It's called a Galactic Key. You get it from Looker, the agent guy... Hopefully you're talking about Veilstone city HQ's "base". Or else I can't help you.
veilstone team galactic base veilstone team galactic base
you can;t without a bikes which you get in the galactic base after you infiltrate the eterna team galactic base.
unlock the doors gating Cyrus
the TM is called Earthquake and you find it in team galactic headquarters, Veilstone City.
there is no underwater galactic hideout, the closest hideout you would get to underwater is the aqua/magma base in ruby and sapphire
in the galactica ware house to the left of the galactica base NO NO YOUR A LIER
Yes, Team Galactic is in Platinum.
we'll technically they have 2 bases but the main base is in cobble stone
battle Cyrus the boss of team galactic in there base in veilstone city.
They're held captive in the team Galactic base in Veilstone City.
Im not answering now, or let more guest's answer, because there is no such thing as team aqua. Villians- Team Rocket Team Galactic
To get into the main Team Galactic base, you must go to Snowpoint City and defeat the gym leader there. Then you must go to Lake Acuity and interact with Galactic Commander Jupiter and your rival. Jupiter will leave the lake area and you can go back to Veilstone City where a Team Galactic grunt will be standing near one of the satellite dishes. Talk with him and he will flee, leaving behind a Galactic Key, which allows you to open locked doors in the Galactic Headquarters.