My assumptions around building up infrastructure for dealing with space launches from Venus assumes colonization based on the principles outlined by Geoffrey A. Landis of NASA in paper Colonization of Venus.
To summarize. This assumes we DON'T build bases on the Venus surface which is too hot and with too high pressure but rather 50 km above surface where temperatures are 0-50 Celsius and pressure is the same as on earth. The thick atmosphere gives a lot of buoyancy even for balloons with regular air. So it is feasible to build large habitats hanging in the air or existing inside balloons with breathable air.
I think these ideas are quite interesting, however staying in the atmosphere deprives a colony of many resources, so I am interested in finding out about the economics of utilizing asteroids from Venus. Accessing the asteroids could happen in many ways. Either by going from Venus straight to the Asteroid belt, mine them and return the resources. Alternatively pull one or more asteroids from the asteroid belt and deposit them in orbit around Venus for later processing. E.g. one could potentially maintain processing facilities in orbit as well.
This suggests to me that one depends on avoiding to have to build spaceships on Venus or doing complicated repairs.
So I imagined one could enter Venus and "land" similar to how it is shown in this article on HAVOC.
- Inflate balloons rapidly on entry to keep space ship floating in Venus atmosphere instead of hitting the surface.
- Move with Zeppelin like vehicle to "landed" space ship with e.g. materials from asteroid and refuel spaceship. If it is multi stage, collect the pieces and assemble it first.
- Start rockets and fly up again. I assume start angle doesn't matter that much as you can probably adjust later.
On the earth one would need to hit hard soil at very accurate angle and not hard enough to destroy the space ship (launch vehicle), or alternatively land in the sea which based on what I've read about the shuttle program causes lots of maintenance problems. On Venus of course you avoid this as you don't need to hit at any specific angle or altitude on re-entry.