RESOURCESAT-2

RESOURCESAT-2 is an Indian Earth observation satellite operated by the Indian Space Research Organisation (ISRO) and catalogued under NORAD ID 37387 with the international designator 2011-015A. Launched on April 20, 2011 (UTC), it continues to orbit Earth in a sun-synchronous orbit, serving as a dedicated land and resource monitoring platform. As the eighteenth remote sensing satellite constructed by ISRO, it carries forward a well-established lineage of Earth observation missions and represents a meaningful step forward in India's domestic capacity for environmental monitoring, agricultural assessment, and land-use analysis.

Mission and Purpose

RESOURCESAT-2 was conceived as a continuity and enhancement mission following the earlier RESOURCESAT-1 spacecraft. Its primary purpose is to collect high-resolution and medium-resolution multispectral imagery of Earth's surface, supporting a wide range of applications including agricultural crop monitoring, forestry assessment, water-body mapping, land-use and land-cover classification, disaster management support, and urban planning. These are not passive or secondary functions — such data feeds directly into national resource management programs, providing policymakers, scientists, and planners with timely and accurate spatial information.

The satellite carries forward the same class of imaging instruments that established RESOURCESAT-1's reputation as a reliable observation platform, while incorporating several improvements in response to user feedback and evolving operational needs. Among the most significant enhancements is an expanded swath width for the LISS-4 imager. Where the original spacecraft's LISS-4 instrument operated with a multispectral swath of approximately 23 kilometres, RESOURCESAT-2 extended that coverage to approximately 70 kilometres, a substantial increase that allows more ground area to be imaged in a single pass without sacrificing the spatial resolution that makes the instrument useful for fine-scale analysis. This change directly addresses one of the practical constraints of high-resolution Earth observation: the inherent tension between resolution and coverage.

Beyond the swath improvement, RESOURCESAT-2 incorporates refinements in its payload electronics, including miniaturisation of key components. Such engineering changes are typical of follow-on missions, where accumulated operational experience points to specific areas where mass savings, power efficiency, or reliability can be improved without altering the fundamental mission character. The result is a satellite that is functionally compatible with its predecessor — ensuring continuity of data products for long-term users — while offering tangibly improved performance in certain key dimensions.

Orbit and Tracking

RESOURCESAT-2 operates in a sun-synchronous orbit (SSO), a type of near-polar orbit in which the satellite's orbital plane maintains a roughly constant angle relative to the Sun throughout the year. This geometry is highly valued for Earth observation missions because it ensures that the satellite passes over any given location at approximately the same local solar time on each revisit. Consistent solar illumination conditions make it much easier to compare images taken weeks or months apart, which is essential for change-detection studies, crop phenology monitoring, and long-term environmental assessments.

According to current orbital data, RESOURCESAT-2 maintains an apogee of 832 kilometres and a perigee of 817 kilometres, placing it in a nearly circular orbit at an altitude of roughly 820–830 kilometres above Earth's surface. The orbital inclination is 98.8 degrees, which is the retrograde tilt characteristic of sun-synchronous orbits — slightly past polar, allowing the slow precession needed to keep pace with Earth's movement around the Sun. The orbital period is 101.2 minutes, meaning the satellite completes approximately 14 full orbits of Earth each day.

This combination of altitude, inclination, and period is well-matched to the requirements of land imaging. At around 820–830 kilometres, the satellite is high enough to achieve useful swath widths and revisit times, but low enough to maintain the spatial resolution needed for the fine-scale applications its instruments are designed to support. The orbit remains stable: RESOURCESAT-2 has not decayed or re-entered and continues to be tracked as an active orbiting object. Its orbital parameters can be followed in real time through NORAD tracking data and are reflected in regularly updated two-line element sets.

Design and Operator

RESOURCESAT-2 was designed, built, and launched by the Indian Space Research Organisation, India's primary civil space agency. ISRO has operated a continuous series of Indian Remote Sensing (IRS) satellites since the 1980s, building up substantial in-house expertise in the design of Earth observation spacecraft and their associated ground infrastructure. RESOURCESAT-2 is part of this lineage, representing the organisation's eighteenth remote sensing satellite and a product of decades of incremental development.

The satellite's manufacturer is not recorded in the publicly available catalog data for this object. ISRO, however, has historically developed its remote sensing platforms largely through its own facilities and workforce, with the UR Rao Satellite Centre (formerly ISAC) in Bengaluru playing a central role in spacecraft integration and testing. The satellite was launched on April 20, 2011 UTC, and placed into its operational orbit by a Polar Satellite Launch Vehicle (PSLV), the workhorse launcher that ISRO has used for the majority of its Earth observation missions. The PSLV's reliable performance record and its ability to deliver payloads precisely into sun-synchronous orbits made it the natural choice for this mission.

The mass of the satellite is not recorded in the current catalog entry. The satellite carries its suite of imaging instruments — most notably the LISS-3 medium-resolution imager, the LISS-4 high-resolution imager, and the AWiFS wide-field sensor — which together provide complementary views of Earth's surface at different spatial scales and swath widths, allowing users to select the appropriate data product for their specific application.

ISRO manages satellite operations from its ground stations in India, with the National Remote Sensing Centre (NRSC) in Hyderabad serving as the primary hub for data reception, processing, archiving, and distribution from Earth observation satellites in the RESOURCESAT series.

Significance and Legacy

Within the context of India's space programme, RESOURCESAT-2 holds a clear place as both a continuation and an improvement upon what came before it. The original RESOURCESAT-1, launched in 2003, proved to be a durable and productive mission, generating substantial quantities of useful data for domestic and international users. By designing RESOURCESAT-2 to be compatible with its predecessor's data products while expanding capabilities where users had identified gaps, ISRO demonstrated a methodical, user-driven approach to mission planning.

The 70-kilometre multispectral swath of the LISS-4 instrument, expanded from the 23-kilometre swath of the earlier satellite, is particularly notable. In practical terms, this means that high-resolution multispectral coverage of a given region can be achieved with fewer passes, reducing the time required to map large areas and increasing the overall utility of the data archive. For agricultural monitoring at national scales, or for rapid assessment of flood extents and wildfire boundaries, this kind of improved area coverage per pass has concrete operational value.

More broadly, RESOURCESAT-2 is part of a larger global infrastructure of land observation satellites that collectively provide the temporal and spatial coverage needed to monitor a changing planet. Its data contributes to efforts coordinated through international frameworks for Earth observation, and its continued operation more than a decade after launch underscores the long design lives achievable by well-built spacecraft in stable sun-synchronous orbits.

ISRO subsequently developed and launched RESOURCESAT-2A in 2016, extending the series further and ensuring continued data availability should either earlier satellite experience technical difficulties. The existence of this follow-on speaks to the recognised importance of the RESOURCESAT data stream for Indian and international users.

How to Spot It

RESOURCESAT-2 orbits at an altitude of approximately 820–830 kilometres in a sun-synchronous orbit, completing a pass overhead roughly every 101.2 minutes. Like most Earth observation satellites at this altitude, it is not among the brightest objects in the night sky, but it is detectable with the naked eye under the right conditions — appearing as a steadily moving point of light, similar in behaviour to other low Earth orbit satellites.

The best opportunities to observe it occur in the hours just after sunset or just before sunrise, when the observer on the ground is in darkness but the satellite, at its orbital altitude, is still illuminated by sunlight. During the middle of the night, when Earth's shadow falls across the orbital altitude, the satellite will not be visible. Clear skies and locations away from significant light pollution improve the chances of a sighting.

Because RESOURCESAT-2 is in a near-polar, sun-synchronous orbit inclined at 98.8 degrees, it passes over a wide range of latitudes and can be observed from most populated areas of Earth given a suitable pass geometry. Up-to-date pass predictions based on current two-line element data are available directly on this site and will give precise times, maximum elevation angles, and compass bearings for any observer location.