Gorizont

{{Short description|Russian/Soviet satellites series, launched 1978–2000}}

{{Use British English|date=March 2021}}

{{Use dmy dates|date=March 2021}}

{{Infobox spaceflight

| name = Gorizont

| names_list = Горизонт
Horizon
11F662

| image = The Soviet Union 1991 CPA 6301 stamp (14th standard issue of Soviet Union. 3rd issue. Means of Space Communication. 'Gorizont' communications satellite) 1200dpi.jpg

| image_caption = Gorizont on a 1991 Soviet stamp

| image_size = 300px

| mission_type = Communications

| operator = Russian Satellite Communications Company (RSCC)

| COSPAR_ID =

| SATCAT =

| website =

| mission_duration = 3 years (planned)

| spacecraft = Gorizont

| spacecraft_type =

| spacecraft_bus = KAUR-3

| manufacturer = NPO PM (ISS Reshetnev)

| launch_mass = {{cvt|2110|kg}}

| dry_mass =

| dimensions =

| power =

| launch_date = 1978 - 2000

| launch_rocket = Proton

| launch_site = Baikonur

| launch_contractor = Khrunichev

| entered_service =

| disposal_type =

| deactivated =

| last_contact =

| orbit_reference = Geocentric orbit

| orbit_regime = Geostationary orbit

| orbit_longitude =

| apsis = gee

| trans_band =

| trans_frequency =

| trans_bandwidth =

| trans_capacity =

| trans_coverage = Soviet Union, Russia

| insignia =

| insignia_caption =

| insignia_size = 200px

| programme = Gorizont constellation

| previous_mission =

| next_mission =

}}

Gorizont ({{langx|ru|Горизонт}}, {{lit|horizon}}), GRAU index 11F662, was a series of 35 Russian, previously Soviet, geosynchronous communications satellites launched between 1978 and 2000. The program was started in order to develop a satellite system to relay coverage of the 1980 Olympic Games from Moscow. The first four satellites were originally launched for this sole purpose.{{cite web |last=Wade |first=Mark |title=Gorizont |url=http://www.astronautix.com/craft/gorizont.htm |url-status=dead |archive-url=https://web.archive.org/web/20080617211454/http://www.astronautix.com/craft/gorizont.htm |archive-date=2008-06-17 |access-date=2008-06-29 |publisher=Encyclopedia Astronautica}} Following this, the Gorizont system was integrated into the YeSSS Unified Satellite Communication System, and was used to relay both civilian and military communications. From 1988 onwards, the satellites were also used in support of the Okean program.  

Gorizont satellites were based on the KAUR-3 satellite bus, which provided three-axis stabilisation, and liquid maneuvering engines. The Gorizont satellite constellation was replaced by the Ekspress constellation. The first satellite Gorizont-11L was launched on 19 December 1978 and the last satellite launched was Gorizont No.45L on 6 June 2000.