Your ticket to Mars

 In July this year (2021) [Update, 27/3/22: It still hasn't happened yet.  Current timetable is before the end of this year, 2022], SpaceX will test its monster combination of Super Heavy (the booster) and Starship (the spaceship/second stage) for the first time.  As is his wont, Musk decided to create the hardest part first: Starship.  SpaceX knew a lot about re-landing and re-using boosters, with its Falcon 9, so they left the construction of the booster until they had a working prototype of the upper stage.  The wrinkles have by no means all been ironed out--the heat-resistant tiles needed for re-entry are still untested, for example--but three key techniques have been tested, and found to work.  First, it is clearly possible to construct a rocket out of stainless steel; second, the completely new methane-burning Raptor engine works; and last, the famous skydiver fall, which is designed to bleed off velocity on re-entry, works too.  These are formidable achievements, especially given how rapidly development has proceeded.

So it's time to relook at the cost of a ticket to Mars.  Musk has said that each launch of the Super Heavy/Starship combo will cost under $2 million, and will lift 100 tonnes to LEO (Low Earth Orbit).  That alone will be remarkable if achieved.  The cost of lifting 1 kilo to orbit will have fallen from $22,000 before SpaceX was founded, to $20 with Starship, a three orders of magnitude decline.  Ignoring all the on-costs (food, life support, cabin crew) a flight to LEO would cost the average overweight Westerner with 20 kilos of luggage about $2400, about  the cost of a return air ticket from the UK to Australia.  

To get to Mars, though, the Starship will have to refuel in orbit (another significant technical hurdle).  Since the journey to Mars will need 1000 tonnes of fuel and oxygen, each Starship heading to Mars will need 10 flights from the Earth to LEO to fill up.  So the cost of a flight to Mars will be equivalent to 11 Starship launches, or $22 million.  Assuming each passenger plus his or her food, belongings, and cargo weighs 1 tonne, that will mean that a ticket to Mars will cost $220,000.  Per person.  By comparison, when NASA costed a potential Mars expedition to Congress, it estimated 15 BILLION for 5 astronauts.  $3 billion EACH.  

Of course, there will be other costs and SpaceX has to make a profit and cover its development costs, but you get the picture.  Also, for the first few expeditions to Mars, most of the Starships sent there will remain, as makeshift habitats while more permanent dwellings are built.  But Musk has said that each Starship's capital cost is roughly $5 million.  Plus, for the first few expeditions, for every crewed Starship there will need to be perhaps 10 cargo Starships, carrying rovers, solar panels, wind turbines, inflatable habitats, air purifiers, food, medicines, and other equipment.  The total cost of the expedition will therefore be, roughly, $250 million.  For subsequent expeditions, more and more of the Starships used will be able to return to Earth, and more and more stuff will be made on Mars, cutting the costs progressively.   And in time the cost of a one-way ticket will fall below $220,000 as we move down the learning curve. 

Will people be willing to pay that much for a dangerous, uncomfortable trip to a far-away world from which they might never return?  Obviously, billions will be far too poor to do so.  But there could easily be a few thousand a year who will be willing and able to pay.  And for the more expensive first few expeditions, I guess that many cabins will be paid for by NASA, ESA, JAXA, or indeed any government space agency who wants to do science on Mars.  

SpaceX's "aspirational"  timetable has prob'ly irretrievably slipped.  They had planned the first uncrewed  journey to Mars at the next "orbital sync" at the end of 2022.  That probably won't happen until the "orbital sync" after that, at the end of 2024/early 2025, though SpaceX may well send a couple of uncrewed Starships in 2022 just to see if they can safely land, allowing them to send a crewed expedition in late 2024.  

10 years ago, a journey to Mars still seemed fantastical.  Now it looks more and more likely that it will happen, and that by the end of this decade, we will have settlements on the red planet.