At the recent Starship Congress in Dallas, writer, librarian and futurist Heath Rezabek discussed the Vessel Archives proposal — a strategy for sustaining and conveying Earth’s cultural and biological heritage — which was directly inspired by Gregory Benford’s idea of a Library of Life. Working with author Nick Nielsen, Rezabek is concerned with existential risk — Xrisk — and the need to ensure the survival of our species and its creations in the event of catastrophe. Rezabek and Nielsen’s presentation was the runner up for the Alpha Centauri Prize awarded at the Congress, and it was so compelling that I asked the two authors to offer a version of it on Centauri Dreams. Heath’s work follows below, while we’ll look at Nick’s in tomorrow’s post. Both writers will be returning on a regular basis for updates and further thoughts on their work.

by Heath Rezabek


Some challenges are too daunting to approach alone.

Existential risk is certainly one; bringing a comprehensive strategy to a room full of seasoned interstellar advocates is another. Collaboration can sometimes be a greater challenge than solo work, but often it yields rewards far greater than the sum of their parts. I met Nick Nielsen through his asking an audience question of me, after my first presentation of the Vessel proposal at the 100 Year Starship Symposium in September 2012. My work with Nick has been a continuing process of encountering unexpected ideas in unexpected combinations, and this collaboration led us to propose and present a combined session on our work since 2012: ‘Xrisk 101: Existential Risk for Interstellar Advocates’, at the first Starship Congress, organized by Icarus Interstellar, in August 2013.

I have felt the importance of answering the challenge of existential risk (put simply, risks to our existence) since the moment my own sense of this subject achieved critical mass and began drawing all other related ideas into its orbit — which I can, amazingly, pin to the reading of a key article in io9 on June 18 of 2012. This reading began a process of nearly frenzied integration and streamlining, which culminated in a draft proposal for very long term archives and habitats as a means of mitigating long term risk, presented at 100YSS 2012. My preprint of that first, sprawling, 52 page paper emerged from a month of intense creation. It is still available on figshare.

I call these proposed installations Vessels. While this is a discussion for later, I deliberately invoke that term as the best and most descriptive one available, for something which includes all senses of the word that I can find: not only the sense of a craft, but of a receptacle, a conduit, a medium. If an eventual interstellar vessel does not contain a Vessel, then it may be incomplete.

I had no idea, going into 100YSS 2012, whether this proposal had any merit or use whatsoever. Being a librarian by career and calling, it certainly felt right, as the first and last and best I could do. Yet meeting Nick Nielsen was pivotal: his patient unpacking of the implications of mitigating Xrisk for the future of civilization has been crucial to my own optimism over humanity’s prospects, should we fulfill our full potential.

Offered here is a post which casts our Starship Congress 2013 session into blog format. The content can be found in much the same form in our video and slides, but I still encourage you to view them both if you connect with any of these ideas whatsoever. For links to video and slides, go to

Though the concept stands for risks to our very existence, existential risk or Xrisk is far from intractable or imponderable. Because of the subtypes described in our session below (Permanent Stagnation and Flawed Realization), we can do much to improve the prospects for Earth-originating intelligent life tomorrow by working to improve its prospects today.

This begins with directly mitigating the extinction risks that we can, and with safeguarding — to the best of our abilities — our scientific, cultural, and biological record so that future recoveries are possible if needed; and the Vessel proposal attempts a unified approach to this work.

“Build as if your ancestors crossed over your bridges.
— Proverbial


Xrisk 101: Existential Risk for Interstellar Advocates (Part 1)

(Xrisk 101) is divided into two parts. In the first, I will cover the fundamentals of Xrisk, and update on the Vessel project, a framework for preserving the cultural, scientific, and biological record. In the second, Nick Nielsen will explore the longer term implications of overcoming Xrisk for the future of civilization.

Though discussed in other terms, Xrisk was a key concern and priority for the DARPA 2011 starship workshop. In its January 2011 report, that workshop prioritized “creating a legacy for the human species, backing up the Earth’s biosphere, and enabling long-term survival in the face of catastrophic disasters on Earth.” [1]

At the 100YSS 2012 Symposium, I presented a synthesis of strategies to address all three of these goals at once, called Vessel. Before updating on the Vessel project, I want to talk first about Existential Risk, what it includes, and why we should prioritize finding ways to meet its challenge.

Existential Risk denotes, simply enough, risks to our existence. Existential Risk encompasses both Extinction Risk and Global Catastrophic Risk.

Nick Bostrom, Director for the Future of Humanity Institute, defines Existential Risk this way in a key paper we’ll cover throughout, Existential Risk Prevention as Global Priority : “An existential risk is one that threatens the premature extinction of Earth-originating intelligent life, or the permanent and drastic destruction of its potential for desirable future development.” [2] In an array of possible risks presented in the paper, small personal risks are down in the lower left, while situations of widespread suffering such as global tyranny are in the middle as Global Catastrophic Risks. Finally, the destruction of life’s long term potential defines Existential Risk, in the upper right.


Xrisk has become a popular shorthand for this whole spectrum of risks. We can see signs of it emerging as a priority for various space-related efforts. One of the most popular images of Xrisk today is that of a sterilizing asteroid strike. And asteroids play a big role in some of the most visible efforts in space industry today, such as the ARKYD telescope or NASA’s asteroid initiative. Specialists sometimes see unpredicted cultural or technological Xrisks as even more urgent.

Starship Congress had its eye on some pretty long-term goals, and Earth provides our only space and time to work towards them. On that basis alone, the challenge of Xrisk must be answered.

But setting aside our own goals, what are the stakes? How many lives have there been, or could yet be if extinction is avoided? Nick Bostrom has run some interesting numbers.

“To calculate the loss associated with an existential catastrophe, we must consider how much value would come to exist in its absence. It turns out that the ultimate potential for Earth-originating intelligent life is literally astronomical.” [2]

How so? First we need a standard for measurement. Let’s start with the total number of humans ever to have lived on Earth. Wolfram Alpha lists the total world population as 107.6 billion people over time. The current global population is 7.13 billion. If we leave out the current population, we get 100 billion — About the number of neurons in a single human brain.


100 billion lives.

One Pale Blue Dot.

Here’s an excerpt of Carl Sagan’s thoughts on that famous image of Earth from afar:

Consider again that dot.

That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

In … all this vastness … there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand.


100 billion lives is our basic unit of measure.

Now; How much value would come to exist if our future potential is never cut short?

1016 — 10 million billion — is one estimate of the potential number of future lives on Earth alone, if only 1 billion lived on it sustainably for the 1 billion years it’s projected to remain habitable.


But if we consider the possibility of the spread of life beyond Earth, or synthetic minds and lives yet to come, Bostrom’s estimate [2] grows vast:

1052 potential lives to come. 100 million x 100 billion x 100 billion x 100 billion x 100 billion


This means that reducing the chances of Xrisk by a mere 1 billionth of 1 billionth of 1 percent…

is worth 100 billion billion lives.



With just a slight shift in priorities, we can hugely boost the chances of life achieving its full future potential by working to enhance its prospects today.

Let’s look at Bostrom’s definition again: “An existential risk is one that threatens the premature extinction of Earth-originating intelligent life, or the permanent and drastic destruction of its potential for desirable future development.”

Notice that fragment – “… destruction of its potential for desirable future development.” Survival alone is not enough. In some cases, a surviving society may be brutalized, stagnant, or diminished irreparably, unable to aspire or to build itself anew. This brings us to two subtypes of Xrisk as crucial as extinction itself, and both fall into the realm of Global Catastrophic Risks.

  • Permanent Stagnation – Humanity survives but never reaches technological maturity or interstellar civilization.
  • Flawed Realization – Humanity reaches technological maturity but in a way that is irredeemably flawed.

Pop culture has a working knowledge of them both, in different terms. Nick and I joke that it’s a bit like: Zombies vs Vampires.


Permanent Stagnation and Flawed Realization. Losing our capability as a civilization, or enduring only in a deeply flawed form. These two risks fill our dystopian movies. But because popular culture understands them, we can learn valuable lessons about our messaging and priorities by understanding them too.

These two types of Xrisk cut to the heart of what it means to achieve our full potential. There is a vast opportunity between these risks, because of the many advances needed to achieve an interstellar future – and because of the benefits such advances could have for life on Earth — in areas such as habitat design, energy infrastructure, biotechnology, as well as advanced computing, networking, and archival.

If we work to prototype here and now, solving real-world problems along the way, all will benefit. If we make advances open and adaptable to humanity’s best minds, we will gain allies in our effort to uplift Earth and thrive beyond it. Perhaps advanced, resilient technologies could carry a seal standing for the dual design goals of uplifting life on Earth while advancing our reach towards the stars. Like LEED certification for an infinite future. What would such projects be like?

Last year, I proposed the Vessel project as a means to safeguard cultural potential on Earth and beyond. I’ll close with a brief update on this approach to advanced computing, compact habitat design, and long-term archival. With deep appreciation to Paul, I’ll continue in future guest entries by updating on the progress of the Vessel project, as I’ve continued to connect with interested specialists in several areas crucial to its implementation as a concrete strategy for Xrisk mitigation.


Image: Vessel Installation Symbol.

Vessel, as a design solution, begins with a simple premise: Capability lost before advanced goals are reached will be very difficult to recover, without a means of setting a baseline for civilization’s capabilities.

A Vessel is an installation, facility, or habitat that serves as a reservoir for Earth’s biological, scientific, and cultural record. Into a Vessel is poured what must be remembered for humanity’s potential to be maintained. On Earth or beyond, a Vessel habitat is designed to carry forth the sum of all we’ve been. In 2012, Vessel was pictured as the Lilypad seasteading habitat.


But different Vessels would have different designs based on their needs and settings. These traits remain key in each case:

At a Vessel’s core would lie biological archives, meant to preserve key traces of Earth’s biodiversity. Here the primary model is Gregory Benford’s groundbreaking 1992 Library of Life proposal. Benford details a program for freezing and preservation of endangered biomass for possible future recovery. [4]

Also crucial would be core archives for cultural and scientific knowledge, both physical and digital. I’m working with Icarus Interstellar to make sure the Vessel framework is compatible with Icarus projects. Several examples exist of information storage technologies engineered to endure the passage of time, such as the digital DNA encoding strategies of George Church’s team as well as Ewan Birney and Nick Goldman’s approach, the fused quartz technologies of Hitachi or Jingyu Zhang, and the Rosetta Disk project of the Long Now Foundation, which is the first deliverable for their Library of the Long Now. As yet I have not seen it proposed that such initiatives could or should be brought together in the service of a unified goal or project. Throughout 2014, I will be surveying these proposed strategies, as well as interviewing (when possible) their inventors and project leads on potential implementations.


Surrounding these archives would be Research Labs, where specialists could collaborate on advanced technologies, seeking critical paths which avoid and mitigate Xrisk. Or, in a time of recovery, sealed labs could be the birthplace of new beginnings. Research Labs would open inwards to draw upon the Core Cache. Experts in their relevant fields could be both stewards and users of the core archives.

But in the near term, through an outer ring of Learning Labs, Vessel facilities could welcome the curious, and give visitors an inspiring glimpse at advanced studies. Immersive labs could be catalysts for change, helping people understand the arc of history in nature, culture and science, the common risks ahead, and the limitless possibilities if Earth achieves its full potential. This function, familiar in one form to any who have visited a nature & science museum and seen paleontologists at work, hints at a pathway towards actual present-day implementations of the Vessel project as popular, well-attended, comprehensive exhibitions for a public trying to make sense of the patterns of our present day.

Built around these three roles — of Learning, Research, and Archival — the Vessel framework is designed to adapt to any setting or situation. What all Vessels would have in common is a dedication to preserving cultural capability, and a layered, approachable presence adapted to its setting. Many should be built, using many approaches. Some could be public, while mission critical Vessels may be as remote as the Svalbard Seed Vault, or even secret.

Some may be massive as habitats, with others more like sculptures, compact and dense as a room. At the recent Starship Century conference in May, Freeman Dyson envisioned terrarium-like habitats which could seed the vast reaches of space with life. This egg-like approach is hugely inspiring to ponder from the perspective of the Vessel project. Whether urban or remote, extreme habitats or modules on a starship, Vessel is offered as a flexible framework for the long term survival of life’s capabilities.


The Vessel project has several routes forwards. Plans for 2014 include the previously mentioned global survey of existing long-term archival projects, an open design document to help others adapt and evolve the Vessel framework (on which I am already working with a small team of interested artists and specialists), and a Kickstarter for a Vessel- related art project. And, at the invitation of Paul Gilster, we can add to these plans our regular updates on the Vessel project’s progress to the readers of Centauri Dreams. While I explore the nuts and bolts of Vessel’s critical path to an implementation, Nick will help deepen our grasp of the long term potential for a civilization that has chosen to mitigate Xrisk.

Right before Starship Congress, I began an Internship with the Long Now Foundation, working on a project called the Manual for Civilization (See here and here). As the first core collection for their planned Library of the Long Now, a 10,000 year archive, this work will overlap deeply with the Vessel project. So, my own timeline for Vessel is in flux. But if you’d like to collaborate, discuss ways of applying Xrisk mitigation to your own work, or want to help accelerate these efforts, please get in touch. You can register for updates on the Vessel project at

And, you can ask questions in the comments; both I and Nick will do our best to answer.

Our discussion of Xrisk continues tomorrow with Nick Nielsen.


[1] 100 Year Starship. 2011. “The 100-Year Starship Study: Strategy Planning Workshop Synthesis & Discussions” ( Accessed August 2012.

[2] Bostrom, N. “Existential Risk Reduction as Global Priority” ( Accessed August 2013.

[3] Sagan, C. Pale Blue Dot: A Vision of the Human Future in Space (Random House, 1997).

[4] Benford, G. “Saving the library of life,” Proceedings of the National Academy of Sciences 89, 11098-11101 (1992).