I think it's still brave to attempt a mission with significant chance of failure that risks resources, careers, and reputation. And had it been a _manned_ mission to Venus, the adjective that comes to mind is not brave but pointless, foolish, or sadistic.

Taking a risk on a project that takes many years with a good chance of total failure can be brave.

Many people are risk averse and would find the total failure of many years of work at the very least very disappointing.

Economically brave. Imagine building the most advanced and expensive piece of technology your society ever created, with small margins of success and the knowledge it'll last less than an hour before imploding upon itself.

And then trying again 16 times.

(I've just learned there are plans to try one more time: https://en.wikipedia.org/wiki/Venera-17)

Apple applied "courage" to removing the headphone jack.