Some facts.
(1) Russia [Soviet Union] has been doing unmanned rendezvous/docking
missions since 1967.
(2) Any manned mission to Mars will require hardware of at least 140 short tons [minimum] starting off from Earth orbit...And that's with VASIMR propulsion for a minimum manned Mars mission [two humans on the Martian surface for a couple of weeks]....More realistically, you're probably looking at close to 250-300 tons.
(3) That means? You have to assemble that hardware in Earth orbit very quickly, before orbital decay sets in, and before all that volatile fuel
starts to boil away.
(4) You'll need automated docking systems.
(5) That's why the DART mission tonight is so important for you Marsbats.
It fails, you have to wait longer for your Mars manned mission in the future.
Any future manned mission to Mars depends on the success of tonight's DART mission.