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Essentially all Mars missions under serious consideration rely on special alignments of planetary orbits to minimize the fuel required. That leads to very speci

by Steuard 14y ago

Essentially all Mars missions under serious consideration rely on special alignments of planetary orbits to minimize the fuel required. That leads to very specific "launch windows" that may only occur every few years. For an Earth-Mars trip, the basic launch window is available roughly every two years, but there are particularly low-energy opportunities every 16 years or so. My understanding is that the next of those will be the 2018/2020 launch windows, which is almost certainly too soon for a mission to be ready. So the following low-energy opportunities will be somewhere in the mid 2030's. That's not to say that it would be impossible to use a launch window in the mid-2020's despite the higher fuel cost (or even some other orbit entirely that didn't try to minimize fuel at all), but doing so would be substantially more difficult. Here's a link that is useful primarily because it links to more thorough discussions: http://en.wikipedia.org/wiki/Exploration_of_Mars#Launch_windows http://en.wikipedia.org/wiki/Exploration_of_Mars#Launch_wind...

maaku 14y ago
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.
- crusso 14y ago
  Exactly. The 2030s are just beyond what we could demonstrably prove ISN'T currently in the works.

by Steuard 14y ago

maaku 14y ago

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.

crusso 14y ago
Exactly. The 2030s are just beyond what we could demonstrably prove ISN'T currently in the works.