A Geo-synchronous Earth-Orbit side-by-side dual-launch spacecraft arrangement, comprising: a fairing having a diameter between 4 and 6 meters (m); a dual-launch adaptor (515, 1215) comprising a first spacecraft support, a second spacecraft support, and a launch interface configured to interface to a launch vehicle; a first GEO spacecraft (505, 1205, 1305, 1605, 1705) mounted at the first spacecraft support of the dual-launch adaptor (515, 1215) by a first core cylinder structure substantially enclosed by a bus structure of the first GEO spacecraft (505, 1205, 1305, 1605, 1705), wherein the first GEO spacecraft (505, 1205, 1305, 1605, 1705)comprises: a first payload component mounted on a first side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705); and a second payload component mounted on a second side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705), wherein the second side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705) is opposite the first side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705); and a second GEO spacecraft (510, 1210, 1310, 1610, 1710) mounted at the second spacecraft support of the dual-launch adaptor (515, 1215) by a second core cylinder structure substantially enclosed by a bus structure of the second GEO spacecraft (510, 1210, 1310, 1610, 1710), wherein the second GEO spacecraft (510, 1210, 1310, 1610, 1710) comprises a third payload component mounted on a first side of the second spacecraft (510, 1210, 1310, 1610, 1710), wherein each of the first (505, 1205, 1305, 1605, 1705) and second GEO spacecraft (510, 1210, 1310, 1610, 1710) has an aspect ratio within a range from 0.55 to 0.8, the aspect ratio being a ratio of a size of a corresponding spacecraft and its payloads along a first lateral dimension and a size of the corresponding spacecraft and its payloads along a second lateral dimension, wherein the first and second lateral dimensions are perpendicular to each other and each of the first and second lateral dimensions is perpendicular to, and smaller than, a height of the corresponding spacecraft, wherein the first GEO spacecraft (505, 1205, 1305, 1605, 1705) and the second GEO spacecraft (510, 1210, 1310, 1610, 1710) are arranged side by side on the dual-launch adapter (515, 1215) and within the fairing, and wherein a maximum number of spacecraft contained within the fairing is two. a fairing having a diameter between 4 and 6 meters (m); a dual-launch adaptor (515, 1215) comprising a first spacecraft support, a second spacecraft support, and a launch interface configured to interface to a launch vehicle; a first GEO spacecraft (505, 1205, 1305, 1605, 1705) mounted at the first spacecraft support of the dual-launch adaptor (515, 1215) by a first core cylinder structure substantially enclosed by a bus structure of the first GEO spacecraft (505, 1205, 1305, 1605, 1705), wherein the first GEO spacecraft (505, 1205, 1305, 1605, 1705)comprises: a first payload component mounted on a first side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705); and a second payload component mounted on a second side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705), wherein the second side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705) is opposite the first side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705); and a first payload component mounted on a first side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705); and a second payload component mounted on a second side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705), wherein the second side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705) is opposite the first side of the first GEO spacecraft (505, 1205, 1305, 1605, 1705); and a second GEO spacecraft (510, 1210, 1310, 1610, 1710) mounted at the second spacecraft support of the dual-launch adaptor (515, 1215) by a second core cylinder structure substantially enclosed by a bus structure of the second GEO spacecraft (510, 1210, 1310, 1610, 1710), wherein the second GEO spacecraft (510, 1210, 1310, 1610, 1710) comprises a third payload component mounted on a first side of the second spacecraft (510, 1210, 1310, 1610, 1710), wherein each of the first (505, 1205, 1305, 1605, 1705) and second GEO spacecraft (510, 1210, 1310, 1610, 1710) has an aspect ratio within a range from 0.55 to 0.8, the aspect ratio being a ratio of a size of a corresponding spacecraft and its payloads along a first lateral dimension and a size of the corresponding spacecraft and its payloads along a second lateral dimension, wherein the first and second lateral dimensions are perpendicular to each other and each of the first and second lateral dimensions is perpendicular to, and smaller than, a height of the corresponding spacecraft, wherein the first GEO spacecraft (505, 1205, 1305, 1605, 1705) and the second GEO spacecraft (510, 1210, 1310, 1610, 1710) are arranged side by side on the dual-launch adapter (515, 1215) and within the fairing, and wherein a maximum number of spacecraft contained within the fairing is two.