmarsat's satellite broadband capacity. The Alphabus propulsion system features is the first flight of the new Astrium/Lampoldshausen 500N EAM (European Apogee Motor), a MON/MMH system with an Isp of about 325s.
By Jul 30, 2103 Alphasat was in a 25608 x 35809 km x 0.3 deg orbit.

Ref.: #7(JR683), #12, #228, #242 - update: 02.07.20