A few years ago, I attended a science fiction convention where one presentation discussed the number of launches it would take to achieve Elon Musk’s goal of moving one-million people to Mars over an assumed 10-year period. At 100 passengers per launch, that would be 100 launches per year (10,000 people)—two a week. SpaceX Mars colonization program – Wikipedia.
I’d travel to Starbase in Texas to watch that.
I should note here, the presenter estimated about 10 times that number of launches to send materials, components for the habitat, fuel for getting the Starship upper stage to and from Mars, landing on Mars, and so on. That required 1,000 launches per year or 20 per week. Putting is gently—he was a skeptic.
But I would look at this from a different perspective and consider how much weight Starship can launch into orbit. To keep it simple, I’ll use the information from Wikipedia and use the figure of 150 metric tons per launch. SpaceX Starship – Wikipedia (Note: the space shuttle could deliver 25 metric tons to orbit. Space Shuttle – Wikipedia)
Let’s suppose we want to send one-hundred people, including their “luggage” allotment, at 500 pounds per person. That’s about 226 kilograms per person, or 22.6 metric tons of people and their stuff, per launch. So what do you fill Starship with? What makes up the other 125 metric tons for that launch?
Good question. You’ll need supplies, of course, for the three-month trip. But you could throw in, say, 100 metric tons of supplies.
Why is that important? Well, one estimate we can use is they’ll need 1 million tons of supplies and materials to build a city for the 1 million people. That would be about 6,700 launches. But maybe some of that could go with the passenger launches, perhaps as much as 100,000 tons. Consider that a contingency perhaps.
Regardless, 10,000 launches might not be a bad estimate of what it would take.
Which brings me to the other two drivers of how we can get the materials needed to build a city on Mars and move 1 million people: how many ships are available and how much time does it take. Let’s start with estimating 40 years to complete the project. If we do indeed need 10,000 launches, that’s 250 launches a year, 5 per week. That still seems like a lot, but there’s been talk about a sub-orbital, rocket system for passenger service around the world. (see my blog Breakfast in New York – Lunch in Singapore – Dinner in London); 5 launches a week might just be doable.
Finally, how many ships would we need? If the refurbishment/turnaround time is one month, for example, some number of ships are in transit, and maybe some stay in orbit or on Mars, would 100 be unreasonable? Numbers are feeling more manageable.
To put it in human-size terms, we’d need 100 ships, launching 5 times per week for 40 years. That’s manageable in less than a single lifetime. If I had a trillion dollars, I might do that; perhaps somebody will.
Or we could do one and done. (Of course, I have to bring sci-fi into this.) In the classic 1951 film, When Worlds Collide, humanity is saved in a single ship, with a single launch, with everything they need for the new world, including livestock.
Doable? Likely not, but a fun movie.
Check it out: https://youtu.be/avtQ8elxL-o?t=96
(My apologies for any YouTube ads).
Buckle up, we are go for launch.
Thanks for stopping by.
Wow bro’…that’s a lot of calculations…seems like a long time to reality though….interesting…