Because NASA isn't getting enough money!

rt.com/usa/163736-mars-nasa-funding-strategy

You need bigger rockets to do bigger things, and NASA doesn't have the budget for that.

Elon Musk's vision

http://en.wikipedia.org/wiki/Mars_Colonial_Transporter

Based on an older vision

http://www.wired.com/2013/01/ford-ae...c-empire-1962/

The issues are the same.

Bigger hotter rockets.

http://www.bobkrone.com/sites/defaul...iam%20Mook.pdf


What we can do today, that we couldn't do in '62:

(1) We know water is abundant on Mars, and a lot about Mars' CO2 atmosphere - so we can make methane and LOX to fuel engines using solar power;

(2) Self-replicating micro-machinery, micro-reactors, convert CO2 to plastics, self-assemble products, again using solar power;

(3) Suspended animation is a solved problem - check out Mark Roth MD;

(4) Anti-radiation medication - check out Ex-Rad;

The Musk Mars Colonial Transporter uses nine methane fuelled Raptor engines in each rocket module. They generate 454 tonnes of force each. That's 4,090 tonnes of force at lift off to propel a 3200 tonne rocket module into space.

A 7 element MCT system, very similar to the one I've described previously, masses 23,650 tonnes at lift off and carries 1,250 tonnes into Low Earth Orbit.

http://www.scribd.com/doc/45631474/S...rived-Launcher

The Mars Colonial transport payload consists of a stage carrying 929 tonne of Methane and LOX. Another 121 tonnes is propellant tank and engines. Finally, 200 tonnes are crew and cargo spread across 253 persons.

The 929,000 kg propellant consists of a 10 meter diameter 17.324 meter long lozenge - with spherical end caps - and a spherical bulkhead 10.58 meters from the bottom end.

The bottom hemisphere is surrounded with an annular aerospike nozzle truncated with a heat shield that is used for boost and for atmospheric entry.

http://www.alternatewars.com/BBOW/Sp...DP_Drawing.gif

The MCT stage is designed very much like the 'wet station' concept by vonBraun from 1964.

Once the tank is depleted, people move in to use the tank interior as a habitat during transit.

A 10 meter diameter x 11.62 meter long pressure vessel with 6 levels, is the former lox tank. It's divided into 252 private cabins which can be joined together in pairs.

At launch 252 people are situated in four rings around the top of the tank's hemisphere, 63 outward facing seats per ring. These seats allow direct access to the outside and operate as individual airlocks, changing stations, where each sit in their own personal long duration space suit.

Each station is self contained and is equipped for ejection and re-entry during launch and landing.

The seats also support suspended animation and emergency medical treatment - so they are a private support centre for each passenger.

There is a 1 meter diameter lock at the centre of the top hemisphere for tank interior access. There is an annular storage space behind the circular wall of 252 outward facing seats. This is the social centre of the ship during transit, allowing one to retire to their personal space.

After landing on Mars, the self replicating machinery builds stuff from the Martian soil powered by sunlight.

https://vimeo.com/25401444

Building a self-sufficient home/factory/farm for each family/person, which is itself capable of self-replication.

The MCT upper stage acts as a hotel during build out of the self replicating system. A 1 tonne replicator takes 11 replications to build 10 tonne habitats for each of the 200 colonists. Of the 253 another 30 are tourists, who return to Earth and 23 are crew, which return or cycle out with crew members on Mars support side.

Once the colonists, tourists and crew members are removed from the ship, the tank is reset for refill, and refilled using solar power to process water and CO2 into CH4 and LOX. The ship then returns to Earth with crew and tourists.

At $500,000 per colonist, the 200 per trip generate $100 million per trip. The tourists pay $3.5 million and generate another $105 million per trip.

The delta vee required to leave Mars on a flight back to Earth is 6.72 km/sec. This requires a propellant fraction of 84.9% With a 929 tonne propellant load, and a 121 tonne inert mass, this leaves 44.2 tonne of return payload. 3 tonnes of Mars materials, mostly for the jewelry trade, are returned to Earth at a cost of $32 per gram. This earns another $100 million per trip.