Astra 4A is a communications satellite owned and operated by SES Astra, launched in 2007 to the Astra 5°E orbital slot providing digital television and radio broadcasts, data, and interactive services to sub-Saharan Africa.
The satellite is physically part of the Sirius 4 satellite, comprising the FSS Africa beam that provides six 36MHz transponders for sub-Saharan Africa. The Sirius 4 satellite also carries a dedicated payload of two transponders for Ka-band services, for future applications such as interactive and contribution services.
TV signals are broadcast with signals levels on the ground (EIRP) of up to 50dBW, receivable with a 60cm dish. The minimum signal level across almost all of mainland sub-Saharan Africa is 44dBW, requiring a 120cm dish.
Although part of a satellite launched and operated by SES Sirius, the commercial responsibility for Astra 4A rests with SES Astra.
The Astra 4A designation was originally given in June 2005 to 33 transponders of the NSS-10 craft (formerly AMC-12) owned by another subsidiary of SES, SES New Skies, and positioned at 37.5°West for broadcast, data, and telecommunications into Africa.