ALSAT-1B

ALSAT-1B is an Algerian Earth-observation satellite launched on 25 September 2016 and operated by the Agence Spatiale Algerienne (ASAL), the country's national space agency. Built by Surrey Satellite Technology Ltd (SSTL) in the United Kingdom, it carries an optical imaging payload designed to support land-use monitoring, agricultural assessment, and disaster response across Algeria and the broader region. Catalogued by the United States Space Command under NORAD ID 41785 and internationally designated 2016-059C, the spacecraft remains active in a sun-synchronous low Earth orbit as of the time of writing.

Mission and Purpose

The primary purpose of ALSAT-1B is to provide Algeria with a sovereign remote-sensing capability oriented toward practical civilian applications. The satellite's imaging system is equipped with a panchromatic channel delivering ground resolution of 12 metres and a multispectral camera operating at 24-metre resolution, giving operators the ability to distinguish broad land-cover categories while also resolving finer surface features useful for agricultural mapping and crop monitoring.

Agricultural surveillance is among the most consequential uses for a country of Algeria's geographic scale and climatic diversity. The nation spans environments ranging from the fertile coastal strip along the Mediterranean to the vast, largely arid Saharan interior. Reliable, repeated satellite coverage allows government agencies and agricultural ministries to track seasonal vegetation changes, assess drought stress, monitor irrigation patterns, and estimate harvest prospects without depending entirely on foreign data providers.

Disaster monitoring is the satellite's other major stated function. North Africa is periodically affected by wildfires, flooding, and desertification dynamics, and rapid satellite revisit can help emergency managers identify affected zones, prioritise relief efforts, and assess infrastructure damage in the aftermath of natural events. Having national control over tasking and data downlink is a practical advantage in time-sensitive situations, since it removes reliance on international service agreements that might impose delays.

The contract for the ALSAT-1B mission was formalised in July 2014, with Surrey Satellite Technology serving as the prime contractor. The spacecraft was launched roughly two years later, a timeline consistent with the relatively streamlined development cycles characteristic of the small-satellite industry.

Orbit and Tracking

ALSAT-1B occupies a sun-synchronous orbit (SSO), a class of near-polar orbit in which the orbital plane precesses at a rate that keeps it at a nearly constant angle relative to the Sun. This means the satellite crosses any given latitude at approximately the same local solar time on every pass, ensuring that successive images of the same area are acquired under consistent illumination conditions. Consistent lighting geometry is particularly valuable for change-detection workflows, where analysts compare images from different dates to identify land-cover transitions or damage signatures.

The spacecraft's current orbital parameters place its apogee at 664 kilometres and its perigee at 653 kilometres above Earth's surface, a difference of only 11 kilometres that indicates a near-circular orbit. The inclination is 97.8°, which is the slightly retrograde tilt required for sun-synchronous precession at this altitude. The orbital period is approximately 97.7 minutes, meaning ALSAT-1B completes roughly 14 to 15 full revolutions around Earth each day.

At this altitude, atmospheric drag is low enough that orbital decay proceeds very slowly, and the satellite remains in orbit more than eight years after its launch with no reentry date currently projected in the tracking catalog. The orbit is also well below the geostationary belt at roughly 35,786 kilometres, keeping the spacecraft within the category of low Earth orbit objects while still high enough to observe wide swaths of terrain on each pass.

For satellite trackers, ALSAT-1B is catalogued as object 41785 in the NORAD system, which provides the authoritative two-line element sets used to compute its current position and predict future passes.

Design and Operator

ALSAT-1B was manufactured by Surrey Satellite Technology Ltd, a British company spun out of the University of Surrey and widely regarded as a pioneer in the small-satellite industry. The spacecraft is based on the SSTL-100 satellite bus, a platform designed for Earth-observation missions in the 100-kilogram class. ALSAT-1B's launch mass is 103 kilograms, placing it squarely within the category of small satellites — a class that has grown enormously in both number and capability over the past two decades.

The SSTL-100 bus is a modular design that allows different payload packages to be integrated depending on the mission requirement. For ALSAT-1B, the payload consists of the optical imaging instruments described above. The combination of panchromatic and multispectral channels is a standard approach in Earth observation, allowing data users to produce pan-sharpened imagery by merging the higher-resolution grayscale data with the lower-resolution colour information to yield composite images that are both detailed and spectrally informative.

The operator, ASAL, was established in 2002 and has progressively built up Algeria's space infrastructure over the following decades. ALSAT-1B is part of a broader national remote-sensing programme that has included earlier satellites, and the agency has used international partnerships with experienced manufacturers such as SSTL to develop domestic expertise while ensuring reliable mission outcomes. Algeria's interest in maintaining its own Earth-observation assets reflects a wider trend among middle-income countries seeking to reduce dependence on foreign imagery providers and to develop the technical workforce needed for a domestic space sector.

Ground operations for the satellite are managed through Algerian facilities, allowing national authorities to task the imaging system, receive downlinked data, and process and distribute imagery according to domestic priorities. This operational autonomy is a core rationale for investing in a nationally owned satellite rather than purchasing imagery commercially.

Current Status and Significance

ALSAT-1B remains in orbit and, based on catalog data, continues to occupy the near-circular sun-synchronous orbit in which it was originally placed. No decay or reentry date is recorded, and the satellite's orbital altitude is consistent with an operational lifetime of many years before atmospheric drag becomes a meaningful factor. Whether the spacecraft's onboard systems remain fully functional is not publicly recorded in the available catalog data.

The satellite's broader significance lies in what it represents for Algeria's space programme and for the wider pattern of developing-nation investment in sovereign space assets. The 2010s saw a notable expansion in the number of countries operating their own remote-sensing satellites, driven by falling launch costs, the availability of capable small-satellite platforms from commercial manufacturers, and a growing recognition of the strategic value of independent Earth-observation capability. ALSAT-1B fits squarely within this trend.

For agricultural nations in particular, the combination of panchromatic and multispectral imaging at the resolutions this satellite provides is suited to a range of monitoring tasks that previously required either expensive high-resolution commercial imagery or dependence on larger international programs. While the 12-metre and 24-metre resolutions are modest by the standards of the highest-performing commercial or governmental reconnaissance systems, they are well matched to landscape-scale applications such as identifying irrigated versus rain-fed cropland, tracking vegetation phenology across seasons, or mapping the perimeter of a wildfire burn scar.

ALSAT-1B was launched alongside other spacecraft on the same mission, as indicated by the "C" suffix in its international designator 2016-059C, which denotes the third catalogued object from the 2016-059 launch event. This kind of rideshare arrangement is common for small satellites, allowing multiple payloads to share launch vehicle costs.

How to Spot It

ALSAT-1B is a small satellite with a mass of 103 kilograms, and at its orbital altitude of roughly 653 to 664 kilometres it is not among the brightest objects in the night sky. Unlike large structures such as the International Space Station or certain rocket bodies that can reach naked-eye prominence, small Earth-observation platforms in this size class are typically faint and may require optical aid or careful observation under dark skies to detect visually.

That said, satellites in sun-synchronous orbits at this altitude do pass overhead regularly and can catch sunlight during the twilight hours before dawn or after dusk when the ground observer is in darkness but the satellite is still illuminated. The characteristic steady, non-blinking motion of a satellite crossing the sky distinguishes it from aircraft. Predictions for visible passes at any given location can be generated from two-line element data using the NORAD catalog number 41785, which is the identifier that links ALSAT-1B to the tracking infrastructure maintained by the United States Space Command and distributed through services used by the amateur satellite-observing community.