Robotic in orbit assembly and laser propulsion could enable vast increases in space capability while not significantly changing the world civilization energy budget.
Robotic and additive manufacturing could enable massive frames and massive solar power arrays
Tethers Unlimited is currently developing a revolutionary suite of technologies called “SpiderFab” to enable on-orbit fabrication of large spacecraft components such as antennas, solar panels, trusses, and other multifunctional structures. SpiderFab provides order-of-magnitude packing- and mass- efficiency improvements over current deployable structures and enables construction of kilometer-scale apertures within current launch vehicle capabilities, providing higher-resolution data at lower life-cycle cost.
They have received a $500,000 phase 2 NASA NIAC contract, which follows a $100,000 phase 1 contract to develop the technology.
100 of the 2100 cubic meter stations would be about $50 billion without any volume discount.
100 of the 6000 cubic meter station might be about $100 billion.
Launching with reusable rockets would be about $1 billion.
Say $10-20 billion for Spiderfab constructed solar power dish arrays and structure.
There would need to be $10-20 billion for operations.
It would be less than the cost of the international space station.
Spiderfab, Expandable stations and Reusable rockets could make affordable large scale orbital colonization
A ten thousand person colonization space ship design is proposed with a focus on how the community and living spaces should be designed. People are assigned area with the density of the city of Seattle and standard mixed use living areas. Everyone has 50 square meters of living space. There is agricultural and other green areas.
Solar pumped lasers have long been a technology which are an important enabling option for space based solar power and for beam powered propulsion for interplanetary and interstellar applications.
Recent work has looked at laser starways where laser power is beamed 70 Astronomical Units
There has been earth based progress towards using solar powered lasers for Magnesium production. Having a profitable industrial application to fund and drive and scale the development of solar powered lasers is good news for accelerating solar powered lasers for space applications. There was a 2012 research paper that also looked at solar powered lasers.
They are scaling to 1 megawatt of solar collection and 30 watts of laser per square meter of collection area. A space based system could have 60 watts of lasers since there is no atmosphere blocking sunlight. Space based being application would then need another fresnel lens to focus the lasers for long range beaming.
Other References on Power Beaming
There was a 2010 patent on space based solar power beaming
There was also the Mankin SPS Alpha space based solar power design.
There was updated presentation on near term solar sails at NASA FISO (Future in Space Operations) by Bruce Campbell. Nextbigfuture also reviews the Spiderfab robotic assembly in orbit capability which could enable 1 kilometer diameter solar sails for dramatically superior space capabilities. A rudimentary interstellar solar sail is possible with a 400 meter diameter. So a 1 kilometer solar sail would have 6.28 times the area of the 400 meter sail.
Spiderfab in orbit assembly of kilometer scale solar sails and laser focusing elements
Spiderfab will use robots to assemble structures in space.
Spiderfab on orbit assembly can reduce the mass of space structures by 30 times.
This will enable solar power arrays with over 120 watts per kilogram. This is needed for fast solar electric interplanetary missions.
Spiderfab can also enable solar sails that are over 1000 meters in diameter.
Laser propulsion to significant fractions of light speed should be possible within 30 years
Philip Lubin describes his approach to achieving laser driving spacecraft propulsion in the near term
100kg robotic craft could be sent to Mars in 3 days
1kg could go overnight to Mars
50-100 GW could send a wafercraft to 30% of the speed of light and i would involve 10 minutes
A system that is about 100 times the mass of the space station would be able to launch such missions to Mars or interstellar wafercraft.
So fully reusable Spacex rockets would be able to affordably launch such a system into space in the 2020s.

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.
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