2017.B.4.4. Observation Geometry Support for CubeSat Missions


Charles Acton (1)

  1. NASA / Caltech-JPL




observation geometry


Space science missions need means to compute a variety of observation geometry parameters used in planning and analyzing science observations as well as in conducting various engineering activities. Space agencies worldwide have often decided to use NASA’s “SPICE” ancillary information system, described here ( https://naif.jpl.nasa.gov ) for this purpose. SPICE includes an open source software library known as the SPICE Toolkit, available in several languages, providing APIs (modules, subroutines, methods) for computing a wide assortment of instrument viewing geometry and related calculations. A SPICE user incorporates a few appropriate SPICE APIs into his/her own application program where geometric parameters such as altitude, latitude/longitude, and lighting angles are needed.

The SPICE system also contains an assortment of underlying data files–called kernels–from which the SPICE Toolkit APIs compute the needed geometry parameters. Some of these kernel files are generic–not specific to any given mission–and are provided by the SPICE developers; examples are planetary ephemerides and target body size, shape and orientation. Other SPICE kernels are mission specific and must be produced by a flight project; examples are spacecraft trajectory and orientation.

The SPICE system components are highly documented. SPICE tutorials and programming lessons are available for self-study and are also taught in a free class offered by the SPICE team once every eighteen months.

A project could acquire all of the SPICE system components and do its own self training in order to fully deploy and operate a SPICE system. However, experience has shown this would be a major undertaking for those not already familiar with SPICE, so it is recommended that projects budget for and make use of persons capable of helping with SPICE training and perhaps even deployment and operation of the kernel production mechanisms.

This talk will provide an overview of the complete SPICE system, including where it is currently being used. The presenter will be available to privately discuss how SPICE might be deployed in support of future CubeSat missions.

The SPICE system has been developed and is maintained by NASA’s Navigation and Ancillary Information Facility at the Jet Propulsion Laboratory in Pasadena, California.

The research described in this publication was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.


  • Will be made available for download after the workshop

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