Generation Ships--- Can we build one now?

MarkB · Jan 27, 2019

Nutation said:
I wouldn't try it before the various technologies have stabilized (stopped improving). Otherwise, ship #2 passes ship #1 and arrives first.
Actually, that's also a way to send new supplies and parts, so maybe it's not a show-stopper.

Generation ships aren't a great option unless you're desperate, for a lot of the reasons mentioned in this thread. Ideally, you want to wait until you've perfected something along the lines of cryogenics/stasis/time-dilation, so that you don't need to deal with the logistics of keeping humans alive and conscious for hundreds of years in space.

Tonguez · Jan 27, 2019

Nutation said:
I wouldn't try it before the various technologies have stabilized (stopped improving). Otherwise, ship #2 passes ship #1 and arrives first.
Actually, that's also a way to send new supplies and parts, so maybe it's not a show-stopper.

That would be an interesting premise for a short story - the first great generation ship is launched and 1000 years later arrives on a new planet only to discover that they are late, later colonist arrived 300 years prior and their entire culture of believing they were humanities last hope is now obsolete

Hussar · Jan 28, 2019

Tonguez said:
That would be an interesting premise for a short story - the first great generation ship is launched and 1000 years later arrives on a new planet only to discover that they are late, later colonist arrived 300 years prior and their entire culture of believing they were humanities last hope is now obsolete

It has been done. Robert Reed and Stephen Baxter both have short stories along these lines. Alastair Reynolds too IIRC. But, I'm sorry, I can't for the life of me remember the titles.

Shasarak · Jan 28, 2019

Tonguez said:
That would be an interesting premise for a short story - the first great generation ship is launched and 1000 years later arrives on a new planet only to discover that they are late, later colonist arrived 300 years prior and their entire culture of believing they were humanities last hope is now obsolete

I think I remember a Star Trek next Generation story where the Enterprise intercepts an old colony ship.

Eltab · Jan 28, 2019

NASA sent up a married couple on one of the last Shuttle flights, and made a point of allocating them some time to be alone together with no other pressing duties.

Reports on the results of this experiment were of course not made public. Personally, I would not be surprised to find out "Oops, we relaxed and fell asleep" because it was the only break in their busy pre-programmed week long schedule.

As for generation ships … we have to figure out, build, and operate a closed ecosystem (in a stays-put station or asteroid or something) first. The theory looks good, but the practice has a long way to catch up. Maybe my grandchildren will see the ship's keel-laying ceremony.

Zardnaar · Jan 28, 2019

Hussar said:
It has been done. Robert Reed and Stephen Baxter both have short stories along these lines. Alastair Reynolds too IIRC. But, I'm sorry, I can't for the life of me remember the titles.

Harry Turtledove as well. They invented ftl after a sublight ship was sent out.

Olgar Shiverstone · Jan 28, 2019

Hussar said:
It has been done. Robert Reed and Stephen Baxter both have short stories along these lines. Alastair Reynolds too IIRC. But, I'm sorry, I can't for the life of me remember the titles.

I think Larry Niven did this as well. Many of his original Known Space worlds were colonized with generation or sleeper ships, but I vaguely remember one where they took so long that an FTL ship eventually caught up (and his Protector aliens never developed FTL).

Ryujin · Jan 28, 2019

I think that a generation ship would be possible, given current technology. It would, however, require a massive planet-wide effort to accomplish. We have reasonably good prototyping tech that could be adapted to produce replacement parts for many items. A large enough, segmented biosphere would permit failure of some, with recovery possible from others. Rotational 'gravity' would help to avoid muscle and bone atrophy. Nuclear power for drive, with slow and constant radial acceleration, should be possible at current tech, assuming something more efficient doesn't turn up soon. (Seems the EM drive is a non starter.)

If you wait for the next big jump in tech then nothing ever gets done.

lowkey13 · Jan 28, 2019

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BornChaoticNeutral · Jan 28, 2019

Zardnaar said:
No main reason is we don't have a planet we can go to followed by we don't know what the effects of long term exposure to zero/low g would be. IDK if we have artificial gravity.

It also takes 12 years to get to the edge of the solar system. We would need some sort of nuclear/fusion power, some sort of artifical gravity and a planet that is confirmed that can support human life. Then we would also have to deal with alien microbes if we got there.

Isn't the whole point of a generation ship to just go out and explore but not necessarily having a destination?