Instructions
Use your storage key to open the front door to the Galactic Hideout. Walk along the bottom wall to avoid interacting with the scientist.
Walk up the stairs to enter B1F. Battle the Galactic grunt and continue on to climb the stairs, taking you to 1F.
Walk left to battle the grunt and continue to a set of warp panels.
Use the left warp panel to arrive in another room. Use the warp panel in that room to access stairs, which take you to area 2F.
Walk left to find a warp panel. Use it to access another room with stairs. Take the stairs to find a scientist and another set of stairs.
Walk down the stairs to enter the room where the Galactic key is.
Walk to the left and battle this grunt. Finally, pick the item ball up located on the left side of where the grunt was next to the boxes. It contains the galactic key. Use it to open the shutters on your left, taking you back to Veilstone.