07 March 2008

Two worldviews for the price of one?

It seems that the likelihood of habitable extraterrestrial planets just took a big leap.

But before you Sci-Fi Nerds Throw a Party…

To get there on any terms, we would need a spacecraft physically capable of surviving intact through the entire acceleration regimen of the trip and withstanding the rigors of the journey¹, while still being able at the end of the trip to operate its sensor suite and send a minimum of a few megabytes of data at a level of power sufficient to supply clear reception at the end of a 4.3 light year trip. Finally, the first such ship must be able to make the outgoing trip in less than fifty years, which is the longest travel time we could obtain without running the risk that a subsequent spacecraft capable of overtaking it could be designed and built. To attempt any such journey before those basic conditions would be met would be a colossal waste of resources.

To sum up the numbers

The conditions laid out above result in the following specifications:

  • One to two tons of payload
  • Sensor suite, data storage, and EM transmitter components capable of operating intermittently during fifty years of exposure to wide variations in temperature and exposure to high-energy particles
  • Both of the above joined to a propulsion system capable of maintaining an average speed of 93 million kph during those same fifty years, and decelerating to a capture velocity at the end of the journey

Such a system is possible in theory, though probably not practicable unless the infrastructure to build it can be developed in orbit. Meanwhile, three additional conditions must be met:

  1. The engineering of such a system must be made possible through advancements in propulsion and materials tech;
  2. The target planet(s) must be known to fulfill basic conditions of habitability such as atmosphere, surface gravity, surface temperature regime, and ambient radiation levels in advance (otherwise, we’re better off confining exploration to our own solar system); and
  3. Perhaps hand in hand with the research done to meet the second condition, the spacecraft design must be flown and refined several times before the full mission is attempted.

Such a program would offer a second piece of good news to follow on discovery of habitability: the technologies developed to fulfill the first mission could in turn be adapted to the needs of colonizing any habitable planet found.

Something tells me that as a species we’ll be lucky to accomplish all of these tasks within our lifetimes, and almost as lucky if we don't manage to louse our own planet beyond a state of easy habitability in the meantime.

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