Centauri Dreams returns with an essay by long-time contributor Alex Tolley. If we need to grow a much bigger economy to make starships possible one day, the best way to proceed should be through building an infrastructure starting in the inner Solar System and working outward. Alex digs into the issues here, starting with earlier conceptions of how it might be done, and the present understanding that artificial intelligence is moving at such a clip that it will affect all of our ventures as we transform into a truly space-faring species. Under the microscope here is a company called SpaceFab, as Alex explains below, and the potential of ISRU — in situ resource utilization. Emerging out of all this is a new model for expansion.

by Alex Tolley

“Asteroid Facility” – Syd Mead

To sail the heavens and reach the stars is extremely expensive.  With the technologies we can currently envisage, Earth’s GDP will need to be orders of magnitude larger to support a starship program.  Unfortunately, the Earth is likely to hit environmental and economic limits well before we reach the necessary size of a starship building GDP.  One solution is for humanity to expand into the solar system to grow the economy with the vast resources available out there [5]. Science fiction novels are replete with tales about self-reliant belters extracting wealth from the asteroids, while followed by adventurers, gold-diggers and chancers, that recapitulate the myths of the “Old West” and the US’ manifest destiny [1].  

Space Habitat – John Berkey

By the late 1970s, establishing space colonies and selling solar power to Earth [2] was the idée du jour. Allen Steele popularized that vision, regaling us with stories of men and women living and working on the high frontier [3].  In reality, the cost of transporting and housing space workers is astronomical compared to those of ocean rig workers whose jobs those high-frontiersmen emulated.  An economy supporting a wealthy, post-scarcity civilization living throughout the solar system and able to support starship exploration became more fanciful, and we focussed on scaling back our starship ambitions with 1-gram, laser-propelled, sail ships that might launch half a century hence.

Exploring the Asteroids – Robert McCall

While the prospects for humans in space dimmed somewhat, a renewed flowering of developments in AI and robotics burst onto the scene with capabilities that astonished us each year.  On the endlessly orbiting ISS, while astronauts entertained us with tricks that we have seen since the dawn of spaceflight, autonomous robots improved by leaps and bounds.  Within a decade of a DARPA road challenge, driverless cars that could best most human drivers for safety appeared on the roads.  Dextrous robots replaced humans in factories in a wide variety of industries and threaten to dramatically displace human workers. DeepMind’s AlphaGo AI beat the world’s champion GO player with moves described as “beautiful” and well within the predicted time frames.  In space, robotic craft have visited every planet in the solar system and smart rovers are crawling over the face of Mars.  A private robot may soon be on the Moon.  In orbit, swarms of small satellites, packing more compute power than a 1990 vintage Cray supercomputer, are monitoring the Earth with imaging technologies that equal those of some large government satellites. On Earth we have seen the birth of additive manufacturing, AKA 3D printing, promising to put individual crafting of objects in the hands of everyone.  

What this portends is an intelligent, machine-based economy in space.  Machines able to operate where humans cannot easily go, are ideally suited to operating there.  Increasingly lightweight and capable, and heedless of life support systems, robotic missions are much cheaper..  How long before the balance tips overwhelmingly in the machines’ favor? Operating autonomously, advanced machines might rapidly transform the solar system.

In a previous post, A Vision to Bootstrap the Solar System Economy” [4], I looked at an academic paper that laid out an idea of self replicating robots that would start harvesting lunar resources and eventually expand operations out to the asteroid belt.  The power of exponential growth to bootstrap such a system was clearly evident, allowing a relatively tiny investment to create a huge manufacturing capability of staggering size within a short time with growth rates far exceeding our current human-based economies.  An interesting idea and vision, but was anyone going to consider developing a business using that approach? A new company, SpaceFab, shares a similar vision.  The founders want to create a fleet of mining and fabrication robots that will extract raw materials from the asteroids to create refined commodities and products in space, including building more robot miners and fabricators.  A grand vision, but how do they envisage it being done?

While the original idea of asteroid mining was to extract the non-volatile resources, especially the high value platinum group metals [5], more recently the focus has shifted to volatiles, primarily water, for life support and chemical rocket fuels.  SpaceFab however, prefers the extraction of the more abundant iron and nickel, whose current value in space is principally their launch cost. Their argument for this focus is twofold.  Firstly, water is relatively rare in most near Earth asteroids (NEA) and therefore likely to be more difficult to extract from those bodies.  While common in asteroids beyond the frost-line or in dead comets [10], the delta v cost is high and journey times much longer.  Conversely, metals are far more accessible inside the frost-line with NEAs, reducing both the cost to acquire these metals and the mission cycle time.  Secondly, SpaceFab is looking to extract iron and nickel using simple, lightweight and low-cost processes like magnetic collection of material, and induction heating to melt and refine the metals.  Their view is that the path to profitability is faster with this approach than prospecting and extracting volatiles.

The OSIRIS-REx mission is NASA New Frontiers mission to return a sample of an asteroid (101955 Bennu) to the Earth. Mission cost is approximately $800 million (excluding the launch vehicle.).  – Lockheed Martin

SpaceFab believes that they might get a sample return mission to an M-type asteroid within 10 years and a mining craft 5 years later.  Their design target is for a craft just 1 MT in mass (about the same size as OSIRIS-REx), and consists of an ion engine, rock scraping tools for extracting material,  and some form of electrical induction heating to produce refined ingots.  When sufficient extraction is achieved those refined ingots could then be used as feedstock for space manufacturing.   While apparently ambitious, the concept of small craft to mine asteroids has been developed by Calla, Fries and Welch and was presented in two papers at the IAC in 2017.   Their craft were designed to be less than 500Kg.  Water in close by NEAs was their objective based on their analysis of extraction methods which indicated using microwave thermal heating.  Teleoperation from Earth was assumed and therefore an NEA within 0.03 AU was preferred.  The small size combined with a swarm model for redundancy was the most economically modeled approach to provide a large and early return on investment [15,16].For robotic craft  on deep space missions, high Isp electric engines reduce costs, as the lower propellant mass means lower launch costs.  To keep costs low, SpaceFab intends to use off-the-shelf ion engines that may be augmented by their ion accelerator technology (patent pending) that they claim boosts Isp several fold.  With the Dawn mission spacecraft’s NSTAR ion engine having an Isp of 3100s, Spacefab might hope for an augmented Isp of up to 10,000s. The addition of this accelerator unit and the solar panels to power it should increase the mass ratio performance of the craft.

So far SpaceFab’s approach seems similar to other schemes to mine asteroids. Where SpaceFab’s vision really differs is the use of ISRU (in situ resource utilization) for construction of onsite mining and fabrication tools. Rather than hauling out machine tools to an asteroid to extract and fabricate components, SpaceFab plans to reduce the mining craft’s mass, and therefore cost, by building many of the machine tools for mining and fabrication using local resources.  It is just one step further to replicate the whole craft.  This model of self replication of much of the mass of the machines is similar in concept to the robot bootstrapping paper and promises to open up exponential mining and fabrication possibilities, while making the owners quite wealthy.

Most asteroids are too far away to allow teleoperation of the sort that would work on the Moon or with close NEAs.  This rules out complex manufacturing guided by human controllers.  The intelligence needed to prospect, mine and process ores must be local.  Beyond some human oversight, these robot mining craft and fabricators will need to be highly autonomous.  This requires advanced AIs. While we are not close to that goal today, the rapid pace of development of AI software and specialized chip hardware promises to make this a reality sometime in the projected time frame.  Such craft will be able to navigate to a selected asteroid, prospect it, extract and refine metals, and then fabricate machine tools and manufacture components. SpaceFab believes that such craft could even provide a “manufacturing on demand” service in space.  On Earth we have seen the birth of additive manufacturing, AKA 3D printing, promising to put individual crafting of objects in the hands of everyone.  The technology is already being tested on the ISS to reduce the number of spare parts that must be shipped.  

Fabrication, even self-replication, is no longer a science fiction concept.  Nasa has a “FabLab” program to investigate the best ways of using that technology to facilitate spaceflight as a result of its success with 3D printing experiments on the ISS. Neil Gershenfeld’s lab at MIT has designed a method of robotic self-replication suitable for use in space.  The current proposed system can fit inside a CubeSat [14].  The basic technologies needed for SpaceFab’s vision are already in place, just requiring further development.

The eventual goal of robot miners and fabricators producing commodities and goods at a fraction of today’s prices, via massive supply expansion, may face some short term obstacles.  Low launch costs spearheaded by NewSpace companies like SpaceX could make placing raw materials in space cheaper than space mining, for cis-Lunar infrastructure.  However, space fabrication of components in situ is a useful goal, regardless of the raw material source. In the 1980s, K. Eric Drexler intended to manufacture ultra-light, aluminum solar sails in space. T. A. Heppenheimer described manufacturing trusses for solar powersat arrays using relatively dumb, machines bending and welding rolled sheets of aluminum. Grumman Aerospace had a working prototype “Composite Beam Builder” by the time Heppenheimer’s book [5] was published.  More recently, NIAC has funded space fabrication projects using more sophisticated robotic builders.  

At some point, regardless of cost, the sheer volume of resources for expanding the economy will require sourcing from space to overcome the Earth’s limitations.  Robotic mining and fabrication will then become the norm.  As with newly industrializing Earth-based economies, initial fabrication may be for simple, low value added, bulk commodity products, but eventually as capabilities increase, higher value added manufactures will be possible.

Although initially limited by key components like advanced computer chips, over the long term, self-replicating craft would evolve into Von Neumann replicators.   Philip Dick invented the term autofac for factories that could construct themselves from seeds and self replicate [6].  While Von Neumann machines are just self replicators, autofacs also generate outputs, much as honeybee colonies also produce excess honey.  Such self-replication and fabrication infrastructure could produce a vast range of products for the solar system economy.

SpaceFab’s Waypoint Telescope – engineering mockup.

To reach the goal of space mining and manufacturing without the deep pockets of a Deep Space Industries or Planetary Resources, SpaceFab intends to enter the orbital satellite observation market.  They have designed a low cost, high resolution (1 meter ground resolution) telescope that can be used both for astronomical and Earth observation purposes, using a variety of imaging sensors and filters that offer the range of imaging outputs suitable for both markets. Currently they are crowd-funding their initial prototype telescope which will be followed by a flight ready telescope for a 2019 launch.  By launching a fleet of such telescopes, they expect to penetrate this market by offering the lowest price imaging and analysis services.

This observation service would then produce the profits needed to develop the asteroid mining craft and bootstrap the space fabrication business. Interestingly, SpaceFab currently has no intention of using these observation satellites to prospect for suitable asteroids as DSI intends, but rather to use existing information to enable a mission to an M-type NEA.   As this information will not be detailed enough for detecting higher quality ores, the spacecraft will need to be smart enough to do their own prospecting on arrival at an asteroid.  SpaceFab speculates that in the near term, the value of fairly pristine asteroidal material may be higher for research than its commodity price and may offer a faster path to early profitability.

Once mature, self-replicating fabs promise a future that has vastly expanded horizons and  implies a post-scarcity economy.  Once such seed factories become ubiquitous, there is no reason why they could not venture to other solar systems and replicate there.  Even if slow, perhaps travelling at 1/100th c, they would reach the nearer stars in half a millennium, creating all the materials and habitats for humans to occupy.  This is the model that Asimov’s “spacers” envisaged for themselves [7], their robots preparing the way for them to follow.  The colonization process would be with a wave of machines preparing star systems for the following human starships.

It is a dazzling future to contemplate if it unfolds this way.


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