Following info comes from Megaranger 2.
Here's the Mega Ship.
Here's an exterior shot of the Dark Fortress with something approaching it.
Here's an interior shot of Doctor Hinelar's Base.
Here's Dark Lord J. This is all you ever saw of him in Megaranger.
Here's another exterior shot of the Dark Fortress.
Here's a shot of the Craterites and the Manta Menance, the "Sphinx Ship" is behind them.
Here's Manta Menace.
Here's Black with his Lunar Lance.
Here's Blue with his Astro Axe.
Here's Yellow with her Star Slinger.
Here's Pink with her Satellite Stunner.
Here are the 5 Galaxy Gliders.
Here's a shot of Red on his Galaxy Glider.  
Here's the Astro Megazord.
Here's the Astro Megazord's Cockpit.