# THEOS-1
*missions*

## Specifications
- **operator**: gistda
- **actual launch**: 2008-10-01
- **platform**: astrosat-500
- **launch vehicle**: dnepr
- **orbit type**: SSO/LEO ~822 km, ~98 deg inclination
- **swath km**: 22
- **entity type**: mission
- **last verified date**: 2026-06-21
- **verified by**: agency-doc
- **claim status**: agency-sourced
- **provider**: gistda
- **attributes**: {"operator":"gistda","actual_launch":"2008-10-01","platform":"astrosat-500","launch_vehicle":"dnepr","orbit_type":"SSO/LEO ~822 km, ~98 deg inclination","swath_km":22}
- **relevance**: in-scope

## Editorial
THEOS-1, also called Thaichote, is Thailand's first national Earth-observation satellite.[^gistda-thaichote-details][^nssdca-theos] It launched on 2008-10-01 on Dnepr from Dombarovskiy/Yasny into Sun-synchronous low Earth orbit at about 822-826 km altitude and about 98 degrees inclination.[^gistda-thaichote-details][^nssdca-theos] The mission uses an AstroSat-500-class spacecraft and carries panchromatic and multispectral optical imaging payloads.[^gistda-thaichote-details][^eoportal-theos] The panchromatic channel provides 2 m imagery over a 22 km swath, while the multispectral channel provides 15 m imagery over a 90 km swath.[^gistda-thaichote-details][^nssdca-theos] Application areas include agriculture, forestry, water, urban planning, disaster response, mapping, and oil-spill monitoring.[^gistda-thaichote-details]

## Compositional position
- THEOS-1 --[mission_payloads]--> theos-1-optical-imager (products)
- THEOS-1 --[mission_buses]--> astrosat-500 (products)
- THEOS-1 --[related]--> dnepr (launch_services)
- THEOS-1 --[related-topic]--> land-cover-change (topics)
- THEOS-1 --[related-topic]--> crop-type (topics)
- THEOS-1 --[related-topic]--> deforestation (topics)
- THEOS-1 --[related-topic]--> disaster-damage-assessment (topics)
- THEOS-1 --[related-topic]--> flooding (topics)
- THEOS-1 --[related-topic]--> urban-change (topics)
- THEOS-1 --[related-topic]--> inland-water (topics)
- THEOS-1 --[related-topic]--> oil-spill (topics)

## Sources
- [gistda-thaichote-details] | GISTDA THEOS satellite details (archived) | https://web.archive.org/web/20160329145712/http://theos.gistda.or.th/index.php/en/about-theos/satellite-detail | tier=agency-doc | accessed=2026-06-21
- [nssdca-theos] | NASA NSSDCA THEOS spacecraft record | https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2008-049A | tier=agency-doc | accessed=2026-06-21
- [eoportal-theos] | THEOS mission, eoPortal | https://www.eoportal.org/satellite-missions/theos | tier=community | accessed=2026-06-21

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Source: https://eo-atlas.org/missions/theos-1
Maintainer: SpectraWorks B.V. (CC-BY 4.0)