[arp242]

Lots of things are east to imagine in principle, but actually doing them is just so much harder. There are so many practicalities you run in to.

The first from the top of my head would be the required length and sheer weight of the cable attached to that Teflon balloon, to say nothing of the weight of the balloon itself or its contents. Speaking of which, actually keeping the contents in that balloon might also be surprisingly tricky.

You need to drag that all the way to Venus, then decelerate enough to stop all that mass, then accelerate that again to come back to Earth, before decelerating to land here. Even without any extra weight that's actually a huge challenge due to the amount of fuel required. There's a reason none of the Mars rovers have come back.

[pavel_lishin]

The balloon wouldn't contain anything except a gas that's more buoyant than the Venusian atmosphere at the desired height, and maybe we can use the atmosphere itself, just heated up - similar to how hot air balloons work, except presumably fully enclosed.

Not to say it'd be easy, but certainly easier than landing & returning.