STAR ONE D2

Star One D2 is a Brazilian geostationary communications satellite operating in service of Embratel, one of Brazil's largest telecommunications providers. Catalogued by the United States Space Command under NORAD ID 49055 and internationally designated 2021-069A, the spacecraft was launched on July 29, 2021, and has since taken up a position in geostationary orbit roughly 35,800 kilometres above Earth. It represents a continued investment by Brazilian telecommunications interests in sovereign orbital infrastructure, extending the capacity available to operators serving South America and surrounding regions.

Mission and Purpose

Star One D2 was procured by Embratel to serve communications needs across Brazil and the broader South American region. The Star One brand has long represented Embratel's fleet of geostationary communications satellites, and the D2 vehicle continues that lineage as one of the more capable spacecraft in the series. The satellite is understood to be positioned at 70.0° West longitude, a slot that places it in a favourable arc over the Americas, enabling it to support a wide range of services including broadband internet, direct-to-home television broadcasting, corporate data links, and government communications.

Brazil's geographic scale makes satellite-based communications especially significant. The country encompasses an enormous landmass that includes remote Amazonian communities, agricultural regions far from terrestrial fibre infrastructure, and coastal cities all competing for reliable connectivity. A high-capacity geostationary satellite stationed at 70.0° West can provide national coverage from a single orbital position, reducing dependence on ground-based networks that are both expensive and difficult to maintain across such varied terrain. For Embratel, the D2 spacecraft represents an expansion of the capacity available through this orbital slot, complementing earlier satellites in the Star One family that have served similar functions over preceding decades.

While the satellite catalog entry maintained by INPE — Brazil's National Institute for Space Research, which tracks and registers objects in the national catalog — lists the mission type as not publicly recorded, the operational context surrounding the Star One program makes it evident that communications services form the core purpose of the vehicle. INPE serves as the responsible registering authority for Brazilian space objects, giving the spacecraft its formal standing in both the national and international registers.

Orbit and Tracking

Star One D2 occupies a near-perfect geostationary orbit, one of the most precisely maintained orbital regimes in operational use. As recorded in current tracking data, the spacecraft has an apogee of 35,801 kilometres and a perigee of 35,754 kilometres, producing an orbital eccentricity that is very close to zero. This near-circular profile is characteristic of a well-station-kept geostationary satellite; ground controllers routinely fire small thrusters to counteract the gravitational perturbations from the Moon, Sun, and Earth's equatorial bulge that would otherwise gradually distort the orbit over time.

The orbital inclination is recorded at 0.0 degrees, meaning the satellite tracks almost exactly over the equatorial plane. This is the defining geometric property of a true geostationary orbit: a spacecraft at zero inclination and at the correct altitude will appear to hover motionlessly above a fixed point on Earth's surface when observed from the ground, enabling dish antennas to point at it without tracking motors. The orbital period of 1,435.3 minutes — essentially matching the length of one sidereal day — confirms that the satellite completes exactly one revolution for every rotation of Earth, keeping it synchronised with the planet below.

The COSPAR international designator 2021-069A identifies the spacecraft as the primary payload of the 69th orbital launch of 2021. This designation is assigned by the United Nations Registry of Objects Launched into Outer Space and provides a permanent, unambiguous identifier that distinguishes the satellite from rocket bodies, debris, and co-manifested payloads associated with the same launch. As of the time of writing, Star One D2 remains in orbit with no decay or reentry event recorded.

From a tracking standpoint, geostationary objects present a unique challenge and a unique simplicity. Because they do not drift significantly relative to the Earth's surface, their right ascension and declination as seen from any fixed ground station remain almost constant over time. Satellite-tracking tools such as those provided by LowEarth can display the current position of Star One D2 in real time, though the apparent motion will be negligible compared with objects in low or medium Earth orbit. Observers and engineers tasked with pointing ground terminals will find that the satellite remains reliably at its assigned longitudinal slot barring any station-keeping anomaly.

Design and Operator

Star One D2 was designed and manufactured by Maxar Technologies, a North American aerospace company with deep experience in building high-capacity commercial communications satellites. The spacecraft was constructed on the SSL 1300 satellite bus, a platform developed by Space Systems Loral — now operating under the Maxar Technologies umbrella — that has become one of the most widely deployed satellite platforms in the geostationary arc. The SSL 1300 bus is a flexible, high-power design capable of supporting a wide variety of communications payloads and has been selected by operators across numerous countries and commercial entities over several decades of production.

The satellite carries a launch mass of 6,190 kilograms, placing it firmly in the category of large geostationary communications satellites. A vehicle of this mass typically carries substantial propellant for orbit raising from the transfer orbit delivered by the launch vehicle, as well as for the years of station-keeping manoeuvres required over an operational lifetime. The SSL 1300 bus is designed to accommodate payloads with high electrical power demands, which is consistent with a modern broadband or video distribution mission requiring large numbers of transponders operating simultaneously.

The procuring operator, Embratel, is a Brazilian company historically associated with national long-distance and international telecommunications. It has operated geostationary satellites under the Star One brand since the early 2000s, building a fleet that has progressively expanded in capacity and technological sophistication. INPE, as the national space agency authority, holds the registration for the satellite in Brazil's official space object catalog, reflecting the institutional framework through which Brazil exercises its responsibilities as a launching state under international space law.

Current Status

Star One D2 remains in orbit as an active spacecraft, stationed in the geostationary arc. No reentry or decay event has been recorded in the official catalog data. The satellite's orbital parameters reflect the tightly controlled profile typical of an operational commercial satellite receiving regular station-keeping attention from its ground control team. The apogee and perigee values, separated by only 47 kilometres, indicate a nearly circular orbit consistent with sustained active management rather than the gradual drift that would characterise a satellite no longer under active control.

In the broader context of the geostationary arc over the Americas, the 70.0° West slot is a commercially and strategically significant position. It offers coverage geometry well-suited to Brazil and much of South America, and the presence of a high-mass, high-capacity satellite at that location speaks to the enduring demand for satellite bandwidth across a continent where terrestrial infrastructure coverage remains uneven. Star One D2 joins a heritage of spacecraft that have served this function, and its placement by Embratel reflects both a commercial judgment about the value of orbital capacity and a national interest in maintaining sovereign access to communications infrastructure.

For those monitoring the geostationary belt from a technical or academic standpoint, Star One D2 serves as a representative example of the large commercial communications satellites that constitute the backbone of modern satellite telecommunications. Its relatively high mass, precision orbit, near-zero inclination, and operation by an established regional provider make it a textbook case of the geostationary communications satellite archetype that has defined commercial space operations since the 1960s — now realised with the considerably greater power, capacity, and longevity that modern spacecraft engineering permits.

How to Spot It

Star One D2 is a geostationary satellite and, as such, is not a practical target for casual visual observation. At an altitude of approximately 35,800 kilometres, it is roughly one hundred times farther from Earth's surface than the International Space Station. The satellite does not pass visibly across the sky from any given location; instead, it remains fixed relative to the ground, making it appear as a stationary point rather than a moving object.

Observers using a telescope with accurate pointing may, under good conditions, be able to detect geostationary satellites as faint, essentially non-moving points of light against the stellar background, identifiable chiefly because they do not share the apparent motion of the stars due to Earth's rotation. For Star One D2, this would place it along the equatorial geostationary arc as seen from South American latitudes, at the declination corresponding to a point near 70.0° West longitude above the equator. Amateur astronomers who have successfully imaged geostationary satellites report that long-exposure astrophotography against the star field can reveal these objects as stationary dots while stars trail around them — a reversal of the usual observational geometry. Beyond this specialised technique, the satellite is not visible to the naked eye and does not feature in standard satellite-spotting guides aimed at general audiences.