Final Frontier 8: Geosynchronous Orbit

With the Hubble Repair Mission flying this week, the Kepler Observatory beginning its data collection to find earth-like planets around other stars, and the rebirth of Star Trek, I am spending the week discussing my own vision of the future – a future that will require the development of space.

I have described transportation to low-earth orbit, some of the concerns of both physics and economics that will govern what that low-earth station is like, and some of the physics of space flight that are at odds with our earth-based intuitions. Next, I move out to geosynchronous orbit.

Four crewed communications centers in geosynchronous orbit can do all of the work currently being done by all of the communication and earth-monitoring (e.g., weather) satellites currently in Earth orbit. Well, actually, it can be done with three, but four makes things a little easier.

This would have a number of economic advantages. The first of these is that the equipment can be monitored, maintained, and upgraded. There currently is no way to maintain, repair, or upgrade a current communications satellite. Once it launches it is on its own. If it breaks, it is broken. If new technology comes along that would upgrade performance, the only option is to launch another satellite.

There are a number of forces acting on a satellite that push and pull it out of position. Satellites require fuel for station-keeping. Once the fuel runs out, the satellite starts to drift out of geosynchronous orbit.

These problems cease to exist if the communications equipment is placed on a station in geosynchronous orbit, with a crew who can maintain, repair, and upgrade that equipment.

There is a problem in that the closer two receiving antennae are, the more important it is that different broadcast antennae use different frequencies. It may be necessary to move some communications equipment away from the station – either ahead of the station or behind it in the same geosynchronous orbit. Yet, even here, there would be an improved ability to bring the satellite into the crewed station for repair and refit.

This might also be the best place to build solar-power satellites – huge stations for capturing the sun’s power and converting it into energy (which, itself, can be beamed to other stations or down to Earth). These would be massive constructions, with acres upon acres of sunlight-collecting potential.

Each geosynchronous station will need to have its own space baton – a long tunnel with a module at each end that spins in space like a twirling baton. People will be able to (required to) work and exercise on the modules at the end of the baton to prevent muscle and bone decay in an environment that simulates Earth's gravity.

However, there would be no need to worry about major (and expensive) maneuvers to re-boost the station back to a higher orbit. The station will drift over time, but this drift can be taken care of with less significant efforts.

On the other hand, the inhabitants of this station will need something that people in low earth orbit would not need – a massive shelter to protect its citizens from the radiation of a solar flare. The earth's magnetic field protects its inhabitants (us) from the harmful effects of intense radiation of a solar flare. Anything in low earth orbit is close enough to share in that protection. However, it would not protect anything in geosynchronous orbit.

Whenever a solar flare releases its energy in the direction of the Earth, the inhabitants of space stations far away from earth will need to get behind some heavy shielding. There will not be a mad scramble to do this – there will be plenty of warning. But it will have to be done, meaning that the massive shelter must be ready for them to occupy.

If this massive shelter is built at the end of a space baton (giving the occupants both simulated gravity and radiation protection), its mass will want to pull the baton apart. Try twirling a bowling ball at the end of a rope around your head. Consequently, the shelter may be built in a weightless zone. The occupants can have simulated gravity or radiation protection but not both at the same time.

Because these orbits are economically useful, and because objects in geosynchronous orbit do not suffer nearly as much decay as objects in lower orbits, this may well be where much of the heavy space construction takes place. Whereas the low-earth-orbit station serves as the port for our growing space civilization, geosynchronous orbit may well be the place for heavy industry.