Yesterday’s scale-of-space post gathered comments pretty quickly, at least in part due to my own failure to define my terms properly… but it’s a reminder that space still stirs up the imagination like little else, whether one’s imaginings be favourable or dismissive.
And so, here’s some more imagination fuel! As mentioned before, space seems to be clambering back onto the futurist Zeitgeist train of late – a response to the grim economic certainties of the foreseeable future (such as it is)? We all need something to reach for in our dreams, I guess… and if you’re gonna reach, why not stretch to your utmost? The Technology Applications Assessment Team of NASA’S Johnson Space Centre aren’t limiting themselves to anything less than affordable and achievable concepts for manned deep-space missions [via MetaFilter]:
… six technology applications that they are focusing on: satellite servicing, ISRU on the Moon, a SBSP demo, solar electric propulsion vehicle, propellant depots, and the Multi-Mission Space Exploration Vehicle (MMSEV).
The Nautilus-X MMSEV is intended as a reusable in-space vehicle for cis-lunar and deep space missions. It would offer a sizable volume to sustain a crew of six and hold enough supplies to sustain a two year mission.
Radiation mitigation strategies, such as creating safe zones with water and H2-slush tanks, are being investigated. It is “capable of utilizing variety of Mission-Specific Propulsion Units [integrated in LEO, semi-autonomously]”.
Most strikingly, it would include a ring centrifuge to provide partial gravity for maintaining crew health.
Caveat: “affordable” is a very relative term:
Estimated cost and time: “$3.7 B DCT & Implementation 64 months”
Ouch. Still, pipedreams they may be, but every human achievement was an act of the imagination first, right? But uninformed imagination is just, well, making stuff up… so get yourself over to Centauri Dreams and check out a suggested reading list for people interested in the possibilities of interstellar travel.
Last but not least, and in the name of providing at least one answer to the “sure, we could go there, but what’s the point?” retort, Brian Wang of Next Big Future has excerpts from (and a link to) a speculative PDF report on human population curves after escaping the hard resource limits of Gaia:
NASA studies (Johnson and Holbrow, 1977) confirmed that it was technically possible to build large vista space habitats in free space, essentially anywhere in the solar system (out to the asteroid belt if only solar power were used) with up to about 4 million people in each. In O’Neill’s habitat model the space citizens would live on the inside surfaces of radiation shielded spheres, cylinders, or torus’s which would be rotated to provide Earth normal gravity. The prohibitive Earth launch costs for these massive structures could be off set by using lunar and asteroid materials. Construction of (Glaser, 1974) space solar power satellites by the space colonists would make the project economically viable. Economic break even for the O’Neill-Glaser model was calculated to be about 35 years after which very large profits would be incurred. The result would have been a solar powered Earth and millions of people living in space by the beginning of the twenty first century.
Recently the O’Neill-Glaser model was recalculated (Detweiler and Curreri, 2008) to find the financially optimum habitat size. For simplicity only the habitat size was changed and the financial costs of money and energy updated, while keeping the original 1975 technological assumptions. In order to make the model financially viable the workers must live in space, space resources must be utilized and the community must build Space Solar Power Satellites, SSPS. A net present value plot showing the original calculations (Johnson and Holbrow, 1977) building 10,000 person torus habitats compared to calculations for the habitat size that optimizes costs. Starting the program with smaller habitats (64 – 2000 persons) results in peak costs that are reduced by about 75 percent and one third reduction in time for financial break even (year 25 for the optimized model).
Wildly speculative? Sure it is. So was putting a man into orbit, and not all that long ago.