A lot of people like Matt Damon. I know this because, in September 2015, I posted an answer to the question “How much money has been spent attempting to bring Matt Damon back from distant places?” on Quora (posted by Ferdison Cayetano). I answered it as a joke because I thought it was a funny question, and the answer was quite popular on Quora for a few days. Then, around three months later, my answer was picked up by several media websites and it went viral. I have been asked many questions about this piece, a few of which I will try to answer below.
How did you come up with the [fictional] numbers?
All of the Matt Damon rescue missions relate to military and/or space activites. Most of the military cost estimates are based on published costs of private jet charter flights. But these don’t really matter for the overall cost - what makes up the vast bulk of the USD $900B estimate are three space films:
Titan A.E. ($200B): This film is set around the year 3028, where the main cost drivers for saving Matt Damon are (1) Earth evacuation spaceship and (2) Terraforming device to create a new Earth-like planet. In the film, humans are a spacefaring species, so the evacuation spacehip probably cost roughly what a Transatlantic economy class fare costs right now. On the other hand, terraforming is probably still more expensive than gardening. But how much? According to this article, terraforming Mars will cost roughly USD $2 trillion and take hundreds of years. Terraforming a planet from scratch, and much faster, is probably going to cost a lot more energy and money - let’s say $20 trillion. But how much will this energy cost in 1000 years from now? From an online reference I guessed that our current per-capita energy consumption is on the order of 10 times what it was 1000 years ago, at around 10% of the cost. So assuming that we can continue to improve our energy production technology for the next 1000 years, the cost of our terraforming in the year 2038 falls to $20 trillion x 0.1 x 0.1 = $200B.
Interstellar ($500B): This film is set in the near-enough future, and there is a helpful description of the Endurance spacecraft. Our reference point is the $150B International Space Station. The Endurance has 12 modules while the ISS has about 15, so they are of roughly similar internal volume. Also, the launch craft seems to be similar to the NASA Space Launch System, so the cost of getting stuff into space is probably similar to what it is now. However, the Endurance has three major cost-inflating characteristics:
- It is not in low Earth orbit like the ISS, and thus must have required much more fuel and money to get up there;
- It has (heavy) lander and ranger craft which allow for planetary exploration;
- It has more supplies for the much larger distances involved.
Taking all of this into account, I estimated a mission cost of $500B - a bit more than three times the cost of the ISS. And Matt Damon dies anyway (sorry about the spoiler).
The Martian ($200B): Like Interstellar, this film is also set in the near future. The Ares 3 spaceship seems to be roughly similar in size to the ISS, except with a number of extra cool features such as the rotating section to produce artificial gravity. Like the Endurance, it needs to be much further out of Earth’s gravity well than the ISS, and it needs to carry a lot more supplies including a Mars base. However, in this rather more optimistic future vision I decided to assume that companies such as SpaceX can routinely get lots of stuff into deep space much more cheaply; hence the moderate price hike compared to the ISS.
But wait: the whole Mars mission was not really a Matt Damon rescue, just the extra part after they worked out that he wasn’t dead and extended the mission to go back and get him. So the real cost was the extra mission time (let’s say on the order of $100M), plus two resupply launches (around $500M), for a total rescue cost of around $600M. But that makes for a boring headline, so we’ll ignore it…
What are your qualifications for answering this question?
I’ve seen in some of the media headlines that I have been mentioned as a “researcher in Zurich”. This is technically true - I am part-time on the faculty of the Institute of Neuroinformatics of the University of Zurich and the ETH Zurich. Unfortunately, however, I was not paid or given time to answer this question, and it’s definitely not endorsed by any of my employers (they probably don’t even know as of this writing). And no I haven’t worked at NASA, ESA or any military organization. One of the startups I’m involved with has done work for the United States Defense Advanced Research Projects Agency on neuromorphic sensors and autonomous drones, but that’s as close as it gets.
If I do have any relevant qualifications, they are as follows: I have degrees in mechanical engineering and computer science, and once designed parts for gas turbines. So I have guessed engineering things for a living. More recently I have been involved in a number of technology startups, so I also guess the cost of things that don’t exist yet. I’m not rich, so obviously I need more practice at guessing.
Is saving Matt Damon worth the cost?
I can’t answer this question. However, given that the world produces $80 trillion of stuff each year and spends $1.6 trillion on military stuff each year, it seems that in a true emergency situation we’d easily come up with the spare change to save all of humanity (including Matt Damon).
- If you are interested in hypothetical science questions, the best-known is probably xkcd what if? by Randall Munroe. One space-relevant xkcd post is Up Goer Five.
- If you are interested in science in cinema, check out Science Goes to the Movies hosted by Faith Salie and Heather Berlin. They review Interstellar and also talk about space with Neil DeGrasse Tyson.
- Update 2016–01–07: Now Matt Damon himself has been asked about the post on the Today show. This means that the circle has been closed, leading to a social media singularity. Or something like that.
- Update 2016–01–10: If you want to find out how the Quora post went viral, with some graphs and basic analysis with links to neuroscience, you can read about it in this LinkedIn article.