HYSIS

HYSIS (also catalogued under the designation HysIS) is an Earth observation satellite operated by the Indian Space Research Organisation (ISRO) and registered under NORAD catalog ID 43719 and international designator 2018-096A. Launched on 28 November 2018, the spacecraft was placed into a sun-synchronous orbit from which it gathers hyperspectral imagery of Earth's surface. As of the time of writing, the satellite remains operational in orbit, continuing to serve India's civilian and strategic remote sensing requirements.

Mission and Purpose

HysIS was developed to provide India with an independent hyperspectral imaging capability — a technology that goes considerably further than conventional multispectral satellites by capturing data across hundreds of narrow, contiguous bands of the electromagnetic spectrum simultaneously. Where a standard optical satellite might record a handful of broad colour channels, a hyperspectral instrument records fine spectral detail that allows analysts to distinguish between materials, vegetation types, and surface compositions that would otherwise appear identical in ordinary imagery.

This depth of spectral information underpins a broad range of applications that are particularly relevant to a country of India's geographic and demographic scale. In agriculture, hyperspectral data can be used to monitor crop health, identify plant stress before it becomes visible to the naked eye, map soil composition, and assess irrigation patterns across large cultivated areas. For forestry management, the technology offers the ability to distinguish tree species, track deforestation, and monitor ecosystem health in dense or remote woodland regions that are difficult to survey on the ground.

Beyond land cover, HysIS was designed with India's varied coastal geography and inland water systems in mind. Hyperspectral sensors can detect subtle changes in water quality, sediment load, algal content, and pollution — data that is valuable for managing ports, estuaries, delta regions, and freshwater bodies such as rivers and lakes. India's long coastline and its extensive river networks, including the Ganges and Brahmaputra systems, represent precisely the kind of complex, dynamic environments for which this imaging approach is well suited.

The satellite's data is not restricted to civilian scientific or resource-management purposes. India's defence establishment also has access to HysIS imagery, reflecting the dual-use nature of high-resolution Earth observation data. Terrain analysis, camouflage detection, and the monitoring of infrastructure and border regions are among the kinds of tasks for which hyperspectral data has established military utility.

Orbit and Tracking

HysIS orbits Earth 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 Sun throughout the year. The practical consequence of this geometry is that the satellite crosses any given point on Earth's surface at approximately the same local solar time on each pass. Consistent solar illumination is important for Earth observation work because it minimises the variation in shadows and lighting conditions between images taken on different dates, making it far easier to compare scenes and detect genuine changes on the ground over time.

The satellite's orbital parameters are well characterised. HysIS maintains an apogee of 639 kilometres and a perigee of 636 kilometres, making it a very nearly circular orbit at an altitude of approximately 637–638 kilometres above Earth's surface. The orbital inclination is 98.0 degrees, consistent with sun-synchronous geometry at that altitude, and the spacecraft completes one full orbit in approximately 97.3 minutes — meaning it circles the globe roughly 14 to 15 times per day.

At this altitude, HysIS sits well within the commonly defined boundary of low Earth orbit (LEO), which is generally considered to extend from roughly 200 kilometres to around 2,000 kilometres altitude. The orbit is stable, and no reentry or decay date has been recorded in the public catalog, indicating the satellite remains active and has not experienced significant orbital degradation.

Observers tracking HysIS through the NORAD catalog can do so using identifier 43719. The international COSPAR designator 2018-096A places the satellite as the primary payload of the 96th orbital launch of 2018 — a detail that helps situate its launch within the broader cadence of global space activity that year.

Design and Operator

HysIS was built for and is operated by the Indian Space Research Organisation, the government agency responsible for India's civilian space programme. ISRO was established in 1969 and has grown over subsequent decades into one of the world's most active and cost-effective space agencies, with a strong track record in remote sensing, communications satellites, and planetary exploration. Its remote sensing programme in particular has produced a long lineage of Earth observation satellites — including the IRS (Indian Remote Sensing) series — that have made India a significant provider of satellite imagery both domestically and internationally.

The manufacturer of HysIS is not publicly recorded in the satellite catalog, and specific details about the spacecraft's structural configuration, power systems, or instrument specifications are not confirmed in the available technical record and will not be speculated upon here. The satellite's mass is similarly not listed in the catalog data. What is established is that the mission was launched on 28 November 2018, and that the satellite was placed successfully into its intended sun-synchronous orbit.

HysIS flew as the primary payload on an ISRO Polar Satellite Launch Vehicle (PSLV) mission, a workhorse rocket that ISRO has used for the great majority of its Earth observation satellite deployments. The PSLV's ability to reliably deliver payloads into sun-synchronous orbits has made it the preferred vehicle for remote sensing missions of this kind. On the same launch, a number of international co-passenger small satellites were also deployed, a common commercial arrangement for PSLV flights.

Significance and Current Status

HysIS represents a meaningful step in India's progression toward full-spectrum Earth observation capability. While India had long operated optical and synthetic aperture radar satellites, the development of a domestic hyperspectral platform added a qualitatively different type of observational data to ISRO's portfolio. Countries and space agencies with hyperspectral satellite capability remain a relatively small group globally, and the successful deployment of HysIS placed India among them.

The civilian applications of the data — in agriculture, water resource monitoring, land use mapping, and coastal zone management — have direct relevance to policy and planning in a country where the livelihoods of hundreds of millions of people depend on agricultural productivity and access to freshwater. The capacity to monitor these systems from orbit, at regular intervals and with high spectral fidelity, provides a tool for evidence-based resource management that would be difficult or impossible to replicate through ground surveys alone.

The strategic dimension of the satellite's mission also reflects a broader pattern in ISRO's programme, which has increasingly integrated national security considerations alongside scientific and developmental goals. Access to indigenous hyperspectral imagery reduces India's dependence on foreign sources for sensitive geospatial intelligence and gives defence planners an additional layer of situational awareness.

As of current catalog records, HysIS remains in orbit with no reentry date recorded, suggesting the spacecraft continues to function within its operational envelope. The satellite's near-circular orbit at roughly 637 kilometres altitude is inherently stable over medium timescales, which is consistent with continued operations. The mission's precise operational status — including whether its instruments remain fully functional — is not confirmed in the public record, and no claims about its current health are made here beyond what the orbital data establishes.

How to Spot It

HysIS orbits at an altitude of approximately 637 kilometres in a sun-synchronous, near-polar orbit, which means it passes over a wide range of latitudes — including most populated parts of Earth — multiple times each day. With an orbital period of 97.3 minutes and an inclination of 98.0 degrees, the satellite traces a ground track that shifts westward with each successive pass, gradually covering the entire globe over the course of several days.

Whether HysIS is visible to the naked eye depends on its size, surface reflectivity, and the observing conditions at any given time. Earth observation satellites at this altitude are sometimes visible as steady, moderately bright moving points of light during the twilight hours — shortly after sunset or before sunrise — when the satellite is still illuminated by sunlight while the observer on the ground is in shadow. The best opportunities arise when a pass takes the satellite to a high elevation angle above the horizon, maximising the apparent brightness and the time it remains in view.

Precise pass prediction tools, including those available on this site using the NORAD ID 43719, will provide the most accurate visibility windows for any given observer location. Times, elevations, and azimuth directions vary considerably depending on where you are on the ground and the current state of the satellite's orbit. Using up-to-date two-line element (TLE) data will yield the most reliable predictions for spotting HysIS on any given evening or morning.