.. _scenarioSpiceSpacecraft:

scenarioSpiceSpacecraft
=======================

.. raw:: html

    <iframe width="560" height="315" src="https://www.youtube.com/embed/Fux_UsZ5FR0" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Overview
--------

Demonstrates how to use :ref:`spiceInterface` to load a Spice kernel with the Hubble orbital
information and use the corresponding :ref:`transRefMsgPayload` output message
to specify the spacecraft motion.  With this approach the spacecraft attitude is still
dynamic and can achieve the same inertial pointing goal as setup in
:ref:`scenarioAttitudeFeedback`.

The script is found in the folder ``xmera/examples`` and executed by using::

      python3 scenarioSpiceSpacecraft.py

The simulation layout is
shown in the following illustration.  Note that here the ``spiceInterface`` module
must be executed prior to :ref:`spacecraft` as the
:ref:`transRefMsgPayload` input message must be properly setup before initializing
the spacecraft module which reads this in during ``reset()``.

.. image:: /_images/static/test_scenarioSpiceSpacecraft.svg
   :align: center


When the simulation completes 2 plots are shown for the MRP attitude tracking error history,
as well as the Hubble inertial orbital coordinates with respect to the Earth.

Illustration of Simulation Results
----------------------------------

::

    show_plots = True

.. image:: /_images/Scenarios/scenarioSpiceSpacecraft1.svg
   :align: center

.. image:: /_images/Scenarios/scenarioSpiceSpacecraft2.svg
   :align: center