The Wasp LAM entry in TRO3025 mentions landing fields on Capra (as of 3017).
For what it's worth, Capra is repeatedly mentioned in Wolves on the Border as one of the worlds garrisoned by Wolf's Dragoons. No planetary data given or inferred in the novel though.
Some coverage is found in the War of 3039 sourcebook: Capra is "little more than a rock in space with a few scattered mining colonies", the largest being New Cassandra which is also the seat of the government and the "heart of the industry". Trading towns are mentioned besides the mining settlements. An "airfield outside of Kirit" is mentioned, suggesting Kirit to be a major city or colony some 200 kilometers from New Cassandra.
Militia battalions are mentioned, most of them infantry, which to me suggests a breathable atmosphere.
Starterbook: Sword and Dragon contains a Touchpoint: Capra, where a DCMS supply depot comes under pirate attack in 3048. The world is (again) explicitly called unimportant. A place named Paulo Bay and a place named Fort Jinjiro are mentioned on Capra.
Warchest rules include "+200 Tangled Forests", and a miniatures diorama image on p. 78 captioned as a scene on Capra shows a rocky slide with green bushes and trees. This, and the lack of special rules or other information to the contrary, seems to indicate an open environment and a breathable atmosphere.