Galaxy 18

{{Short description|Geosynchronous communications satellite}}

{{Infobox spaceflight

| name = Galaxy 18

| image =

| image_caption =

| mission_type =

| operator = Intelsat

| website =

| COSPAR_ID =

| SATCAT =

| mission_duration = 15 years

| spacecraft_bus = LS-1300

| manufacturer = Space Systems/Loral

| dry_mass =

| launch_mass = {{convert|4642|kg|lb}}

| power =

| launch_date = {{start-date|May 21, 2008, 09:43:22|timezone=yes}} UTC

| launch_rocket = Zenit-3SL

| launch_site = Odyssey

| launch_contractor = Sea Launch

| entered_service =

| disposal_type =

| deactivated =

| orbit_epoch =

| orbit_reference = Geocentric

| orbit_regime = Geostationary

| orbit_periapsis =

| orbit_apoapsis =

| orbit_inclination =

| orbit_period =

| orbit_longitude = 123° West ({{Coord|0|-123|display=inline,title}})

| orbit_slot =

| apsis = gee

| trans_band = 24 IEEE C band
24 IEEE K_u band

| trans_frequency =

| trans_bandwidth =

| trans_capacity =

| trans_coverage = United States, Canada, Mexico

| trans_TWTA =

| trans_EIRP =

| trans_HPBW =

}}

Galaxy 18 is a Space Systems/Loral (SS/L) 1300-series hybrid communications satellite owned by Intelsat and located in geosynchronous orbit at 123° W longitude, serving the continental United States, Alaska, Hawaii, Mexico, and Canada with 24 C band, and 24 K_u band transponders. Galaxy 18 replaced Galaxy 10R near the end of its design life.[https://web.archive.org/web/20080517182823/http://www.intelsat.com/network/satellite/scheduled-launch.asp Intelsat Satellite Launch Schedule]

Galaxy 18 was launched on May 21, 2008. The launch took place successfully at 09:43 GMT.{{cite web|url=http://www.sea-launch.com/news_releases/nr_080521.html |title=Sea Launch Successfully Delivers Galaxy 18 to Orbit |publisher=Sea Launch |url-status=dead |archive-url=https://web.archive.org/web/20080531014715/http://www.sea-launch.com/news_releases/nr_080521.html |archive-date=May 31, 2008 }}