Upon receiving the Volunteer request, Arienne RHD calmly sat down, and calmly pondered.  

Space warfare.  It was one form of combat she had not done yet and the prospect seemed intriging.  
But, she loved the feeling of the ground beneath her feet as she sprinted after a fleeing target...  
Loved the intensity of staring down a group of armed mercenaries, waiting, daring someone to flinch first...  
Loved the intimate feelings of a death fight with crazy yet skilled murderers...

These things and more are what she loved and did as a bounty hunter for the last 13 years in FAS territory.
She wouldn't have these things in a space fighter, or at least it wouldn't feel the same.

...

But she was Horizon.  It was time to expand.
She spent the rest of the night camping next to a peaceful river, watching the embers of the first sculpture she made flying off into the sky...
Into space...

After tying up loose ends, responsibilities, and a few more bounties for old times sake, 6 months before the departure date, Arienne returned to her Horizon homeworld and reunited with her father.  She spent the 6 months spending quality time with him, catching up with him and with old friends, and downloading general knowledge concerning military structure, procedure and protocol.

1 hour before departure time, Arienne arrives to an empty gate and mingles far away, but close enough to see when anyone shows up.
She probably didn't need to do this, but scoping out the location and the people involved was a habit she found useful as a bounty hunter, and wasn't about to drop anytime soon.  She wanted study the people she would work with for the foreseeable future.  To size them up.

She calmly pulls up her hood, calmly turns on some tehcno in her head, and calmly waits...