SES-5 (EGNOS/PRN 136)

SES-5, cataloged by the United States Space Surveillance Network under NORAD ID 38652 and internationally designated 2012-036A, is a commercial geostationary communications satellite operated by SES S.A., one of the world's largest fixed satellite services providers. Launched in July 2012 and placed into a near-perfectly circular geostationary orbit, the spacecraft has remained in service and continues to orbit Earth today. Among its notable characteristics is its role in supporting the European Geostationary Navigation Overlay Service (EGNOS), a satellite-based augmentation system that enhances the accuracy of GPS signals over the European continent — a function reflected in its alternate designation, SES-5 (EGNOS/PRN 136).

Mission and Purpose

SES-5 was built to serve a dual commercial and navigational purpose, which distinguishes it from many purely telecommunications-focused geostationary platforms. On the commercial side, the satellite provides Ku-band and C-band broadcasting and broadband connectivity services, extending SES's capacity to deliver television programming, data services, and enterprise communications across Europe, Africa, and parts of the Middle East.

Perhaps more publicly significant is its role as a host payload for the European Geostationary Navigation Overlay Service. EGNOS is a joint initiative developed under the auspices of the European Space Agency (ESA), the European Commission, and Eurocontrol, designed to augment standard GPS navigation by transmitting correction signals that improve positional accuracy and provide integrity warnings to aviation users and other safety-critical applications. SES-5 carries an EGNOS transponder assigned the pseudorandom noise code PRN 136, meaning that GNSS receivers across Europe can receive augmentation signals broadcast from the satellite, improving GPS accuracy to levels suitable for precision approaches in civil aviation. This makes SES-5 not merely a commercial asset, but a piece of infrastructure embedded in European safety-of-life navigation systems.

The mission type and current operational status are not recorded in the public satellite catalog for this object, but the satellite's continued presence in a stable geostationary orbit is consistent with active service. SES S.A., headquartered in Luxembourg, manages a large fleet of geostationary and medium Earth orbit satellites, and SES-5 represents one of several spacecraft in that fleet that carry hosted government or institutional payloads alongside commercial transponders — a business model SES has pursued extensively as a means of generating additional revenue from capacity that would otherwise go unused.

Orbit and Tracking

SES-5 occupies a position in the geostationary belt, the ring of orbital slots approximately 35,786 kilometers above the equator where a satellite's orbital period matches the rotation of Earth, causing it to appear stationary relative to a ground observer. This characteristic makes geostationary satellites ideal for broadcasting and communications, as ground-based antennas can point at a fixed location in the sky without requiring active tracking.

The orbital parameters recorded for SES-5 confirm its place in this belt with exceptional precision. Its apogee stands at 35,803 kilometers and its perigee at 35,787 kilometers, yielding a nearly circular orbit with only a 16-kilometer difference between the two extremes — an extremely low eccentricity consistent with a well-maintained operational communications satellite. The orbital inclination is recorded at just 0.1 degrees, meaning the satellite's orbital plane is nearly exactly aligned with Earth's equatorial plane. This tiny residual inclination, rather than a perfect zero, is typical for satellites that have been in service for some time, as north-south stationkeeping maneuvers consume propellant and operators sometimes allow a small drift in inclination to extend spacecraft lifetime.

The orbital period for SES-5 is 1,436.2 minutes, extremely close to one sidereal day, which is precisely the condition required for a true geostationary orbit. These figures, taken together, paint the picture of a satellite operating exactly as designed: parked at altitude, nearly motionless relative to the ground, providing continuous line-of-sight coverage to a fixed service area.

Because SES-5 remains stationary from the perspective of ground observers, it does not appear to move across the sky the way low Earth orbit satellites do. It cannot be readily spotted as a moving point of light during twilight hours the way an International Space Station pass might be observed. Instead, it remains fixed at a particular azimuth and elevation determined by the observer's geographic location. At its designated orbital longitude, it is accessible to appropriately aimed antennas across a wide arc of the Eastern Hemisphere.

Design and Operator

SES-5 was manufactured by Lanteris Space Systems and has a recorded launch mass of 6,086 kilograms, placing it firmly in the class of large, high-capacity geostationary communications satellites. Satellites of this mass category typically carry substantial quantities of onboard propellant to support the stationkeeping maneuvers needed to maintain their orbital position over their operational lifetime, as well as large solar arrays to power multiple transponder payloads.

The satellite was launched on July 8, 2012 (Eastern Daylight Time), with the launch campaign arranged through International Launch Services, a provider that has historically offered Proton rocket launch services for commercial geostationary satellites. ILS's involvement in the launch reflects the commercial geostationary market's international character during that era, when Russian Proton vehicles were a common choice for delivering large communications satellites to geostationary transfer orbit.

SES S.A., the operating entity, is a publicly traded satellite operator incorporated in Luxembourg. The company operates one of the most extensive geostationary satellite fleets in the world and has historically positioned itself as a provider of both direct-to-home broadcasting infrastructure and enterprise connectivity solutions. SES's strategy of hosting third-party payloads — such as the EGNOS transponder aboard SES-5 — has been a recurring element of its business model, allowing institutional partners to access geostationary orbit without bearing the full cost of a dedicated spacecraft.

It is worth noting that the owner country field in the satellite catalog records the owner as SES, reflecting the operator's identity as a multinational corporate entity rather than a nation-state. This is not unusual for commercial satellite operators, whose assets may be licensed in one jurisdiction, launched from another, and serve customers across many others.

Current Status

SES-5 is still in orbit as of the time this record was compiled, and has not undergone a decay or reentry event. Its orbital parameters remain consistent with those of an actively maintained geostationary satellite, with the near-zero inclination and near-circular orbit suggesting that stationkeeping operations are either ongoing or were recently active. A satellite allowed to drift without any north-south stationkeeping would gradually accumulate orbital inclination over the years due to gravitational perturbations from the Moon and Sun; the 0.1-degree inclination recorded here indicates that this accumulation has been kept well in check.

For geostationary satellites, end-of-life disposal typically involves raising the spacecraft into a "graveyard orbit" several hundred kilometers above the geostationary belt, freeing the orbital slot for use by a replacement spacecraft and reducing the risk of debris collision in the operationally valuable geostationary ring. Whether SES-5 has reached or is approaching the end of its design life is not indicated by the publicly available catalog data, and its operational status is listed as unknown in the record.

The satellite's EGNOS role, if still active, represents a continued contribution to the safety of aviation navigation across Europe and neighboring regions. The EGNOS system has been operational for civil aviation use since 2011, and the network of satellites and ground stations supporting it has continued to serve as Europe's primary satellite-based augmentation system. The specific current state of the PRN 136 signal broadcast from SES-5 is beyond what the catalog record confirms, but the satellite's stable orbital position is consistent with continued utility in that role.

Significance in Context

SES-5 is a representative example of the mature commercial geostationary satellite market as it existed in the early 2010s — large, capable spacecraft combining commercial telecommunications transponders with hosted payloads serving public-interest functions. Its dual identity, as both a revenue-generating asset for a major satellite operator and a component of a European safety-of-life navigation infrastructure, reflects the increasing integration of commercial and institutional satellite services that characterized that period.

Its NORAD catalog entry and continuous tracking by the Space Surveillance Network ensure that SES-5 remains part of the global record of orbital objects, contributing to the broader effort to catalog and monitor the population of spacecraft and debris in Earth orbit. For researchers, engineers, and navigation professionals with an interest in the EGNOS architecture or in the operations of large commercial geostationary satellites, SES-5 represents a tangible and trackable node in the infrastructure of modern satellite services.