Steps to Space

Still in progress ...

Neil Armstrong's "Giant Leap For Mankind" was one step among trillions, by billions of people for thousands of years. A milestone, but there will be thousands of milestones on the way to a living cosmos. Life found ways to profit (derive benefit from) every step along the path from inert matter to an Earth filled with life; as Earth life's ambassadors to the universe, so will we.

This webpage lists a series of steps we can take to the stars. Some steps are dependent on others, but the ordering presented here is one of many possible ways of sequencing those dependencies.

Some major milestones are:

• worldwide longterm prosperity
• space biology testing
• digital immortality
• server sky
• launch loop
• space solar power
• lunar materials
• complete space industrialization
• space settlement
• taming the solar system
• lunar NEO interception
• a Stapledon-Dyson shell
• preserving life on Earth beyond the Sun's lifetime
• filling the galaxy with life

Some steps to these milestones follow.

Kilogram Server Sky

First experimental thinsats strung together in 250 gram "box kites". Profits from kickstarter sales, chip radiation testing, scientific data collection in the van Allen belt, particularly particle trajectories and energies. See HitchHiker for details.

Radar Server Sky, space debris ephemerides

Thinsat arrays will make excellent transmitters and receivers for 60 GHz radar; hundreds of kilowatts of pencil-beam chirped energy and hectares of receiver area, backed by petaflops of computation and correlation. This permits a complete and precise mapping of space debris to sub-gram object size, allowing space assets to maneuver away from (or intercept) threatening debris objects.

Developing World Data Server Sky in MEO

Petabit data service to the cell towers serving three billion tropical people. The goals are to provide education, global connection, and digital employment opportunities to these people. They will be able to shape the global economy and contribute their cultural wisdom to the world without leaving their families. Worldwide longterm prosperity Server sky thinsats will be cheap enough for them to own as capital goods, providing collateral for credit transactions and assets protected from local corruption. Perhaps 1 terawatt of computation services delivered from 12789 km radius MEO orbits.

Second Generation Server Sky

MEO thinsat orbital stability requires a minimum mass of 100 grams per square meter (in sunlight); however, thinsats can be manufactured thinner than 10 grams per square meter, with on-orbit ballast added to stabilize orbits. Lumps of mass from space debris and retired thinsats are a good source of this mass, providing a profitable path to debris-free orbital space. Assuming 200 watts per square meter (averaged over the orbit, including self-occultation and night-side eclipse), that is 2 kilowatts per kilogram, and 1 terawatt of thinsats would be 500,000 tonnes. That might be composed of 50,000 tonnes launched from Earth, 10,000 tonnes of space debris and recycled thinsats, and eventually, more than 400,000 tonnes of lunar regolith welded into 2 gram ballast blobs.

Cutting up debris into ballast, and the production of regolith bricks, will be the first baby steps towards space manufacturing.

Radiation Belt Remediation by Server Sky

500,000 tonnes and 5,000 square kilometers of metal foil in MEO orbit will Rutherford-scatter radiation belt particles (mostly protons and electrons) into longer pitch angles, trajectories that intercept the upper atmosphere. That will rapidly deplete the belt regions that Server sky orbits through (L=1.8 to L=1.2 or so), creating a low-radiation zone that slowly spread as magnetic storms perturb neighboring belt regions into the depletion zone.

Thinsats will detect particle flux in order to predict and compensate for radiation-induced computation errors - precise time and space mapping of those particle events will generate exabytes of radiation belt scientific data. The van Allen belts will go away, but we will have excellent scientific records of what they used to be.

War-proof Space Assets

Server sky arrays may be disrupted by megaton nuclear weapons blasts within a few kilometers, but the radiation flux from a weapon will be only a year or two worth of natural radiation. The energy and momentum flux from the blast will deposit uniformly across the thinsat and the array, so the thinsats can thermally anneal radiation damage and reassemble as an array. Since radar-mode server sky arrays can compute a precise trajectory and launch source for the weapon, the culprit nation can be identified, isolated, and data-starved back to prehistoric poverty and cannibalism. Out of mercy, I hope a wealthy and civilized world will rescue and re-educate their innocent children, while documenting the brutal self-destruction of their insane parents.

Scientific and Commercial Computation at L4/L5

Humans and automated global stock trading demand fast response times from MEO server sky, but scientific data collection and computation (and the future equivalent of block chain computation) can tolerate 2 second round trip delays, from Earth to the LaGrange points. Inverse-square attenuation at 60 times the distance from the Earth's surface permits 3600 times as much illumination for the same night-sky light pollution as MEO server sky, with rare eclipses rather than 1/6 shading of the MEO orbit. More than 4 petawatts of computation power, 50 times the 80 terawatts of electrical grid energy that a rich and optimized planet Earth of 8 billion people might consume. Orbit stability mass requirements unknown; presuming 2 kilowatts per kilogram as before, that is 2 billion tonnes of thinsat. This will benefit from in-orbit manufacturing, with microchips and beneficiated elements from the Earth, and more common elements (oxygen, silicon, aluminum, iron, sodium, magnesium, and titanium) from the Moon.

Dangerous Biological Experiments in Lunar Orbit

While we can do much with computational biology, artificial lifeforms worry many people. While some worrywarts are ignorant, stirred up by equally ignorant demagogues, peer-to-peer server sky education can cure most of that; as Justice Brandeis observed, It is the function of speech to free men from the bondage of irrational fears. We can reduce real hazards to negligable proportions by testing artificial lifeforms in kilogram-scale experimental labs in lunar orbit, connected with high-bandwidth communication to L4/L5 arrays. Lunar orbits are unstable, they will eventually be perturbed into a surface impact. While we should try to direct these impacts into small "toxic waste dumps" on the Moon, orbital mechanics will prevent this material from ever reaching Earth, while cosmic radiation and Solar UV will add additional safeguards. This may seem like extreme paranoia, but eliminating parts-per-trillion risks to life on Earth is necessary for multi-billion year planetary survival.

As we spread into the solar system, we can move these experiments to inner orbits of Jupiter, inside heavily shielded containers. Nothing can accidentally escape Jupiter's gravity well besides broadcast information.

Stabledon-Dyson Shell

An 50 AU diameter ice substrate statite shell of nano-engineered computation, converting sunlight leaving the solar system into computation and 60 Kelvin infrared radiation. 380 trillion terawatts are available, and this will increase as the Sun evolves.

In the distant future, in construction for perhaps 1 million years. Most of that time will be needed to disassemble Oort cloud objects without vaporizing them. Some of the mass will be ejected from the solar system as targeted interstellar probes, ejecting the excess orbital angular momentum of the source objects.

Portions of the shell will act as an X-ray scattering barrier for the Earth when nearby stars go supernova, while the rest of the statites will turn edge-om to the flux, mimimizing absorbed dose and off-axis scattering. Interstellar expeditions to supernova candidates, monitoring core neutrino flux to measure the elemental composition of the core and predict exactly when the supernova occurs, will be part of the long term strategy for protecting nearby solar systems with life-bearing planets.

Digital Immortality

The Earth is finite. Whether it can support 8 billion people over billions of years, or less, if we choose to have children, we either die or go elsewhere. Meanwhile, the neurons in unmodified human brains do not replicate after development (pregnancy and a few weeks after birth), so even if we keep every neuron alive somehow, we face hard limits on the capacity of those brains.

However, we will someday internalize our digital tools, connecting them directly to our brains, speeding input and output, and more importantly conveying sensory data and adding manipulation capabilities that natural brains lack. Perfect memory, predictive-adaptive telepresence, the list of possiblities are endless, and plenty of early adopters willing to risk their lives and their sanity to try the new technologies first. The rest of us will learn from their mistakes and their successes.

In a few decades, there will be people who are mostly enhancement - as their biobrains decay, their enhancements remain and fill in the gaps, until the biobrains and bodies fail and the enhancements continue. Again, a dangerous and error-prone process, but so evolution, and biological life in general.

The Earth is a hot, corrosive, confined, resource-limited place to keep electronic intelligence; digital personalities will soon escape the Earth and into the abundant resources of the Stady shell.

Because the Stady shell is cold and stable against thermal damage, it can operate with 5x lower power per logical operation than the best possible electronics on the 300 Kelvin Earth. Neural operations are perhaps 25,000 electron volts each, and a "Shannon limit" digital operation might be 0.02 electron volts at 300 Kelvin, so a stady shell operation might be 0.004 electron volts, 1.6e-7 of the energy used by a neural operation. Even with 600 times the power (mostly for signal propagation, error and damage repair), a 20 watt human brain might be emulated with less than 2 milliwatts. There's room in a solar system Stady Shell for 2e29 human-scale minds, enduring for 10 billion years; in the whole galaxy, perhaps 1 billion times more.

There is no need to damage the Earth to do this; indeed, a vast amount of the shell can be devoted to protecting and enhancing the Earth into the distant future. That is 1 digital mind for every 25 living bacterial cells on Earth - even if only a tiny fraction of those minds focus their attention inwards, they can blanket our home planet with enough love and attention to keep it alive for a very, VERY long time.

Launch Loop Technologies

Diamond-coated iron pipes ("rotors") moving in moderate vacuums at 8 to 20 kilometer-per-second velocities can store enormous amounts of energy and momentum, and be deflected by Tesla-scale magnetic fields into loops and structures above the atmosphere. Magnetic attraction is unstable; measurement, computation, and electronic control is required for stability. However, control frequencies range from 1 to 100 KHz, and chips can perform trillions of computations per second, distributing the results over fiber optics 10,000 times faster than the rotor moves.

The vapor-deposited diamond coating will be thicker than diamond hard disk platter coatings, and thinner than tool coatings. This is a well-understood industrial process; the purpose is to reduce "spalling yield" from small particle collisions. The Launch Loop website has much more information.

Terrestrial Power Storage Loops

The energy densities of fast moving rotors are high; an iron rotor (density 7870 kg/m³) moving at 8000 meters per second stores 70,000 KWhr/m³, the output of a gigawatt power plant for 4 minutes in about $100 worth of iron.

A practical exaggeration - the iron will be formed and machined into bars or pipe perhaps 5 to centimeters in diameter, and positioned with electromagnets and above the track and inside the turns. The electromagnets, sensors, vacuum containment and tunneling to hold the rotors will be far more expensive.

Small loop ring velocities are limited by magnetic field strength, rotor mass, and turn radius. A 9 kilogram per meter, 5 centimeter diameter round rotor in a 1 Tesla control field moving at 8000 meters per second has a turn radius of 14 kilometers. If the rotor and tunnel are in a racetrack oval, two "D" magnets at the end with 100 kilometers of track between the ends, the total length of the rotor is 288 kilometers, the mass is 2600 tonnes, and the power storage capacity is 8.3e13 joules, or 23 gigawatt-hours. Many rotors can share most of the same tunnel, though care must be taken to prevent "fratricide" in case one of the loops fails catastrophically. Occasional diverters and "mass dumps" along the path will allow one power loop to fail without damaging neighbors.

The rotors are NOT under high tension; the stiffness of the pipe simplifies the control system in the D magnets. Energy is added and subtracted with linear motors, whose losses are proportional to thrust, not speed. Linear motors can be 99.9% efficient at high velocities.

8000 meters per second is a "magic" number; an 8000 m/s rotor following the curvature of the Earth is in orbit. Forces will increase to full gravity as power is removed and the loop slows down. The upper magnets must be strong enough to hold up the rotor against full gravity, and plus or minus perhaps 5 gravities in case of an earthquake, with accommodations for shear faults along the path.

Small systems are not nearly as efficient and cost effective; if the turn radius is small, the maximum speed is limited and the energy density is too. On the other hand, rotors moving much faster than 8000 meters per second must be held down to follow the Earth's curvature, dissipating power in deflection magnets along the entire length of the straightaway. Above 20,000 m/s, the spalling yield of a loose atom in the plenum between rotor and track can exceed unity, leading to a hypervelocity spalling cascade. This is the reason for the diamond coating - diamond is very strong, and carbon atoms are relatively light, compared to iron or steel.

A better location is deep underwater, far from shore at the edge of the continental shelf. The water provides mass shielding. Floats can hold the rotor above the sea bottom, anchored with cables that can be adjusted for shear faults. Very large power loops can encircle the Pacific Ocean, injecting or withdrawing power from the western or eastern hemispheres at appropriate times of day. Indeed, since the turn radii are so small, the rotor can be made evem more massive compared to the deflection magnets. The power used for normal deflection can be a tiny fraction of stored energy, so the power loop can store energy efficiently for years. An 8000 m/s Pacific ocean loop perhaps 30,000 km in circumference and massing 100 kg/m can store 9.6e16 joules, 36 gigawatt-months. 1000 such loops could supply the northern hemisphere with 9 terawatts for 4 months.

Rotor dumps can boil sea water mixed with iron vapor. The dissolved iron might cause a small algae bloom, increasing fish populations. Hopefully, these expensive events will be rare.

These are huge systems, though the cross sections are a fraction of a meter. They are assembled out of millions of identical units, so they can be mass produced and deployed robotically. They can store peak load from summer overproduction of terrestrial solar photovoltaic farms, and deploy that power in winter for heat pumps in hundreds of millions of homes.

Powerloop is a profitable way to earn money, develop technology and manufacturing capability, and provide power in midocean.

Earth Launch Loop

The power can be used for launch loops near the equator. The launch loop stores power and momentum in a 3 kg/m rotor moving at 14,000 meters per second. This is faster than orbital velocity, so considerable force is required to hold the rotor in a curve around the earth, supporting about 7 kg/m of stationary track and stabilization cables to the surface. A sled with long rails of magnet can extract momentum and energy from the rotor (slowing it a bit, and heating it a lot), and push a 5 tonne space vehicle up to escape velocity.

The

Lunar Launch Loop