The difference between the Hohmann transfer orbit available every two-ish years and the low-energy opportunities is not significant enough to impact mission via

The difference between the Hohmann transfer orbit available every two-ish years and the low-energy opportunities is not significant enough to impact mission viability. The reason a mission to Mars is "scheduled" for 2030's is because that's the nearest date outside of government budgeting schedules. It would take us 10 years to put together a focused effort (like the Apollo program), there's absolutely no plan to do so right now or over the next 10 years of the government budget. So by that sketchy line of thinking, the earliest this could happen is 2013 + 20 years, or 2033. Maybe I'm showing my age, but I remember a decade ago "the Mars landing" was scheduled for the 2020's. In the 90's we were talking about the 2010's (now!). I bet you when 2020 rolls around, it'll be the 2040's that we're looking towards.