ECHOSTAR 21

EchoStar 21 is a geostationary communications satellite operated by EchoStar Corporation, a major American satellite services and technology company. Launched in June 2017 and registered under NORAD catalog identifier 42749, it occupies a near-equatorial orbit approximately 35,800 kilometers above Earth's surface. The satellite was designed to extend mobile broadband connectivity across Europe using S-band spectrum, addressing growing demand for terrestrial network supplementation and wide-area wireless coverage on the continent. It remains in operation as of the time of writing, continuing to serve its communications role from geostationary orbit.

Mission and Purpose

EchoStar 21 was conceived as a dedicated mobile satellite services (MSS) platform for the European market, carrying S-band transponders that operate within the 2 GHz frequency range. This portion of the radio spectrum has long been recognized as well-suited for mobile applications, offering a favorable balance between propagation characteristics and antenna size requirements for ground-based receivers. The practical effect of this configuration is the ability to deliver connectivity to mobile users across a broad geographic footprint — in EchoStar 21's case, spanning Europe as a whole.

The satellite's mission fits into a broader industry effort to use geostationary platforms to supplement terrestrial 3G and 4G mobile networks, particularly in areas where ground-based infrastructure is sparse, economically unviable to deploy, or subject to disruption. By providing a space-based layer of 2 GHz coverage, EchoStar 21 can theoretically extend mobile services to maritime zones, remote rural regions, and cross-border corridors that terrestrial networks do not reliably reach.

EchoStar Corporation, headquartered in the United States, has historically been a provider of both direct-to-home satellite television and broadband services, but EchoStar 21 represents a distinct branch of that portfolio — one focused on infrastructure-level mobile connectivity rather than consumer video delivery. The satellite's specific operational arrangements, including any roaming agreements, spectrum-sharing frameworks, or active service partnerships with European mobile network operators, are not fully detailed in publicly available catalog records.

Orbit and Tracking

EchoStar 21 occupies a geostationary orbit, the class of orbit in which a satellite's orbital period matches Earth's rotation period, causing it to appear essentially stationary when viewed from the ground. This characteristic makes geostationary satellites particularly valuable for communications applications, since ground-based antennas can be fixed in a single direction rather than needing to track a moving object across the sky.

The satellite's tracked orbital parameters confirm its placement in this regime. Its apogee stands at 35,804 km and its perigee at 35,786 km, representing an extremely circular orbit with a difference of only 18 km between its highest and lowest altitudes. The orbital period is 1,436.2 minutes — closely matching the roughly 1,436-minute sidereal rotation period of the Earth, which is the defining characteristic of a true geostationary slot. Its orbital inclination is 1.8°, a slight deviation from the ideal 0° equatorial plane that defines a perfectly stationary geostationary orbit. In practice, this small inclination means EchoStar 21 traces a very slight figure-eight path, known as an analemma, as seen from a fixed point on the ground — an effect imperceptible for most practical communications purposes but observable through precise tracking.

The satellite was assigned the international COSPAR designator 2017-032A, indicating it was the primary payload of the thirty-second orbital launch of 2017. It is cataloged by the United States Space Force's 18th Space Control Squadron within the NORAD system under ID 42749. As a payload in geostationary orbit, EchoStar 21 is tracked as part of the larger population of active and inactive objects in the geostationary belt, a region that is subject to international coordination and management given the finite number of orbital slots it contains.

At a mass of 6,871 kg, EchoStar 21 is a large satellite by any measure, consistent with the category of high-capacity geostationary communications platforms that have been the backbone of commercial satellite services for decades.

Design and Operator

EchoStar 21 was manufactured by Lanteris Space Systems and is based on the SSL 1300 satellite bus, one of the most widely flown commercial satellite platforms in the industry. The SSL 1300 is a flexible, high-power bus that has been used for a diverse range of geostationary missions, valued for its ability to accommodate substantial payload mass and power demands. Its heritage in commercial communications satellites stretches back decades, making it a well-characterized foundation for a mission like EchoStar 21.

The SSL 1300 bus is typically configured to support large arrays of transponders, high-power amplifiers, and the thermal and attitude-control systems needed to maintain stable pointing over a satellite's operational lifetime. For a mission carrying S-band payloads intended for wide-area mobile coverage, the bus's power generation capacity and payload accommodation volume are directly relevant, enabling the kind of high-gain antenna systems and amplifier chains that mobile satellite services require.

The satellite is operated by EchoStar Corporation, an American company with extensive experience managing geostationary assets. Although EchoStar 21 is oriented toward European communications coverage, its ownership and operational control remain with a U.S.-based entity, a common arrangement in the international commercial satellite industry. The specific ground station infrastructure used to command and control EchoStar 21 is not detailed in publicly available catalog data.

EchoStar 21's launch took place on June 7, 2017, lifting off during the evening hours on the Eastern Seaboard of the United States. The satellite was successfully delivered to its intended orbit, where it has remained ever since. No reentry or decay event has been recorded; the spacecraft continues to orbit as of the current catalog update.

Current Status

EchoStar 21's operational and mission status is not formally recorded in the public orbital catalog maintained by LowEarth's reference sources. As of the most recent data, the satellite remains in orbit, and its physical parameters — inclination, period, altitude — are consistent with an object being actively maintained in its geostationary assignment. Satellites that are no longer actively controlled tend to drift in inclination over time due to gravitational perturbations from the Moon and Sun; EchoStar 21's modest 1.8° inclination is not inconsistent with either an actively managed operational satellite or one in the early stages of station-keeping relaxation, and no definitive conclusion can be drawn from orbital data alone.

For operational updates, service announcements, or confirmation of current mission status, EchoStar Corporation's official communications are the appropriate authoritative source. The satellite's trajectory and orbital evolution will continue to be updated in the NORAD catalog as tracking data is collected and processed.

How to Spot It

EchoStar 21 is a geostationary satellite and, as such, presents particular challenges and characteristics for ground-based observers. Because it remains nearly fixed in the sky relative to any given location on Earth, it does not arc across the sky the way low-Earth orbit satellites do. Instead, observers would need to know the precise azimuth and elevation corresponding to EchoStar 21's geostationary slot and look in exactly that direction with appropriate optical equipment.

At geostationary altitudes — approximately 35,800 km — satellites are far too faint to see with the naked eye under most circumstances. A large spacecraft massing nearly 7,000 kg with substantial solar panel arrays may be detectable with a backyard telescope under ideal conditions, particularly when the satellite is illuminated by the Sun and the observer is in darkness. However, casual naked-eye observation is not realistic at this orbital altitude.

The slight orbital inclination of 1.8° means that EchoStar 21 does not remain at a perfectly fixed elevation as seen from a given point; it traces a slow, small loop over the course of each sidereal day. This movement is subtle and would generally not affect casual observation attempts, but it is reflected in the precise tracking data available through the LowEarth platform. For observers with equatorially mounted telescopes or satellite-tracking mounts, the current predicted position can be obtained from the tracking tools associated with this catalog entry, using the NORAD ID 42749 to pull the latest two-line element set for accurate pointing.