NASA was ready to send people to Mars in 1986 - for that matter von Braun had a plan to do it in 1952.
Through a means of propulsion that the greenie-weenies in Congress will never agree to today. What's more, the fuel-to-thrust ratio was ridiculously impractical. What's more, the cost of going up was high and the success factor was not promising. And let's face it: NASA gets violently bagged on for double-digit million-dollar failures. What do you think would happen if they engaged in a multi-trillion dollar failure?
for that matter von Braun had a plan to do it in 1952.
And it still took another 17 years just to make it to the moon.