Daina Bouquin

Supporting Open Space Missions with MetaSat

a metadata toolkit for small satellites


Mechanisms for modeling relationships between the information gathered from contextual sources.

Humphrey, S.D. Multiple Exposures of the Moon: Nine Exposures, daguerreotype, 1849.

Earliest image of the moon.


Was the only image of the moon.


Was a technological innovation that started a scientific revolution.


Now it's art.

Galileo's notes.


Was chicken scratch.


Now the birth of observational astronomy and the origin of scientific method.

Galilei, G. (1610). Osservazioni e calcoli relativi ai Pianeti Medicei.

Meaning is collective agreement about a specific thing at a specific time.


Meaning is not static.

Meaning needs to be
machine actionable

Human-readable metadata is limited

Meaning needs to be
machine actionable

Human-readable metadata is limited

Incomplete example, but you get the idea

MetaSat is a toolkit to help smallsat teams make their metadata more useful


MetaSat has three primary components:

  1. MetaSat Vocabulary

  2. MetaSat Example Files (JSON-LD)

  3. MetaSat Crosswalks

MetaSat Vocabulary

  • Unique concepts that describe spacecraft, missions operations, ground stations, and more.
  • Each concept in the MetaSat Vocabulary has a unique, permanent URI
    • URIs are machine-actionable and support:
      • Search Engine Optimization (SEO)
      • Federated search across platforms via APIs
    • Since each concept has it's own URI, the vocabulary can be used for linked data applications and schemas that use any format of the RDF data model


MetaSat Vocabulary

  • MetaSat's vocabulary is not hierarchical
  • ​MetaSat's vocabulary is flat, but we have grouped concepts into two types of categories that we hope are useful— these gropings should be treated as recommendations
    • Concept Segments - collections that are related to a specific phase of a space mission
      • e.g., Space Segment; Ground Segment
    • Concept Families - collections that are conceptually related
      • e.g., Communications; Propulsion; Thermal Control


MetaSat Example Files (JSON-LD)

  • Example implementations of the MetaSat vocabulary.

  • Our examples are written in JSON-LD

    • JSON-LD is a highly flexible form of RDF that is built to be easily human-writable and machine-actionable.

  • The examples files combine our vocabulary with structure, and give recommendations for how the concepts relate to each other.

Example of a few subsystems from the PICARD mission

MetaSat Crosswalks

  • A crosswalk is a table of equivalencies for converting metadata from one vocabulary into another.

  • Our crosswalks, in combination with our decision to develop JSON-LD examples, will allow MetaSat users to combine different vocabularies into a single document, or convert documents into other RDF syntaxes without losing any information.

Thermal Noise

This example also incorporates concepts from schema.org

Supporters and Early Adoptors

  • Libre Space Foundation— dedicated to supporting open source space technologies; creators of SatNOGS

    • SatNOGS was first to implement MetaSat on their APIs

  • PMPedia—  collaboratively developed by the University of Colorado Boulder Laboratory for Atmospheric Space Physics (LASP) and The Aerospace Corporation.

  • SSRI Knowledge Base— collaboratively developed by Sedaro Technologies and NASA’s Small Spacecraft Systems Virtual Institute with participation from civil, DoD, and commercial space systems providers.

  • The CEOS Database— funded by ESA to provide information on satellites based on an annual survey of all 34 CEOS member agencies.

Who does the work?

We have created some tools, but it is not yet clear

how to best support their use as the mission progresses


It is no one's job to:

  • structure and record this metadata  
  • make any of this information machine-actionable
  • curate and archive mission "artifacts"
    (beyond papers and datasets)


It is also not clear what should be recorded, when, or how.

We want to study the full mission planning and execution process

  • Determine information needed to adequately describe open SmallSat missions; document the required information.

    • What is the prevailing normative interpretation of “open science” in this context? (e.g., What hardware metadata must be available? How should it be made available? Which physical and digital artifacts should be archived?)

    • What major policies influence open science practices in this context?  (e.g., open software policies; UN Convention on Registration of Objects Launched into Outer Space)

  • Define what tools are needed to adequately support information maintenance throughout the SmallSat mission; define relevant non-technical needs.

Learning these things

will help us give smallsat teams

Information Maintainers.


Context is too easily lost, and lessons learned are too valuable to ignore problems with sharing information.


Our goal is to pilot new approaches to

supporting your research.

Supporting Open Space Missions with MetaSat

By Daina Bouquin

Supporting Open Space Missions with MetaSat

Presented to the Center for Astrophysics SmallSat Program. February 8, 2021.

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