Sunday, January 25, 2015

Red lander

In CJ's last post (his best yet) he mentions 10 passenger mars landers. Does this fit within the parameters of the previous 4 passenger, 2500 kg payload landers? Easily.

Volume is no issue. If you've seen photos of existing Dragons it's obvious there is room for 10 for a short duration landing. Assuming each suited crew is 200 kg that leaves 500 kg of consumables. 50 kg each or about a week of supplies... enough to get them to a prepared surface habitat. They aren't going to stay in the lander any longer than they have to.

At $150m per lander which can bring more than 500 kg to the orbiting ship if needed that gives us a per crew cost from orbit to surface of $15m each. Add another $15m from earth to LEO and we only need an estimate for orbit to orbit (will update in a bit) to get total cost per crew.

$50m total sounds about right. About a third my former estimate.

[Update: 185 ton of fuel and supplies requires 3 FH or one BFR so let's call that $300m or $3m per crew. I'm going to stick with my $50m total per crew estimate.]


C J said...

Ken, when it comes to cost, there are so many variables.

I tried to answer in this comment, but the character limit won't allow it. So, let me save that for later and cut to the chase; the difference between a low cost per pound BFR (R&D and construction costs offset by commercial use) vs. a dedicated system is enormous. Same goes with MCT (which is why I find basing it on modules with other purposes so appealing). Another huge factor is how often the MCT will make the journey.

The impact on per-mission cost? Freaking enormous. At two of three mission per decade with no offsetting, you're looking at 5 billion or more per mission. At the other end of the scale, 70 million per mission (not counting the value of the cargo).

I'll lay out the reason behind both estimates, and all the factors involved, in a soon-coming post.

And BTW, the low end may sound preposterous, but for a model of that, look at transatlantic airfares in the early 60's (first jet airliner service) compared to later in the same decade. They came down by more than an order of magnitude. (they started at over $5000 per person, one way, in today's dollars). The biggest cause of the price drop? The number of flights and aircraft.

ken_anthony said...

I always look for the lowest possible cost with the understanding that there is no upper limit to what a thing can cost.

I look forward to your pending analysis.

C J said...

I'm working on it... basically figuring out ballparks for BFR and MCT (what they'll cost to develop and build) and going from there, to see what would be required, demand-wise, to attain reasonable costs.

For the moment, I think I can safely pin down the price of a ticket to Mars within a few orders of magnitude, and say it'll be between five thousand and 500 billion per seat. :)

ken_anthony said...

Safe? Yep. Useful?