Tag Archives: Arcturus

Slowtrain to Arcturus

I was just re-reading the start of this. I really think that sequel is calling…


From Remote probe report 36e, returned to Sol; beamback 2793 AD

…appear to be a bi-pedal hominid spacetravelling species, occupying the second planet of G09 – 034T…

One of the biggest faults with the concept of a one-shot slower-than-light colony mission was the proportion of the time spent accelerating and slowing down. Take Barnard’s star for example. At 5.9 light years away, with a ship capable of 0.3 lights, a plausible speed for a ramscoop… you’d be there in 19.7 years, right? Wrong. It all depends on acceleration. High-speed acceleration is expensive and creates engineering stresses, to say nothing of the stresses on the biological matter. A slow steady push is best. You accelerate slowly for at least a third of your trip. And then you have to slow down again. If you’re going to visit a number of systems, this adds HUGELY to travel time. What’s more,  the momentum you’ve lost has to be built again. Momentum is expensive. It is energy. Energy, whether taken from solar-pumped lasers or a-bombs is a consumable. Even if it is ‘free’ solar power, it still costs to get it into a usable form, and once it has been used, it is gone. A metal Space habitat has finite lifespan – but it is an enormous one. The depreciating cost, amortized over its space-life, divided by its carrying capacity, makes it the cheapest vehicle humanity ever built. However: Building the momentum needed to travel between the stars is too expensive to waste on ‘one stop’ journeys, or even on leapfroging between stars. Once the colony ship accelerates it must never slow down again. Never. It will drop space habitat modules at each sun. But it must just keeps cruising slowly along, a slow train to the stars.

From SLOWTRAIN: THE STARS WITHIN OUR GRASP, Conquist, A., Mordaunt Scientific Press, NY. 2090.

“Do you want to colonize planets? Or do you want to colonize space? The former is much less practical.”

Author unknown

They looked like a string of tiny jewels. Jewels racing across the heavens. The astronomer waited, hardly daring to breathe.
Precisely at the predicted time there was a brief flare of light.  He hastily got up from his seat behind the hi-res screen. They had to get a move on to be ready in time! It was only fifteen years away.
That was a short time by interstellar travel standards. A bit long for him though… Weight would be a problem in the interception ship. He’d be changing sex about then, with all the weight-gain that implied. Oh well, there were hormones you could use. They did shorten your life expectancy — but that wasn’t going to be a problem. The people going on this trip didn’t have much of a one. He’d have to start recruiting. The crew would need to be specialists in two fields each, and more if possible. And they would have to be at least technically insane.



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