Astronaut Suit

[Enkidoh]

We have no actual need for it though as the Warrior of Light can breathe in space (

you can breathe on the Moon because of it's artifical nature - the lopporits are using the rainbow crystals via Creation Magic to create air on it's surface, and Ultima Thule is given a breathable atmosphere due to the Scions, specifically Thancred, sacrificing themeselves when you first arrive there and their aether interacted with the dynamis of the place to make the area breathable from then on.

Also it appears the Ancients could breathe in space as well - Venat seemed to reach low Etheirys orbit on Argos's back unprotected when she chased Meteion into space without ill effect, and Emet and the rest of the Convocation appeared to summon Zodiark above the planet (that dark crystal like platform area where the final boss of Amaurot was fought), again with no problems breathing,

so we could just handwave that away as this again just being 'fantasy' so reality need not apply.

We sort of already have a kind-of futuristic space suit thing of sorts with the Late Allagan PVP gear that looks like a tight space suit, only lacking an enclosed helmet, so that's kind of a stand in for now. (So maybe a classic pulp-sci-fi bubble 'Space Explorer Helmet' might be enough?)