CARTOSAT-2F

CARTOSAT-2F, cataloged by NORAD under identifier 43111 and internationally designated 2018-004A, is an Indian Earth observation satellite operated by the Indian Space Research Organisation (ISRO). Launched on January 12, 2018 (January 11 in US Eastern time), it was carried into orbit aboard a Polar Satellite Launch Vehicle as part of the PSLV-C40 mission. The satellite occupies a nearly circular sun-synchronous orbit at an altitude of approximately 512 kilometres and represents the eighth member of ISRO's long-running Cartosat-2 Series, a family of remote sensing spacecraft that has become central to India's civilian and governmental mapping infrastructure.

Mission and Purpose

The Cartosat-2 Series was conceived and developed by ISRO to provide high-resolution panchromatic and multispectral imagery of Earth's surface, serving a broad range of applications that include urban planning, infrastructure development, coastal zone monitoring, agricultural assessment, and disaster response. As the eighth satellite in this lineage, CARTOSAT-2F continues the operational philosophy established by its predecessors: maintaining a capable constellation in sun-synchronous orbit that can deliver consistent, revisitable coverage of the Indian subcontinent and other regions of interest.

Although the specific instrument payload and detailed mission parameters of CARTOSAT-2F are not fully enumerated in publicly available catalog records, the Cartosat-2 Series as a whole is associated with sub-meter to low-single-digit meter ground resolution imaging, enabling fine-grained cartographic work that underpins national mapping programs, land records management, and boundary delineation. This level of detail makes satellites in the series valuable not only to civilian planners but also to governmental bodies responsible for territorial administration.

ISRO has historically made Cartosat imagery available through the National Remote Sensing Centre (NRSC), which distributes data products to research institutions, state governments, and international users under established licensing frameworks. CARTOSAT-2F fits into this broader data supply chain, contributing additional capacity and redundancy to the constellation at a time when demand for reliable high-resolution imagery from Indian government sources was growing.

The PSLV-C40 mission on which CARTOSAT-2F flew was itself a notable launch, as it carried a large complement of co-passenger smallsats alongside the primary payload. This rideshare arrangement reflects ISRO's increasing role as a commercial launch provider during this period, using surplus capacity on PSLV missions to deploy third-party satellites from multiple countries while simultaneously advancing India's own space program objectives.

Orbit and Tracking

CARTOSAT-2F operates in a sun-synchronous orbit (SSO), a category of near-polar orbit in which the satellite's orbital plane precesses at a rate that keeps it aligned with the terminator — the boundary between the sunlit and shadowed hemispheres of the Earth. This arrangement means the satellite passes over any given location at approximately the same local solar time on each revisit, a property that is highly advantageous for optical Earth observation because it ensures consistent illumination conditions across image sequences acquired days or weeks apart. Analysts comparing imagery from different dates are therefore not confounded by dramatic changes in shadow angle, making change detection and land-cover monitoring considerably more reliable.

As tracked in the satellite catalog, CARTOSAT-2F maintains an apogee of 512 km and a perigee of 512 km, indicating a very nearly circular orbit with negligible eccentricity. At this altitude, the satellite completes one full revolution around the Earth approximately every 94.7 minutes, which translates to roughly fifteen or sixteen orbits per day. The orbital inclination is recorded at 97.5 degrees, a value slightly beyond 90 degrees that is characteristic of sun-synchronous trajectories — the retrograde component of the inclination is what enables the requisite nodal precession rate to be achieved at this altitude.

The NORAD catalog ID 43111 and the COSPAR international designator 2018-004A are the canonical identifiers used by tracking networks, space situational awareness services, and satellite-monitoring platforms to distinguish this object from the thousands of other cataloged objects in Earth orbit. The designator 2018-004A denotes that CARTOSAT-2F was the primary payload (suffix "A") of the fourth orbital launch of 2018 ("004"), providing a useful timestamp and hierarchy within the international tracking system.

Because the orbit is near-circular and at a moderate low-Earth altitude, the satellite is subject to very gradual atmospheric drag, though at 512 km the residual atmospheric density is low enough that orbital decay proceeds slowly. As of the time this article was prepared, CARTOSAT-2F remains in orbit, with no reentry date recorded in the catalog.

Design and Operator

CARTOSAT-2F was designed, built, and is operated by ISRO, India's primary civil space agency. ISRO, headquartered in Bengaluru, has managed the Cartosat program since the early 2000s and has developed substantial in-house expertise in the design of Earth observation spacecraft, including attitude control systems capable of pointing optical instruments to the precision required for fine-resolution imaging. The specific manufacturer of CARTOSAT-2F is not separately recorded in the catalog, consistent with the pattern of ISRO handling spacecraft development internally through its network of space centres.

The Cartosat-2 Series satellites are generally understood to be three-axis stabilised spacecraft, maintaining a fixed orientation relative to the Earth's surface to allow their imaging instruments to collect coherent scenes rather than blurred streaks. Precise attitude knowledge, typically derived from star trackers and gyroscopes, is essential to achieving the geometric accuracy that makes Cartosat imagery useful for cartographic applications, where positional errors of even a few metres can have meaningful consequences for boundary mapping or infrastructure alignment.

The satellite's mass is not publicly recorded in the available catalog data, so no figure is provided here. Similarly, detailed specifications regarding onboard propulsion, power generation, or data link architecture are not confirmed in the sources underlying this article and are therefore omitted rather than approximated.

ISRO's broader remote sensing program, of which CARTOSAT-2F is one component, includes a range of satellite families addressing different sensing modalities — optical, synthetic aperture radar, hyperspectral, and oceanographic. The Cartosat series focuses on optical imaging optimised for cartography and land monitoring, complementing other ISRO assets that address different spectral ranges or resolutions.

Significance and Status

The launch of CARTOSAT-2F in January 2018 reinforced the depth of ISRO's Cartosat constellation at a point when earlier members of the series had been in service for several years and questions of degradation or capacity shortfalls were relevant operational considerations. By adding an eighth satellite to the series, ISRO extended the expected service lifetime of the overall Cartosat-2 imaging capability and reduced dependency on any single spacecraft.

Within the context of India's space program, the Cartosat series has played a significant role in demonstrating that ISRO could develop, launch, and operate competitive high-resolution Earth observation assets without relying on foreign platforms. The data generated has been applied across multiple sectors of the Indian economy and governance structure, contributing to programs ranging from national topographic mapping to disaster damage assessment following floods and cyclones.

CARTOSAT-2F also arrived at a moment when the global commercial Earth observation market was expanding rapidly, with new private operators deploying large constellations of smallsats capable of very high temporal revisit. Against this backdrop, ISRO's continued investment in the Cartosat series represented a commitment to maintaining sovereign, state-controlled imaging capacity independent of commercial vendors — a strategic consideration for a country of India's size and the complexity of its land administration challenges.

The satellite remains in orbit as of the most recent catalog update reflected in this article. No mission end date or decommissioning announcement is recorded in the publicly available tracking data.

How to Spot It

CARTOSAT-2F orbits at an altitude of 512 km on a sun-synchronous ground track, and like most satellites in this orbital regime it is potentially visible to the naked eye under appropriate conditions. Observers at mid-latitudes, including much of the Indian subcontinent, Europe, and North America, can expect regular passes given the high inclination of 97.5 degrees, which causes the ground track to sweep across a wide band of latitudes on every orbit.

The best viewing opportunities occur during the roughly ninety-minute windows after dusk or before dawn, when the observer on the ground is in darkness but the satellite at 512 km altitude is still illuminated by sunlight. During these passes, CARTOSAT-2F will appear as a steadily moving point of light crossing the sky over the course of a few minutes, similar in appearance to other low-Earth orbit payloads of comparable size. It will not flash or blink in the manner of tumbling rocket bodies or debris, as an operational spacecraft in attitude-controlled mode maintains a stable orientation. The satellite's NORAD ID 43111 can be entered into any standard orbital prediction tool or satellite-tracking application to generate accurate pass predictions for a specific location and date.