Currently humanity can control about 20 terawatts and this is increasing at 3% per year. As an unintended by-product there is slow climate change over the course of many decades to centuries. There have been many proposed plans to terraform Mars, but those are to bombard with objects from the asteroid belt or add bioengineered organisms to generate warmth and a thicker atmosphere with oxygen.
Consider the sunlight received every second by planet Earth, from the Sun. About 1.4 kilowatts of energy for every square metre directly facing the Sun – all 125 trillion of them. A total power supply of 175,000 trillion watts (175 petawatts), which is about 8,750 times more than the mere 20 terawatts human beings presently use. Earth receives a tiny fraction of the total – the Sun radiates about 2.2 billion times more, a colossal 385 trillion trillion watts (385 yottawatts).
Controlling 17.5 petawatts is one tenth of Kardashev level one. Ten billion times more than 175 petawatts is Kardashev level two where civilization controls all the power of the Sun.
A giant interstellar laser sail, massing 2,500 metric tons and using laser power of 5 petawatts, which accelerates the laser-sail starship 1 gee for 190 days to achieve a cruise speed of half light-speed or 150,000 km/s. 17.5 petawatt means you could launch 6 of them each year.
Large lensing structures may not be something of the far future. There was a 2007 NASA NIAC study for making large bubbles in space. Devon Crowe of PSI corporation made a study for making large space structures from bubbles that are made rigid using metals or UV curing.
A single bubble can be 1 meter in earth gravity, 100 kilometer in low earth orbit or 1000 kilometers in deep space. Foams made of many bubbles could be far larger in size.
The size of a 1000 kilometer bubble is nearly the size of Charon, the moon of Pluto. Charon is 1200 kilometers in diameter. Saturn’s moon Tethys is 1050-1080 kilometers in diameter Ceres the largest object in the asteroid belt is 970 kilometers in diameter. A single tesselation foam (like in the picture) of 1000 kilometer bubbles would be about the size of Earth’s moon. A Penrose tesselation like the one in the picture of 1000 kilometer bubbles would be in between the size of Neptune or Saturn. A Tesselation foam of 100 kilometer bubbles in earth orbit could form an object the size our existing moon or larger.
Metal can be evaporated to coat the inside of the bubble for reflective sails and telescopes.
At the end of this article I will also discuss spiderfab lens construction.
Brute Force Teraforming described by Adam Crowl
Releasing oxygen from Martian rocks requires melting the rock, usually composed of about 30% oxygen, and breaking the chemical bonds. What results is a melt of mixed metals, like iron, and semi-metals, like silicon, and oxygen gas, plus hardy compounds like aluminum oxide. For every kilogram of oxygen released, about 30 megajoules of energy are needed. Earth-normal oxygen levels require a partial pressure of 20 kilopascals (20 kPa), which means a mass of 5.4 tons of oxygen for every square metre of Martian surface – 775 trillion tons in total. The total energy required is 10 yottajoules. Adding 80 kPa of nitrogen, like Earth’s atmosphere, requires mining the frozen nitrogen of Neptune’s moon Triton, doubling the total energy required. Shipping it from Saturn’s moon, Titan, as Kim Stanley Robinson imagines in his “Mars Trilogy”, requires 8 times that energy, due Saturn’s less favorable gravity conditions. Warming Mars to Earth-like levels, via collecting more solar energy with a vast solar mirror array, means collecting and directing about 50 petawatts of solar energy (equal to about 10 laser-sail starships). Before we use that energy to gently warm Mars, it can be concentrated via a “lens” into a solar-torch able to burn oxygen out of Mars’s rocks. With 50 petawatts of useful energy the lens can liberate sufficient oxygen for breathing in a bit over 6 years. Using 17.5 petawatts would require about 18 years.
The final task, creating an artificial magnetosphere, is puny by comparison. A superconducting magnetic loop, wrapped around the Martian equator, can be used, powered up to a magnetic field energy of ~620,000 trillion joules (620 petajoules), by about 12.4 seconds of energy from the solar-mirrors. This is sufficient to create a magnetosphere about 8 times the size of Mars, much like Earth’s.
To terraform the other suitable planets and moons of the Solar System requires similar energy and power levels. For example, if we used a solar-torch to break up the surface ice of Jupiter’s moon, Europa, into hydrogen and oxygen, then used it to ‘encourage’ the excess hydrogen to escape into space, the total energy would be about 8 yottajoules, surprisingly similar to what Mars requires. The nitrogen delivery cost is about 6 yottajoules, again similar to Mars. Ongoing energy supply would be 10 petawatts – two starships worth.
Further afield than the Inner System, or even the Outer Planets, is the Oort Cloud, a spherical swarm of comets thousand to ten thousand times the Earth-Sun distance. According to current theories of how the planets formed, there were thousands of objects, ranging in size from Pluto to Earth’s Moon, which formed from the primordial disk of gas and dust surrounding the infant Sun. Most of these collided and coalesced to form the cores of the planets, but a significant fraction would have been slung into distant orbits, far from the Sun. According to one estimate, by astronomer Louis Strigari and colleagues, there are 100,000 such objects for every star.
The technology to send a laser beam to a starship accelerating to half light-speed over thousands of Earth-Sun distances opens up that vast new territory we’re only just beginning to discover. For example, if a laser is able to send 5 petawatts to a laser-sail at 1,000 times the Earth-Sun distance, would be able to warm a Pluto-sized planet to Earth-like temperatures at a distance of a light-year.
Making giant lenses and mirrors of different shapes could direct concentrated sunlight to desired locations in the solar system. More than one lens or mirrors in multiple locations seems like a feasible task.
The optics to achieve what I have proposed would not be trivial even given the feasibility of very large lenses and mirrors of various shapes and properties. German rocket scientist, Hermann Oberth suggested a massive space mirror in orbit to focus light onto the earth to destroy cities.
Oberth thought it might take ten to fifteen years to assemble a complete mirror at a cost of $3 billion. The pressure of sunlight on the vast surface would be used to maneuver it in orbit, with steering accomplished by adjusting the angles of the individual mirrors.
Oberth believed a nearly 5000-square-mile mirror would create a bright, heated “spot” on the earth’s surface about 2000 square miles in area. This heat and light, he admitted, would be “no stronger than that normal at the equator.” But, he went on to say, if “the mirror were double the size mentioned…the irradiation would be four times as strong…The temperature on the surface…would be 392°F.” Maybe not enough to melt cities and blow up battleships, but certainly enough to give one pause for thought.
It may end up being easier to make a massive array of lasers to transmit the energy over the large distances. Physicist and professor Philip M. Lubin, and Gary B. Hughes conceived DE-STAR, or Directed Energy Solar Targeting of Asteroids and exploRation, as a realistic means of mitigating potential threats posed to the Earth by asteroids and comets. Lubin and Hughes calculated the requirements and possibilities for DE-STAR systems of several sizes, ranging from a desktop device to one measuring 10 kilometers, or six miles, in diameter. Larger systems were also considered. The larger the system, the greater its capabilities. DE-STAR 2 –– at 100 meters in diameter, about the size of the International Space Station –– “could start nudging comets or asteroids out of their orbits,” Hughes said. But DE-STAR 4 –– at 10 kilometers in diameter, about 100 times the size of the ISS –– could deliver 1.4 megatons of energy per day to its target, said Lubin, obliterating an asteroid 500 meters across in one year. Larger still, DE-STAR 6 could enable interstellar travel by functioning as a massive, orbiting power source and propulsion system for spacecraft. It could propel a 10-ton spacecraft at near the speed of light, allowing interstellar exploration to become a reality without waiting for science fiction technology such as “warp drive” to come along, Lubin said.
Spiderfab lens construction
Spiderfab will use robots to assemble structures in space.
Spiderfab on orbit assembly can reduce the mass of space structures by 30 times.
Spiderfab can also enable solar sails that are over 1000 meters in diameter possibly even from single launches of say a Spacex falcon heavy or the planned larger Spacex Mars colonization rocket. Reusable large Spacex rockets could rapidly and relatively cheaply enable massive mirror and lens arrays in space. If they were placed near Mars they would focus ten times the light. The solar torch for terraforming would not need to be that precise.
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.