# SSTL-100 bus
*bus . products*

SSTL microsatellite platform used by AlSat-1 and AlSat-1B for medium-resolution optical Earth observation missions.

## Specifications
- **manufacturer**: surrey-satellite-technology
- **product status**: retired
- **deployment context**: orbital
- **bus**: {"platform_class":"mini"}
- **entity type**: bus
- **last verified date**: 2026-06-26
- **verified by**: operator
- **claim status**: unclaimed
- **provider**: surrey-satellite-technology
- **attributes**: {"kind":"bus","manufacturer":"surrey-satellite-technology","product_status":"retired","deployment_context":"orbital","description":"SSTL microsatellite platform used by AlSat-1 and AlSat-1B for medium-resolution optical Earth observation missions.","bus":"{\"platform_class\":\"mini\"}"}

## Editorial
SSTL-100 is a Surrey Satellite Technology microsatellite platform family represented by AlSat-1 and AlSat-1B. AlSat-1B is based on the SSTL-100 platform, while ALSAT-1 provides DMC heritage as an enhanced microsatellite designed and constructed by SSTL with CNTS.[^sstl-alsat-1][^sstl-alsat-1b] AlSat-1 mass is 90.3 kg and AlSat-1B mass is 100 kg, placing the family in the mini orbital class at the top observed value.[^sstl-alsat-1][^sstl-alsat-1b] Payload fit varied by instance: AlSat-1 carried 32 m multispectral imaging over a 600 km swath, and AlSat-1B hosted 24 m multispectral and 12 m panchromatic imagers.[^sstl-alsat-1][^sstl-alsat-1b]

## Compositional position
- bilsat-1 (missions) --[mission_buses]--> SSTL-100 bus
- nigeriasat-x (missions) --[mission_buses]--> SSTL-100 bus
- nigeriasat-1 (missions) --[mission_buses]--> SSTL-100 bus
- topsat (missions) --[mission_buses]--> SSTL-100 bus
- uk-dmc (missions) --[mission_buses]--> SSTL-100 bus
- uk-dmc-2 (missions) --[mission_buses]--> SSTL-100 bus

## Sources
- [sstl-alsat-1] | ALSAT-1: Launched 2002, SSTL space portfolio | https://www.sstl.co.uk/space-portfolio/launched-missions/2000-2009/alsat-1-launched-2002 | tier=operator-datasheet | accessed=2026-06-26
- [sstl-alsat-1b] | AlSat-1B: Launched 2016, SSTL space portfolio | https://www.sstl.co.uk/space-portfolio/launched-missions/2010-2019/alsat-1b-launched-2016 | tier=operator-datasheet | accessed=2026-06-26

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Source: https://eo-atlas.org/products/bus/sstl-100
Maintainer: SpectraWorks B.V. (CC-BY 4.0)