Elon Musk wrote a 16-page article that described a plan to reduce the cost to bring one person to Mars down to $100,000.
Elon Musk has a ballpark assumption that allocating one-ton of mass is enough for the passenger, supplies, and luggage.
Improving the Cost Per Ton to Mars from $10 Billion $200,000
Elon sees the following key elements to lower the costs to Mars.
Most of the improvement would come from full reusability somewhere between 100 to 500 times cheaper. SpaceX already has made 70% of the Falcon 9 block 5 reusable. SpaceX is on the way to making a fully reusable Super Heavy Starship.
Refilling the fuel for rockets in orbit will lower the costs by about 5 times.
Making the fuel on Mars will enable the rockets to be sent back. Making fuel on Mars will allow the rocket to be 5 to 10 times smaller.
Methane is clearly the best fuel to use for lower cost rockets. Methane would require from 50% to 60% of the energy on Mars to refill propellant using a propellant depot. The technical challenges are far less for making methane fuel on Mars than any other option.
Very dependent on volume, but I’m confident moving to Mars (return ticket is free) will one day cost less than $500k & maybe even below $100k. Low enough that most people in advanced economies could sell their home on Earth & move to Mars if they want.
— Elon Musk (@elonmusk) February 11, 2019
Elon figures there needs to be at least one million people in a Mars city is order to make it self-sustaining. Later version of the Mars transports will be bigger. Elon wants to scale up to 1,000 ships carrying 100 to 200 people each.
Elon paper did not discuss sending more supplies and material separate from the passenger missions. Using cyclers that orbit between Earth and Mars to transport cargo, the costs could be reduced.
Elon things it could 20 to 50 fleets sent every two years to create the million person city. This would take 40–100 years to achieve a fully self-sustaining civilization on Mars.
Elon’s 16-page paper was from 2016 which was based upon the 550-ton payload Interplanetary transport. Currently, SpaceX is building a 100-ton payload Super Heavy Starship.
Hibernation Could Reduce the Mass Needed for Each Mars Passenger to 30-50%
A NASA study looked at crew hibernation into a state of Torpor to reduce the weight needed to sustain people to Mars. NASA had a reference of using about 10-tons per person for slower 500 day trips to Mars. SpaceX wants to send people to Mars in about 90-days each way. The hibernation system could reduce the weight of the slow Mars trips per person down to about 4.5 tons per person.
Purdue Project Destiny Explored SpaceX ITS Variants for Mars City
In 2017, Purdue University engineers created a 331-page analysis for the Mars City. They looked at Mars food production, mining and the use of large cyclers.
They had a high cost of about $4 billion for each SAFE-800 nuclear reactor for cycler power.
The cost of nuclear reactors for space could be greatly reduced with the Kilopower reactors and the Los Alamos Megapower reactor which could be built as the Westinghouse eVinci reactors.
The eVinci could have over twelve times the power level as the SAFE-800. The eVinci could produce 10 megawatts instead of the 800 kilowatts of the SAFE-800.
SOURCES- New Space, Purdue University, Elon Musk, SpaceX
Written By Brian Wang. Nextbigfuture.com