Fastest Possible Interstellar Ship Construction and Launch

[Linguofreak]

Hmm... was that parallel to the eccliptic or at an angle?

Perpendicular.

In my scenarios, barring a truly near miss either the Sun and outer gas-giants stayed together or the inner planets stayed together a la Garyw's scenario.

Keep in mind that the closest approach to the Sun here is 0.3 AU.

 

[Hlynkacg]

Keep in mind that the closest approach to the Sun here is 0.3 AU.

Noted. Maybe I need to go back and run a few more tests.

 

[Admiral_Ritt]

2) Mars and many of the outer moons have sufficient gravity to be "close enough" and even if we reject them as candidates there is still the option of 1g O'Niel cylinders or 2001-style wheel stations as I've already proposed. Both of which are in many ways preferable to being confined to an Iceball for the unknown number of generations it would take to reach another solar system that may or may not have a habital world for us to colonise.

I don't think anything constructed in space quickly will last 3-5,000 years. too much debris out there
smashing into your ship

You will need to grow crops, not just for survival, but for the rejuvenation of
seeds. A weel would not be large enough, Oneill colonies take too long to
build

Close enough on gravity? for moons or planets, I would not take the
chance, and would try the Ice ball (that I can tunnel and put into rotation to create A-gravity)
route if I had a ticket. However
you are welcome to try reproducing at .38 G. And that goes for all
biology that you will need on your "colony"

I think a planet based effort would be doable, would there be enough time to build the infrastructure
requried to make it viable, The ice ball is a home underconstruction, I would never say it way 100%
operational in 10 years. I think the odds favor the ball, but you place your bets as best one sees it.

A black hole of sufficient mass to scatter the outer gas giants would also prevent any vessel from escaping in the process (unless you have a plan to attain relativistic velocity in the time frame alotted your iceball-turned-noah's-ark will simply be dragged into orbit around it). If the Sun and outer planets are not destroyed than why wouldn't you stay to harvest them for resources/enegy?

Not really, You must leave a high speed though and 2-3 years before black
hole arrival, and you would have to take into account into your course the
perturbation from the nearby black hole.

Obcouse if we knew that the black hole would not destroy the outer jovians, you can try and send
floating colonies there. But again time and distance is the problem. Plus hopefully you would have enough
atmosphere above and distrance to keep from getting fried by the black hole's radiation, and just what kind
of natural reasources could you extract from Neptune's atmosphere?

 

[garyw]

just what kind
of natural reasources could you extract from Neptune's atmosphere?

Hydrogen.

 

[APDAF]

You also have a large methane deposits on Titan if it does not get smashed by debris.

 

[Hlynkacg]

I don't think anything constructed in space quickly will last 3-5,000 years. too much debris out there
smashing into your ship

All the more reason to colonize the immediate stellar niehgborhood where energy and raw materials are abundent rather than interstellar space where they aren't.

Close enough on gravity? for moons or planets, I would not take the
chance, and would try the Ice ball (that I can tunnel and put into rotation to create A-gravity) route if I had a ticket. However you are welcome to try reproducing at .38 G. And that goes for all biology that you will need on your "colony"

.38 G is more than enough to sustain the basic biological functions of any fish or mammal in fact 1/6 G is more than enough. The only reason we worry about maintaining a 1 G enviroment is because eventially the Astronauts are going to return to Earth and we don't want them to be cripples when they do. Seeing as no one will be returning to Earth spending the rest of one's life in 0.38 G poses no problem.

Infact, lower gravity actually increases fertility and reduces risk of certain diseaeses because the body doesn't have to work as hard to maintain circulation and breathing.

I think a planet based effort would be doable, would there be enough time to build the infrastructure requried to make it viable, The ice ball is a home underconstruction, I would never say it way 100% operational in 10 years. I think the odds favor the ball, but you place your bets as best one sees it.

This is actually an even bigger argument against the Iceball plan than those already stated. Assuming you even make it to another star system you're still going to be starting from scratch on whatever planet you land on using only the resources available to the inhabitants of iceball, and that's assuming any of the planets there are habitable in the first place.

In contrast the construction of an O'niel cylinder or the colonization of a local body could make use of the combined resources of all of humanity. As fun as it may be to do a live-action "Space Battleshi Yamamoto" there's no need to weld ocean-going vessels to pusher plates when you can simply put every single person in every single factory on the planet to work building Boosters and Modules. Hundreds upon hundreds of launches a day, every day of every year, until the job is done or we are destroyed.

If you really want to go interstellar do a proper job of it, build a Daedalus style 2-stage plasma-jet and get yourself to Barnard's Star in 100 years vice 5,000. Like you said, time is short

Obcouse if we knew that the black hole would not destroy the outer jovians, you can try and send
floating colonies there. But again time and distance is the problem.

...and as already stated time and distance to the outer jovians is multiple orders of magnitude less than to even the closest star.

---------- Post added at 08:11 PM ---------- Previous post was at 07:56 PM ----------

You also have a large methane deposits on Titan if it does not get smashed by debris.

And you could do a pretty thorough job of terreforming Mars my slamming a few iceballs into it along with some organic compounds harvested from titan and elsewhere.

Get that atmo nice and thick.

Well thicker...

 

[APDAF]

I think we need a more realistic scenario than a black hole.

 

[Admiral_Ritt]

Well, since other rougue objects such as neutron stars, white dwarts,
we know are not closeby and heading in our direction. what else?

the only candidate is a low mass brown drwarf.
something on order of 10 jupiter masses.

yes, this much more realistic as many exists, but unlikely as we might have detected it
through infrared (the WISE project should have had a good chance of
detecting it.

But this only a real threat excintiion threat if

1) It was moving fast.

2) it was discoevered late, and we have 3-4 years of warning.

3) placed it on course toward impact to our sun or
an orbit that causes tremedous tidal heating.

If all 3 were true, then you would have enough time to k.y.a.g.

 

[APDAF]

I was thinking more of a man made event or a very large supervolcanic eruption that would make our planet uninhabitable.

 

[Linguofreak]

3) A black hole of sufficient mass to scatter the outer gas giants would also prevent any vessel from escaping in the process (unless you have a plan to attain relativistic velocity in the time frame alotted your iceball-turned-noah's-ark will simply be dragged into orbit around it).

You need to study up on your orbital mechanics. The whole solar system would already be on an escape trajectory, since the black hole is approaching from outside. Furthermore, relativistic velocities wouldn't be involved for any object that didn't approach to within 10000 km or so of the hole (assuming a 10 solar mass hole). From a gravitational standpoint, the effect on the solar system would be the same as a 10-solar mass normal star on the same trajectory.

In fact, the black hole would actually make it *easier* to escape the solar system, by making a powered flyby of the hole as it passed through.

 

[Hlynkacg]

You need to study up on your orbital mechanics. The whole solar system would already be on an escape trajectory, since the black hole is approaching from outside. Furthermore, relativistic velocities wouldn't be involved for any object that didn't approach to within 10000 km or so of the hole (assuming a 10 solar mass hole). From a gravitational standpoint, the effect on the solar system would be the same as a 10-solar mass normal star on the same trajectory.

In fact, the black hole would actually make it *easier* to escape the solar system, by making a powered flyby of the hole as it passed through.

That's because a barring an actual collision a 10 solar mass black hole on a hyperbolic trajectory probably wouldn't consume the solar system.

Therefore the black hole in question must be orders of magnitude larger and seeing as it's less than ten years away I don't see how you could build a vessel, launch it, and reach "minimum safe distance" in less than 10 years with out accelerating to a measurable percentage of the speed of light.

 

[Urwumpe]

In fact, the black hole would actually make it *easier* to escape the solar system, by making a powered flyby of the hole as it passed through.

By orbital mechanics, yes. By the X-Ray radiation around it while feeding, better not.

I think the term "rogue object" is a bit overestimated there. Space is mostly empty. When galaxies collide, there are extremely few star collisions, since the distances between the stars in each galaxy makes a collision extremely unlikely.

A brown dwarf on collision course would be still visible from some distances away. Also, you need to remember that such an object would have some velocity relative to the solar system already before it enters it.

The solar system moves at 225 km/s around the galaxy. If the brown dwarf would be standing still (unlikely), the speed of this brown dwarf when passing 1 AU distance to the sun would be:

[math]v = \sqrt{2 \cdot {29,3}^2 + 225^2 \frac{km^2}{s^2}} = 228.8 \frac{km}{s}[/math]

Or almost 8 times faster than Earth. It would travel 0.13 AU per day at that distance.

 

[Linguofreak]

That's because a barring an actual collision a 10 solar mass black hole on a hyperbolic trajectory probably wouldn't consume the solar system.

It certainly wouldn't consume the solar system (it wouldn't even consume planet if it hit it directly, given that a 10 solar mass black hole is only 30 km across, though it would reduce it to rubble), but it need not consume the solar system to destroy it. If it passed within a few AU of the Sun it would very probably scatter the entire system.

Therefore the black hole in question must be orders of magnitude larger and seeing as it's less than ten years away I don't see how you could build a vessel, launch it, and reach "minimum safe distance" in less than 10 years with out accelerating to a measurable percentage of the speed of light.

The primary hazard a solitary black hole would present to Earth is that of scattering the solar system, thus rendering Earth uninhabitable by lack of sunlight. Otherwise the minimum safe distance is extremely close on astronomical scales, and you'd be almost certain to already be outside it or be able to get outside it at a fairly leisurely velocity on ten years warning unless the hole was so extremely massive as to be detectable far more than ten years out.

 

[jedidia]

Are we talking about an african black hole or a european black hole? :lol:

 

[Linguofreak]

By orbital mechanics, yes. By the X-Ray radiation around it while feeding, better not.

I think, though, that the general assumption in this thread has been that this is a solitary black hole, which would mean it would have nothing to feed on (short of a direct collision with a solar system object). Of course, then the question is "how do we detect a solitary stellar black hole with 10 years warning?" (assuming it would be stellar because supermassive black holes seem to only show up in galactic cores).

A brown dwarf on collision course would be still visible from some distances away. Also, you need to remember that such an object would have some velocity relative to the solar system already before it enters it.

Certainly, based on typical speeds of supernova remnants I've been assuming a velocity-at-infinity of 100 km/s (which is actually probably a bit low, but within an order of magnitude) for the black hole.

---------- Post added at 02:36 ---------- Previous post was at 02:29 ----------

Are we talking about an african black hole or a european black hole? :lol:

Either. Black holes can be completely characterized by 4-momentum (which is mass, kinetic energy, and momentum rolled together into one 4 dimensional vector), angular momentum, and charge, so there's no difference between an African and a European black hole. :lol:

(Or one could say "European" and make some joke about the LHC being in Europe not Africa and the whole "the LHC will make micro-black-holes and doom us all" scare.)

 

[Urwumpe]

Are we talking about an african black hole or a european black hole? :lol:

Uh, I don't know. *Leaves Galaxy*

 

[T.Neo]

Are we talking about an african black hole or a european black hole?

Probably one from Europe, cause any black holes around here would probably be poached and have their accretion disks sold in the far east as an aphrodisiac...

 

[Admiral_Ritt]

Remember the brown dwarf and black hole would have 1 thing
in common, in this scenario.

They would have to be part of a double system. A sun that they were orbiting has gone nova. To account for their speed in approaching us.

Intersting to think about what would happen if the brown dwarf got too close, if our sun destroyed it and it's remnants began falling sunward. It would mean over time the sun would be slightly hotter due to the additional mass. It would not be much, maybe 30-50 kelvins. Would that put mars into play in terms shirtsleve habitablity, if it's orbit was not pertubed too much ?
and earth's orbit placed on a highly eliptical orbit. (6 years of frezzing, 5 months tolerable, 3 Month very hot, 1 Month (the sun is the size of a plum at arms lenght kind of hot.)

 

[Urwumpe]

Remember that the acceleration by any such objects passage on Earth will be small and only peak for a short time. It is not comparable to rocket engines. The acceleration will also not be directed in the optimal direction for an orbit change, it will be a perturbation.

What could really ruin the day would be Earth being outside the hill sphere of the sun for a longer time during the passage. But even for a 10 solar masses black hole, this would mean a pretty close passage - the hill sphere of the sun is currently at about 1.5 LY radius (actually it is an oddly shaped region, but lets keep it simple)

Just as example, if the black hole would be 10 AU away, the hill sphere of the sun would be only approximately 4.6 AU large. (1 AU = 0.46). That would mean bad news for everything beyond Earth, but everything 1.5 AU distance to the sun would still be stable.

 

[Linguofreak]

They would have to be part of a double system. A sun that they were orbiting has gone nova. To account for their speed in approaching us.

Not so for a black hole. Newborn neutron stars have been known to acquire fairly high velocities (in the 100's of km/s) from asymmetries in the supernovae that produce them, and it's almost certain that the same thing happens with black holes as well (though it's hard to verify because a solitary black hole is hard to detect).