A manned craft to Mars in the next 75 years?
Look at how far technology has come since the US landed on the moon (sorry conspiracy nuts, but yes we did go to to moon). If humanity collectively put their resources and minds to the task, it could happen.
Too bad we’re spending all that time and energy thinking of new ways to kill each other.
If Mars was discovered to have oil, diamonds, and hot alien women, we’d be there by the end of the decade.
It’s all about motivation. We have the capacity to pull it off but there’s no incentive.