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Old October 3rd 16, 12:59 AM posted to sci.space.policy
William Mook[_2_]
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Default Musk plans for mars

I think with his two stage RLV design 400 tons is more achievable, but if he can get his structure fraction down to 3.5% from 4.2% - he can get another 50 tons out of the deal.

They will likely go to Mars in stasis, in large fleets orbited over the entire synodic period. That way capital utilisation is maximised. Meanwhile, 'live' crews - mostly doctors - visit those in stasis. They're awakened on a schedule every 28 days - and surgeries cosmetic and other can be scheduled as well. People spend a day or two in awakened state - and assessed physically and psychologically. In this way over a 90 day to 120 day trip - people can enjoy a very fine luxury experience - at minimal cost in terms of weight or money.

http://www.sei.aero/eng/papers/uploa...2010162015.pdf

This was presented at the 66th IAF conference - and Musk was there. Just saying.

200 t - 300 kW - 100 people. So, 400 t 600 kW - 200 people - is his payload.



On Sunday, October 2, 2016 at 11:54:41 AM UTC+13, bob haller wrote:
On Tuesday, September 27, 2016 at 3:41:42 PM UTC-4, JF Mezei wrote:
Musk outlined some plans for mars colonisation. He says the plan is to
bring transport costs down by many orders of magnitudes so that the
ticket prices are closer to the cost of a home (so paople can move to
Mars easily).

Musk plans to build mega rocket (bigger than Saturn 5) with 100
passengers per trip. Musk looking at expanding to 200. Plan is to send 1
million people to Mars.
Rocket should have ~10,000(t) compared to Saturn 5 ~3000 (t)

Stage 1 would have 128MN of thurst at sea level, 42 Raptor engines.

Landing the stage 1 back would cost about 7% of fuel. (down from current
use).

Of the 42 engines, 7 in the centre would be gimballed, the rest would be
fixed.


450 tonnes of cargo to Mars. Trip time caries betwene 80 and 140 days
depending on year/planet alignment.



To achieve this, there are some concepts that need to be implemented:

Full reusability
Since it takes so long for the return trip, Musk says about 12 re-uses
for the interplanetary ship lasting about 20-30 years.

In-orbit refuelling
The interplanetary ship is launched without fuel, orbits earth after
launch. Second launch bring up fuel, docks to the first ship to transfer
fuel and then interplanetary ship departs.

Tanker version of spacecraft will launch 3 to 5 times to transfer enough
fuel for each interplanetary ship and for each launch window, there
would be many interplanetary ship launched and fueled (so the launch pad
would be busy launching them and the refueling ones.

Produce propellant on Mars
Loading propellant on earth for the return trip from mars costs way too
much.

Right choice of propellant
This one is simple: methane. Hydrogen could also be produced on mars but
very hard to store and requires much bigger tanks.


Musk wants to R&D so that carbon fibre can be used for tanks.