Although, as noted above, I always go on the Battlefleet gothic ruling that sub-cruiser transports can land, albeit a distinctly slow, vulnerable and noisy process that could only be done once a 'beachhead' is secure.
I apparently need to go back and look at that again, since I don't remember that from the rules. It does cast an interesting light on the Starport on Damaris though. My run through made the assumption that it was essentially just like a large airport for heavy lifters and small craft to unload ships from orbit and supply the Bulwark. But, if it actually has a couple cradles for large transports, it would have made resupplying the capitol much more Imperial friendly.
Can a voidship land on a planet?
I apparently need to go back and look at that again, since I don't remember that from the rules.
Probably this rule which I referenced earlier?
"Escorts and Transports which voluntarily move off the planet edge are said to have landed and are removed from play; capital ships cannot land."
- Battlefleet Gothic rulebook p.48: Fighting in Low Orbit
Thank you lynata I was about to reference the same thing. You are exactly right!