OT: Space Station Fun

If one builds a craft for Earth based launch, all that mass has to be pushed to escape velocity, and a good deal of the craft and its fuel volume allocation would be used on that effort.

The craft I speak of would be built in space, and ALL of its fuel volume allocation would be MISSION fuel. The craft shape would not have to consider atmospheric allowances either.

You don't get it. It does NOT matter what got spent getting it up to the platform. That is the whole point. What matters is that the mission craft you build UP THERE does not need to have all those considerations made for it, and ALL payload and fuel is for the mission, not the push off our rock.

So, sure fuel gets spent getting the elements to the platform, but the craft design does not have to have all that in it. THAT is where the savings is, and that craft is what benefits from a space based assembly and launch. All fuel allocated space get used for mission use, and none is needed for the terrestrial escape push.

When I say "savings" I do not mean that it costs us less fuel to do it. I mean that the mission craft does not have to have those elements as part of its design.

Yep. It does not need to be a huge dart shaped aero design.

PUSH the pieces up into space. The fuel expended on this portion of the mission matters not, and is what gets "saved".

ASSEMBLE the pieces into the mission craft IN SPACE.

It is quite simple and absolutely saves main mission fuel. The terrestrial escape excursion gets done with several lifting body craft meant for that job. Easy greasy.

Trying to make the mission start from Earth is stupid, because the craft itself has to be compromised from ideal, just to deal with our atmosphere and gravitational issues.

From space, an assembled craft would be built specifically for space transits, not planetary escape events.

And have yet to this day for it to go any further.

I say we were concocted.

And if DecadentLinuxUserNumeroUno ever finds out who concocted him, he'll sue - and win.

In reality, if we were concocted, we would have been better-concocted.

atomic

For one thing, it makes the timing a lot more difficult. The stellar physics makes it pretty much impossible for a star to have been born, a few billion years to pass for a civilisation to evolve, then another few billion years to spread DNA seeds to nearby galaxies (it takes quite a while to travel between galaxies) - all in time for the seeds to hit a tiny window of time between the earth being cool enough to support life, and the first known life on earth.

There is plenty of grounds for thinking that the early earth got a headstart in the formation of life through useful organic chemicals from comets and other space debris, or bigger molecules or even early lifeforms from Mars (which was a nice place for life for a short while in the early solar system). But direct seeding from another civilisation requires too much luck, or too much effort, to be believable.

Actually, research into abiogenesis has come a great deal further forward. Much of the work is on other aspects of early life (such as the formation of membranes, and of RNA) - we already know there were at least some amino acids around.

von Neumanns conjecture that if there was a significantly more advanced civilisation in the galaxy self replicating probes would be everywhere.

Sagan's counter argument is that any civilisation clever enough to manufacture vN probes would also see the intrinsic danger of them evolving through bad copies into something that destroyed planets that were already alive simply to make more copies of themselves.

The other snag here is that space is BIG *REALLY* **REALLY** ***BIG***

And such probes might arrive very infrequently and on a geologically active planet like Earth get subducted or buried by sedimentary rocks. Disappointing that there was nothing on the Moon or Mars.

It would be a very big surprise if that bright spot on Ceres did turn out to be an ancient alien space probe and its rover for instance.

There might be a slight advantage to having the ISS take a look at it to inspect for any launch damage that might affect the mission. That procedure was added to Shuttle flights after the sad re-entry failure.

But I suspect the cost of matching orbits would far outweigh any possible gains unless mission critical damage was suspected.

He is not expressing it very well, but the main thing is that you can construct a complex lighter weight even fragile structure that does not have to survive either the Earths 1g gravity or the rigors and powerful vibrations of a 6g ground based rocket launch. You take up a flat pack kit to assemble in orbit (or to have your robotic systems assemble).

It can then have an ion engine attached and be launched from orbit.

You can build a lighter weaker structure in a weightless environment and still have sufficient rigidity to be useful. Low weight will be incredibly important to use ion engines with their puny thrust.

On a sunny day (Thu, 26 Feb 2015 18:07:48 -0800 (PST)) it happened Phil Hobbs wrote in :

Why dont you go there yerselves? You seem to be unable to skip a thread, so maybe you can learn it there. We dont need no freaking mooderator PhD shit. :-)

Na, hollywood. plenty stars there.

Not fiction. He wrote many books on science as well as fiction. Consider that he wrote about the Bible and Shakespeare for just two examples. You haven't looked at his list of science books it seems. Sort of what I expected from your level of intelligence.

Like any sort of self-replicating entity, a vN probe needs to find enough resources within its lifetime to make some copies of itself for a population to persist, let alone grow. Space is pretty much empty.

We have no idea what a vN probe might look like, but here is an idea: Imagine some phenomenon that harvests clouds of hydrogen into compact hot balls that synthesize heavier elements. Rig the thing to explode after some time, scattering these elements around, reforming into little balls. On these, the elements combine to form more complex combinations, which ...

I suppose you get my drift. Stars *do* abound where resources to make them exist. :^)

Jeroen Belleman

Only the really massive stars go supernova. Ours will end its days as a planetary nebula following its red giant phase of solar wind mass loss.

OTOH Making planets might be a sport for self replicating vN probes ;-) (a theme that has appeared in new series Dr Who)

Martin Rees's book "Just Six Numbers" is an interesting read if you want to see what is left for the God of the gaps. Change any of the fundamental constants of nature and you get nothing interesting.

We are in a universe that is finely tuned for high complexity but that should not be a surprise since we are complex. Barrow's Anthropic Cosmological Principle dealt with the same topic but is a bit dated now.

Multiverse theories hold that the universe explores the whole parameter space and we happen to be in a bit that has goldilocks properties. If it were any different we would not be here to look at it.