INTELSAT 15 (IS-15)

Intelsat 15 (IS-15) is a commercial geostationary communications satellite built by Orbital Sciences Corporation and operated by Intelsat, one of the world's largest satellite services providers. Cataloged by the United States Space Surveillance Network under NORAD ID 36106 and internationally designated 2009-067A, the spacecraft was launched in late November 2009 and remains operational in geostationary orbit above the Eastern Hemisphere. Weighing approximately 2,550 kg, IS-15 provides Ku-band communications services to customers across a broad geographic swath stretching from the Asia-Pacific region toward the Middle East.

Mission and Purpose

IS-15 is a dedicated communications satellite, carrying a payload of Ku-band transponders that serve both commercial and broadcast customers across its coverage region. The spacecraft hosts 22 active Ku-band transponders, with an additional eight held in reserve as spares — a standard design provision intended to ensure continuity of service should any primary transponder experience degradation over the satellite's operational life.

One notable aspect of IS-15's commercial arrangement is a capacity-sharing agreement with SKY Perfect JSAT Group, a major Japanese satellite operator. Five of the spacecraft's transponders are owned and operated by that company under the designation JCSAT-85, effectively making IS-15 a co-hosted platform serving two distinct operators from a single orbital slot. This type of arrangement is common in the commercial satellite industry, allowing operators to share construction and launch costs while tailoring coverage to their respective customer bases.

Ku-band communications satellites like IS-15 are widely used for direct-to-home television broadcasting, broadband data services, very-small-aperture terminal (VSAT) networks, and government communications links. The Ku-band frequency range — spanning roughly 12 to 18 GHz — offers higher bandwidth than older C-band systems, though it is somewhat more susceptible to signal degradation in heavy rain. This trade-off is generally acceptable for the types of regional fixed services that IS-15 was designed to support.

No additional mission-specific details — such as individual customer contracts or specific coverage footprints — are recorded in publicly available catalogs for this object.

Orbit and Tracking

IS-15 occupies a geostationary orbit at 85° East longitude, a position that places it over the Indian Ocean region and grants it a fixed apparent position relative to the ground below. This stationarity is the defining operational advantage of the geostationary arc: antennas on the ground can be pointed at a fixed elevation and azimuth without any need for mechanical tracking, dramatically simplifying the ground infrastructure required for communications services. From 85° East, the satellite has a line-of-sight footprint spanning a substantial portion of Asia, the Indian subcontinent, the Middle East, and parts of East Africa.

The orbital parameters tracked by LowEarth reflect IS-15's stable geostationary configuration. The satellite's apogee is recorded at 35,805 km and its perigee at 35,784 km, indicating an orbit that is very nearly circular — the difference of roughly 21 km between the two extremes is typical for operational geostationary satellites, which are continuously station-kept by onboard propulsion to maintain their assigned longitude and minimize altitude drift. The orbital inclination is recorded at 0.0°, confirming that the satellite's orbital plane is aligned with the Earth's equatorial plane to within measurement precision. Its orbital period of approximately 1,436.1 minutes — just under 24 hours — matches the Earth's rotation rate, which is precisely what allows the satellite to maintain its fixed apparent position in the sky.

NORAD catalog entry 36106 allows ground stations and tracking services to monitor the satellite's position continuously. Although IS-15 is far too faint and distant to be observed with the naked eye or amateur optical equipment under most conditions, radio and radar tracking by the Space Surveillance Network keeps its orbital elements updated. For those wishing to calculate IS-15's position programmatically, the COSPAR designator 2009-067A identifies it unambiguously in international databases.

Design and Operator

IS-15 was designed and manufactured by Orbital Sciences Corporation on the company's Star-2.4 satellite bus. At the time of IS-15's construction, Orbital Sciences was an established mid-tier spacecraft manufacturer known for producing reliable platforms suited to commercial communications missions, and the Star-2.4 represented one of its larger geostationary bus offerings. The platform is a three-axis stabilized design capable of accommodating substantial communications payloads while providing the power and thermal management needed for a multi-decade operational lifespan in the demanding geostationary environment. Orbital Sciences Corporation has since been acquired by Northrop Grumman, though the satellite itself predates that corporate transition.

The spacecraft was launched from the Baikonur Cosmodrome in Kazakhstan aboard a Zenit-3SLB launch vehicle, lifting off on November 29, 2009 (UTC conversion placing portions of the launch window into November 30 local and UTC time). The Zenit-3SLB is associated with the Sea Launch and Land Launch commercial launch programs, and was a capable vehicle for delivering medium-to-large payloads to geosynchronous transfer orbit. From that initial elliptical transfer orbit, IS-15 would have used its onboard apogee kick motor or equivalent propulsion system to raise itself into the final circular geostationary orbit — a standard procedure for commercial satellites of this class.

Intelsat, the satellite's owner and primary operator, is one of the oldest and most globally extensive commercial satellite operators in existence, tracing its origins to an intergovernmental organization established in the 1960s. Today a privately held company, Intelsat operates a large fleet of geostationary satellites providing services to broadcasters, governments, telecom carriers, and maritime and aviation customers worldwide. IS-15 represents one node in that broader fleet, positioned specifically to serve demand in the Asia-Pacific and Indian Ocean region markets.

Status and Significance

IS-15 is confirmed to still be in orbit as of the most recent catalog update, and there is no publicly recorded decay or reentry date assigned to the object — consistent with an operational or at minimum structurally intact geostationary satellite. Geostationary satellites at the end of their operational lives are typically moved to a slightly higher "graveyard orbit" above the geostationary arc rather than being deorbited, a practice that preserves the valuable orbital slot for the next generation of spacecraft and reduces collision risk in the congested geostationary belt.

The satellite's significance lies primarily in its role as a piece of regional communications infrastructure. The 85° East slot is a commercially valuable position in the geostationary arc, offering coverage to densely populated and economically growing markets across South Asia, Southeast Asia, and the broader Indian Ocean basin. The co-hosted arrangement with SKY Perfect JSAT Group, operating five transponders as JCSAT-85, also illustrates the increasingly multinational and multi-operator character of commercial satellite ventures — a trend that reflects both the high cost of geostationary satellites and the geographic reach of modern media and data markets.

From a technical standpoint, IS-15 exemplifies a generation of mid-size commercial communications satellites that bridged the gap between the large, expensive platforms of the 1990s and the more diversified satellite architectures emerging in the 2010s. The Star-2.4 bus and its 22-transponder Ku-band payload represent a well-proven, commercially pragmatic approach to geostationary communications that prioritizes reliability and a long service life over cutting-edge innovation.

The satellite's mass of 2,550 kg at launch places it firmly in the medium class for geostationary communications spacecraft — substantial enough to carry a meaningful transponder complement and the propellant reserves needed for years of station-keeping, yet compact enough to fit efficiently within the Zenit-3SLB's launch envelope. This class of satellite has historically offered satellite operators a favorable balance between capability and procurement cost.

No current mission status — whether the spacecraft remains commercially active, has been repositioned, or has been placed in storage — is recorded in the publicly available tracking catalog entry for NORAD ID 36106. Observers seeking current operational information would need to consult Intelsat directly or refer to current frequency filings with the International Telecommunication Union.