JCSAT-13

JCSAT-13 is the pre-launch designation for a geostationary communications satellite now better known as JCSAT-4B, operated by the SKY Perfect JSAT Group (JSAT), one of Japan's leading commercial satellite communications providers. Catalogued by NORAD under identifier 38331 and internationally designated 2012-023A, the spacecraft was lofted into orbit on May 15, 2012 (May 14, 2012, at 20:00 Eastern Daylight Time), and it remains in service in geostationary orbit to this day. The satellite represents a continuation of Japan's robust commercial satellite communications infrastructure, providing critical connectivity services across a broad coverage footprint in the Asia-Pacific region.

Mission and Purpose

JCSAT-4B, as it is known operationally, serves the commercial communications market under the management of SKY Perfect JSAT, a company formed through the merger of Japan Satellite Systems and SkyPerfect TV, with JSAT itself tracing its roots to the late 1980s as one of Japan's first private satellite operators. The specific mission profile and payload configuration of this spacecraft are not publicly detailed in the satellite catalog record, and the precise nature of the frequency bands, transponder count, or specific service regions it covers have not been formally confirmed through the tracking data available here. What is well established, however, is that JSAT has historically operated satellites providing Ku-band and C-band services for direct-to-home broadcasting, broadband internet access, and enterprise communications spanning Japan, East Asia, Southeast Asia, and parts of the Pacific.

The satellite was registered under the name JCSAT-13 throughout its development and launch preparation phase, a standard industry practice wherein a satellite carries a sequential fleet designation during manufacturing and pre-launch processing before receiving its operational name upon successful deployment and checkout. Following confirmation of its operational status on orbit, it was renamed JCSAT-4B, indicating its role as a successor or supplementary asset in JSAT's JCSAT-4 series slot. The current operational status and mission health of the spacecraft are not reflected in the public catalog record maintained here.

Orbit and Tracking

JCSAT-13 occupies a geostationary orbit, one of the most strategically important orbital regimes in the entire catalog of artificial Earth satellites. A true geostationary orbit requires a satellite to travel in a nearly circular path at an altitude of roughly 35,786 kilometers directly above the equator, completing one full revolution in a period that matches the Earth's own rotation — approximately 23 hours and 56 minutes of sidereal time. When achieved, this produces the characteristic effect of the satellite appearing stationary relative to a fixed point on the ground, enabling antennas on Earth to point in a fixed direction without the need for active mechanical tracking.

The orbital elements recorded for this object are a textbook illustration of a well-maintained geostationary slot. With an apogee of 35,807 kilometers and a perigee of 35,783 kilometers, the orbit is nearly perfectly circular, with a difference of only 24 kilometers between its highest and lowest points — an eccentricity so small as to be functionally negligible for most practical purposes. The orbital inclination is recorded at exactly 0.0 degrees, confirming that the satellite's orbital plane is aligned with the Earth's equatorial plane to within the precision of current measurements. The orbital period of 1,436.2 minutes — just under 23 hours and 57 minutes — is consistent with geosynchronous motion and confirms that the satellite is maintaining its position relative to the Earth's surface.

Satellites at this altitude are subject to gravitational perturbations from the Moon and Sun, as well as from variations in the Earth's own gravitational field caused by its non-uniform mass distribution. Without periodic correction burns using onboard propulsion, a geostationary satellite's inclination would drift over time, rising by roughly 0.75 degrees per year under the dominant influence of lunar gravity. The fact that JCSAT-13's inclination remains at 0.0 degrees indicates that active north-south station-keeping maneuvers are continuing to maintain the spacecraft within its allocated orbital slot. Similarly, east-west station-keeping is required to maintain the satellite at its designated longitude against longitudinal drift driven by slight ellipticity in the Earth's equatorial shape.

NORAD catalog number 38331 is the unique identifier assigned to this object in the U.S. Space Surveillance Network's catalog, allowing it to be tracked and distinguished from the thousands of other objects — payloads, rocket bodies, and debris — also in orbit. The international designator 2012-023A identifies it as the primary payload (suffix "A") of the 23rd launch of the calendar year 2012.

Design and Operator

JCSAT-4B was built on the A2100 satellite bus, a platform developed by Lockheed Martin that has served as the foundation for numerous commercial geostationary communications satellites since its introduction in the 1990s. The A2100 series was designed to offer a high-capacity, high-reliability architecture with a modular approach to payload integration, making it a competitive choice for commercial operators seeking long-duration service lives, typically exceeding 15 years on orbit. The bus uses a three-axis stabilization system and incorporates deployable solar arrays and a large antenna structure that fold compactly during launch. Detailed specifications such as the spacecraft's launch mass, electric power capacity, and specific payload configuration are not recorded in the public catalog entry for this object.

The satellite's operator, SKY Perfect JSAT, is headquartered in Tokyo and operates one of the largest commercial satellite fleets in the Asia-Pacific region. The company provides services ranging from direct broadcast television to maritime and aeronautical communications, and it maintains a substantial network of ground stations to support its fleet. While JAXA — the Japan Aerospace Exploration Agency — is listed as the associated operator in this catalog's records, SKY Perfect JSAT is the commercial entity responsible for the satellite's day-to-day operation and the provision of services to customers. JAXA's involvement may reflect Japan's broader national space policy framework, under which the agency maintains coordination and oversight roles within the Japanese space sector.

The launch itself took place in May 2012, placing the spacecraft into its intended geostationary transfer orbit from which it subsequently maneuvered to its operational geostationary position using its own apogee kick motor or electric propulsion system — a standard procedure for satellites of this class. The launch provider and launch site are not specified in the catalog record presented here.

Current Status and Significance

As of the time of this article, JCSAT-13 — operationally designated JCSAT-4B — remains in orbit, continuing to contribute to Japan's commercial satellite communications infrastructure. Having been launched in May 2012, the spacecraft has now been on orbit for well over a decade. Satellites built on platforms like the A2100 are typically designed with service lives that can extend to 15 years or beyond, depending on fuel reserves and component health, meaning this satellite could plausibly remain operational for years to come, though its current health and operational status are not publicly reflected in the data available through this catalog.

The JCSAT fleet as a whole has played a significant role in shaping communications connectivity across the Asia-Pacific region over the past three decades. Japan was among the earlier nations to develop a commercial geostationary satellite communications sector, and the JCSAT series has been a consistent backbone of that effort. JCSAT-4B's placement in a geostationary slot above the equator serves users across a wide swath of the Eastern Hemisphere, with coverage geometries that suit the high-density populations and maritime routes of East and Southeast Asia.

From a space situational awareness perspective, a fully operational, station-keeping geostationary payload at precisely 0.0 degrees inclination is among the most predictable and least hazardous categories of orbital objects. It occupies a well-defined and internationally coordinated frequency and orbital slot, managed through the framework of the International Telecommunication Union, which allocates geostationary arc positions to prevent interference between neighboring satellites. As demand for geostationary orbital slots and radio spectrum has intensified over the decades, the careful coordination of assets like JCSAT-4B has become increasingly important to the sustainable use of one of humanity's most commercially valuable orbital regimes.

How to Spot It

JCSAT-13 is not a practical target for casual visual observation. At an altitude of approximately 35,800 kilometers, geostationary satellites are among the most distant artificial objects in Earth orbit and are typically too faint to be seen with the naked eye under most conditions. Even with optical aid such as binoculars or a small telescope, locating a geostationary satellite requires knowing its precise sky position — which, by the nature of a geostationary orbit, is a fixed point on the celestial sphere for a given ground location — and viewing conditions free of light pollution and atmospheric turbidity. Observers in the northern mid-latitudes will find geostationary objects clustered along a low arc above the southern horizon, sitting perfectly still against the background stars. Dedicated amateur astronomers with tracking mounts and CCD imaging equipment have successfully imaged geostationary satellites, but it is not an activity suited to casual stargazing.