The Gundam franchise shouldn't need too much of an introduction: The grand-daddy of the 'Real Robot' mech anime sub-genre, it spawned a whole slew of imitators, as well as a huge empire of merchandise, sequels, side-quels, prequels and alternate universes. 
The major characteristics of a Gundam series are the focus on giant robot combat in space and on earth in a near-ish future setting, against a backdrop of emotional and personal drama, often focused on the idea that war is hell, and that no-one who goes through it comes out all right, and that everyone is someone's villain or hero. All things that have gone on to define the mecha anime genre over the years that have followed. 

My particular favourite Gundam setting is the Universal Century, as I like its' level of technology, continuity, and the general 'feel' it has compared to some of the less 'grounded' (comparatively speaking; we're still dealing with giant robots here) parallel continuities. However, for the RP I'd like to run, I'll probably eject continuity after a certain point to avoid getting caught up in things, or at least not be beholden to it too strictly, so that we can run our own story. 

The RP will follow a small group of Earth Federation mobile suit pilots on a ship outside of the regular area seen in the show, perhaps in the Asteroid belt, carrying out various missions and patrols against Zeon remnants or other hostile forces in support of asteroid mining colonies and resources. Players will be able to pick their own mobile suits (from within a certain part of the timeline, and Universal Century only to avoid things being too overpowered or mixed up), and there won't be any canon characters making more than cameo appearances and mentions.
The idea will to be try and stay true to the 'spirit' and feel of the shows and universe, balancing high-action and exciting action with [i]some[/i] elements of relative realism (again, anime giant robot show) against the character drama and relationships, and not getting too mired down in the details and specifics in favour of fun, excitement, and moving the plot forward, as well as the characters getting to do cool things and be Big Damn Heroes. 

Aiming to make this a casual RP, potentially even advanced. I'm fairly relaxed about posting rates and such as well, so looking for one post a week from each player would be fine. 
You won't have to know masses and masses about Gundam or the Universal Century, but at least having seen, read, or otherwise knowing something about it would be ideal. As it is, there's loads of resources and info online I'll be using rather than writing out reams and reams of lore - why not take advantage of what's there already, after all. 

Looking for a minimum of three players + myself to get started, and probably a maximum of no more than six in total. 
Also, players will be restricted to playing Mobile Suit pilots, and for the Federation only; no enemy characters and no support personnel, as it's really hard as a GM to balance everything and keep giving people to do, in my personal experience.