Tuesday, October 23, 2012

The Celestial Spheres

About five kilometers above sea level, we reach the limits of the Settlersphere, the highest permanent human settlement.

The Personsphere is currently defined by the orbit of the International Space Station, 330 to 410 kilometers above sea  level. It has been continuously occupied since November 2, 2,000. Aboard this enormous spacecraft humans live and play the flute.

The Profitsphere stretches to about 35,786 km above sea level. Within this zone unsentimental corporations can make a profit selling services to individuals and corporations: satellite communications, remote sensing and space tourism. It actually reaches a bit further than geostationary orbit: the Russians have found that Molniya orbits with an apogee of up to 40,000 kms have some advantages for serving northern latitudes.

Further out is the Landersphere, which currently reaches to Mars. Within it we have two operational rovers on the surface of an alien world, poking and prodding and sending back photographs.

Further still is the Inner Proxysphere, where we have inserted orbiters  to observe the worlds below over the course of many years. It reaches out to Saturn and down into the Sun's gravity well as far as Mercury. In Mars orbit we have a flotilla at work.

Finally, there is the Outer Proxysphere. Voyager 1 and 2 completed their flybys of the outer planets decades ago. They now fall outwards towards the stars. They will faithfully observe and report back as long as their power lasts. Voyager 1 is now over 18 billion kilometers from the sun.

The New Horizons spacecraft crossed the orbit of Uranus in March of 2011. It will fly by Pluto and follow the Voyagers outward.

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