===============================
Orbit and attitude manipulation
===============================

In ``irfpy.aspera``, the orbit (position and velocity) of spacecraft is supported,
with a help of SPICE (*link here*) and its Python binding, spiceypy (*link here*).
:mod:`irfpy.mexpvat.mexspice` and :mod:`irfpy.vexpvat.vexspice` modules provide
useful functions to obtain the orbit.

The spacecraft attitude and sensor field-of-view is also possible to obtain,
but it is more advanced.

**Checking setup**

One may see the following if the setup is correctly done.

.. code-block:: python

        >>> import spiceypy

If you get no output with this command, SpiceyPy is successfully installed.
If you see import error as below, the installation of SpiceyPy has been failed.

.. code-block:: python

        >>> import spiceypy
        ImportError: No module named 'spiceypy'

In such a case, you can try the following from a shell.

.. code-block:: sh

        % pip install "git+https://github.com/AndrewAnnex/SpiceyPy.git"


.. note::

        Experienced users of SPICE are able to call SPICE functions directly from ipython.
        See the excellent project of Python bindings of SPICE, SpiceyPy, for details.



.. toctree::
   :maxdepth: 1
   :glob:

   tutorial_33?0_*