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I have to imagine that if this could be done more efficiently, that plan would be in this proposal.

nkoren 11y ago
Yeah, you'd like to imagine that, but unfortunately it isn't the case. Here's a perfectly credible and very well-studied architecture for a Mars mission with 1/3rd the upmass and ~540 days on the surface. If your objective is time on the surface to inhabit and study Mars, then this would give a 64x better return on your investment: https://en.wikipedia.org/wiki/Mars_Direct https://en.wikipedia.org/wiki/Mars_Direct So why propose something much more expensive with much less return? Because scientists have learned that the NASA projects which get funded and stay funded aren't the projects which are most cost-efficient; they're the projects which spread the money around to as many NASA centers (and, more importantly, states which correspond to the senior members of the Senate Appropriations committee) as possible. That's pretty obviously the guiding light for this architecture; its innovation is that it proposes to do so within existing budgets rather than radically expanded budgets. But that doesn't make it minimal or cheap by any measure.
- simonh 11y ago
  Because nobody is building any of the components for Mars Direct. However many of the components for these missions either exist already or are currently in active development. To do Mars Direct now you'd have to factor in the cost of scrapping everything that's currently in the works and developing Mars Direct from scratch. I appreciate your POV, Mars Direct is a compelling plan, but it's weakness is that none of its components except the launcher are any use for anything else except another Mars Direct mission. Anyway it's a bit unfair to thrash these guys for wanting to work within what is already actually happening.
  - nkoren 11y ago
    In other words, they're stuck in the Sunk Costs fallacy: https://en.wikipedia.org/wiki/Sunk_costs https://en.wikipedia.org/wiki/Sunk_costs
    - simonh 11y ago
      I don't think you properly understand what the falacy is. The falacy is to factor in a sunk cost that has no future value in future decisions. For this proposal to be subject to that falacy, you'd have to show that the products of the current development programs have no future value.
      - nkoren 11y ago
        I'm afraid I have to turn around and say that it is you who does not have a proper understanding of the sunk costs fallacy. The future value of the sunk costs is not important -- in fact, thinking that it is important is the very definition of the fallacy. Rather, the future value of all costs is what is important, whether those costs are sunk or not. To illustrate, here's a simplified example. We can buy one of two Mars missions: Mars Mission A, which costs $100, of which we have already paid a $10 non-refundable deposit, and Mars Mission B, which costs $30, but we have not yet spent anything on it. The $10 we have already spent absolutely does have future value -- $10 worth of future value, if we pursue Mars Mission A. Its future value is, however, irrelevant, because Mars Mission A has $90 worth of future costs, compared to $30 of future costs for Mars Mission B. The Sunk Costs Fallacy is to believe that the $10 continues to have any relevance in such a scenario. In truth, the future costs are the only costs which matter.

Yeah, you'd like to imagine that, but unfortunately it isn't the case. Here's a perfectly credible and very well-studied architecture for a Mars mission with 1/3rd the upmass and ~540 days on the surface. If your objective is time on the surface to inhabit and study Mars, then this would give a 64x better return on your investment: https://en.wikipedia.org/wiki/Mars_Direct https://en.wikipedia.org/wiki/Mars_Direct So why propose something much more expensive with much less return? Because scientists have learned that the NASA projects which get funded and stay funded aren't the projects which are most cost-efficient; they're the projects which spread the money around to as many NASA centers (and, more importantly, states which correspond to the senior members of the Senate Appropriations committee) as possible. That's pretty obviously the guiding light for this architecture; its innovation is that it proposes to do so within existing budgets rather than radically expanded budgets. But that doesn't make it minimal or cheap by any measure.

simonh 11y ago
Because nobody is building any of the components for Mars Direct. However many of the components for these missions either exist already or are currently in active development. To do Mars Direct now you'd have to factor in the cost of scrapping everything that's currently in the works and developing Mars Direct from scratch. I appreciate your POV, Mars Direct is a compelling plan, but it's weakness is that none of its components except the launcher are any use for anything else except another Mars Direct mission. Anyway it's a bit unfair to thrash these guys for wanting to work within what is already actually happening.
- nkoren 11y ago
  In other words, they're stuck in the Sunk Costs fallacy: https://en.wikipedia.org/wiki/Sunk_costs https://en.wikipedia.org/wiki/Sunk_costs
  - simonh 11y ago
    I don't think you properly understand what the falacy is. The falacy is to factor in a sunk cost that has no future value in future decisions. For this proposal to be subject to that falacy, you'd have to show that the products of the current development programs have no future value.
    - nkoren 11y ago
      I'm afraid I have to turn around and say that it is you who does not have a proper understanding of the sunk costs fallacy. The future value of the sunk costs is not important -- in fact, thinking that it is important is the very definition of the fallacy. Rather, the future value of all costs is what is important, whether those costs are sunk or not. To illustrate, here's a simplified example. We can buy one of two Mars missions: Mars Mission A, which costs $100, of which we have already paid a $10 non-refundable deposit, and Mars Mission B, which costs $30, but we have not yet spent anything on it. The $10 we have already spent absolutely does have future value -- $10 worth of future value, if we pursue Mars Mission A. Its future value is, however, irrelevant, because Mars Mission A has $90 worth of future costs, compared to $30 of future costs for Mars Mission B. The Sunk Costs Fallacy is to believe that the $10 continues to have any relevance in such a scenario. In truth, the future costs are the only costs which matter.