Slashdot Mirror
Obama Transition Team Examining Space Solar Power
DynaSoar writes "President-elect Obama's transition team has published for public comment a white paper entitled Space Solar Power (SSP) — A Solution for Energy Independence & Climate Change. The paper was prepared and submitted by the Space Frontier Foundation and other citizen space advocates, and calls for the new Administration to make development of Space Solar Power a national priority. The SSP white paper was among the first ten released by the Obama transition team. It is the first and only space-related white paper released by the team to date. With 145 comments thus far, it is already among the top five most-discussed of the 20-some white papers on Change.gov."
He's also talking about extending human life to 200 years. The guy's a genious. The plan involves releasing $700 billion to a new life extension department headed by Hank Paulson.
"The Technical and Economic Feasibility of Mining the Near-Earth Asteroids
Abstract
Future large scale commercial activities in space will require raw materials obtained from in-space sources rather than from Earth, to overcome the high cost of Earth launch. This paper reviews the prospectiveness of non-terrestrial resources and notes the competitiveness of Near-Earth-Asteroids c.f. the Moon and Phobos or Deimos in terms of accessibility and likely resources. Astronomical work over the last fifteen years has increased the number of known Near Earth Asteroids (NEAs) from about 30 to about 400. Discovery rate of NEAs is now about 50 per year.
Asteroid "geography": NEAs are classified by orbital parameters into Apollos, Amors, and Atens; in addition, the "Arjunas" are the group of small objects in very Earth-like, and therefore very accessible, orbits. Accessibility is defined in terms of velocity requirements (delta-v) for outbound and for return trajectories. Approximately 10% of NEAs are more accessible than the Moon, and maybe 50% of these are likely to be potential orebodies.
Asteroid "geology" has advanced dramatically in the last decade, via spectroscopic and dynamical studies of asteroids and comets, and meteorite studies; reasonable inferences can now be made from asteroid types defined by spectral properties to probable surface mineralogy. Many asteroids may be "volatiles bearing", containing clays, hydrated salts, and hydrocarbons. It also now seems that there are dormant cometary bodies within the population of NEAs. These are likely to contain remnant primordial ices within their cores, making them possible sources of volatiles for future space industry. Resources which would appear to be readily recoverable are thus water and other volatiles, for manufacture of propellant in orbit; and nickel-iron metal, for construction in orbit.
There have been various concepts proposed for mining and retrieval to low-earth-orbit of materials from NEAs, but methods of comparison of the economic feasibility of competing mission concepts are not well-developed. In-situ production at the asteroid of the propellant needed for materials return is an important "enabling" concept. This paper develops methods for comparison of different asteroid mining concepts, and for choosing between various product, process, mission, and engineering alternatives, so as to maximize likely project economic feasibility.
Application of celestial mechanics shows that (i) simple estimates of "global minimum" delta-v can be made; (ii) low-energy opportunities occur at approx 2-yearly intervals, for many NEAs; (iii) long synodic periods militate against multiple-return mining missions; (iv) Earth-return hyperbolic velocity should be kept low; (v) high-eccentricity targets require Hohmann transfers, and a short mining season at aphelion; (vi) low-eccentricity targets may use continuous-thrusting propulsion, and extended mining season. There is a growing subset of targets that are intermittently accessible for an outbound delta-v of under 6 km/s, and offering return departure delta-v under 2 km/sec.
Mining and processing system choices depend on the assumed regolith mineralogy and bulk handling properties, and on the assumed subsurface composition and properties. Process options are (i) in-situ fluidization; (ii) mechanical collection and thermal or magnetic separation; (iii) carbonyl process. Equipment mass estimations for volatiles extraction suggest total processing system mass of less than 5 tonnes for a teleoperated / autonomous miner mission to return 1000 tonnes to LEO.
Sensible and politically achievable propulsion and power system choices are restricted to (i) solar thermal steam rocket; (ii) solar photovoltaic arcjet; (iii) solar photovoltaic massdriver.
As for terrestrial mining projects, the Expectation (probabilistic) value of the Net Present Value is a crucial unifying concept for evaluating competing mission options. By testing system choices for their effect on NPV, one can arrive at