Alpha Centauri B may have "superhabitable" worlds

JadeStar

crazyewok

Blue Shift
I'll bet a dollar that we don't make it out of our own Solar System before we either give it all up to the androids or modify ourselves genetically to such an extent that we can no longer consider ourselves human. That gives us about 1,000 years, tops.

You do know nuclear pulse propulsion (which most physicists agree would work) could get us there in 100 years? And that was 60 years ago. Fusion pulse which is a very real possibility could get us there in half that time?

Fusion pulse still suffers from the relativistic mass problem. The faster a ship goes approaching the speed of light, the more massive it becomes, which means its harder to accelerate.

So the best ideas lately have been to use beamed propulsion so that the fuel is all back at the solar system. No fuel on the ship hardly means less rest mass to accelerate.

unfortunately for beamed propulsion the cost is typically calculated as a megawatt per kilogram so it's kind of impractical. (besides here i also hang out at NASA's advanced Concept forums so am generally familiar with all the problems associated with various propulsion proposals.)

And we don't need light speed to get to the nearest stars. there is a point up to which you can tolerate the inertial mass trade off and a trip time at which it is acceptable to send humans expecting to return home, and one for those who don't care if they return home.

stormbringer1701

JadeStar

crazyewok

Blue Shift
I'll bet a dollar that we don't make it out of our own Solar System before we either give it all up to the androids or modify ourselves genetically to such an extent that we can no longer consider ourselves human. That gives us about 1,000 years, tops.

You do know nuclear pulse propulsion (which most physicists agree would work) could get us there in 100 years? And that was 60 years ago. Fusion pulse which is a very real possibility could get us there in half that time?

Fusion pulse still suffers from the relativistic mass problem. The faster a ship goes approaching the speed of light, the more massive it becomes, which means its harder to accelerate.

So the best ideas lately have been to use beamed propulsion so that the fuel is all back at the solar system. No fuel on the ship hardly means less rest mass to accelerate.

unfortunately for beamed propulsion the cost is typically calculated as a megawatt per kilogram so it's kind of impractical. (besides here i also hang out at NASA's advanced Concept forums so am generally familiar with all the problems associated with various propulsion proposals.)

And we don't need light speed to get to the nearest stars. there is a point up to which you can tolerate the inertial mass trade off and a trip time at which it is acceptable to send humans expecting to return home, and one for those who don't care if they return home.

All true.

I was thinking more or less in terms of a quick probe to Alpha Centauri. And while we don't need 0.90c travel to the nearest stars for probes or people even, it would be very nice to be able to send out a bunch of quick probes at these speeds to the nearest systems for in situ planet characterization and cartography before sending something with a human crew much slower.

Of course for the cost of building such infrastructure we probably could build several full scale terrestrial planet mapper interferometers.

I'm glad you post on ATS by the way

JadeStar

stormbringer1701

JadeStar

crazyewok

Blue Shift
I'll bet a dollar that we don't make it out of our own Solar System before we either give it all up to the androids or modify ourselves genetically to such an extent that we can no longer consider ourselves human. That gives us about 1,000 years, tops.

You do know nuclear pulse propulsion (which most physicists agree would work) could get us there in 100 years? And that was 60 years ago. Fusion pulse which is a very real possibility could get us there in half that time?

Fusion pulse still suffers from the relativistic mass problem. The faster a ship goes approaching the speed of light, the more massive it becomes, which means its harder to accelerate.

So the best ideas lately have been to use beamed propulsion so that the fuel is all back at the solar system. No fuel on the ship hardly means less rest mass to accelerate.

unfortunately for beamed propulsion the cost is typically calculated as a megawatt per kilogram so it's kind of impractical. (besides here i also hang out at NASA's advanced Concept forums so am generally familiar with all the problems associated with various propulsion proposals.)

And we don't need light speed to get to the nearest stars. there is a point up to which you can tolerate the inertial mass trade off and a trip time at which it is acceptable to send humans expecting to return home, and one for those who don't care if they return home.

All true.

I was thinking more or less in terms of a quick probe to Alpha Centauri. And while we don't need 0.90c travel to the nearest stars for probes or people even, it would be very nice to be able to send out a bunch of quick probes at these speeds to the nearest systems for in situ planet characterization and cartography before sending something with a human crew much slower.

Of course for the cost of building such infrastructure we probably could build several full scale terrestrial planet mapper interferometers.

I'm glad you post on ATS by the way

edit on 30-1-2014 by JadeStar because: (no reason given)

Obviously probes are expensive, but why havent there been more sent on interstellar missions? Of course voyager is debatably just exiting the solar system now after 40 something years, but are there actual plans to get moving on sending probes to check out the nearest star systems?

And also is there something to the idea (in regards to doing a little to help the time factor) to sending a probe in the direction of "behind our stars direction of travel"? Meaning if the sun is traveling in a revolution galactically, then if we were to send a probe in the opposite direction of travel, we can assume the stars behind would (obviously not exactly because such different velocities involved) 'meet the probe halfway'? Like the difference between throwing a tennis ball out of a moving car to the car ahead of you as opposed to the car driving behind you, ever towards you.

crazyewok

Blue Shift
I'll bet a dollar that we don't make it out of our own Solar System before we either give it all up to the androids or modify ourselves genetically to such an extent that we can no longer consider ourselves human. That gives us about 1,000 years, tops.

You do know nuclear pulse propulsion (which most physicists agree would work) could get us there in 100 years? And that was 60 years ago. Fusion pulse which is a very real possibility could get us there in half that time?

In Star Trek, they have advanced shields. Also, Impulse Drives don't travel anywhere near the speed of light, making maneuvering around things much easier, and the things that do hit you don't do as much damage. That was my whole point. They don't use the impulse drives to travel to another star system either.

There is one thing we could do Right now to get the ball rolling: Get Dr Wing Lee's M2P2 coffee can sized sail generator and use it combined with gravity assists to get a probe up to nearly 157,000MPH (or more) then with it starting at the sun unfurl the plasma sail to 20 KM radius and accelerate to the speed of the stellar wind on top of that. it's still slow as relativistic speeds go but incredibly fast compared to anything we have now. and it can do science from the very start. such as verify impact hazard occurrence rates, planetary science, navigation details, see exactly how far out our electronic signals from earth leak out before being undetectable, look for watering holes in the Oort cloud, look for hidden rogue worlds and cool brown dwarfs, point a webb class or newer scope at the targets, monitor the target for technological signatures, just lots of stuff even if the trip takes nearly a thousand years the science returns begin immediately.

of course the way telescope technology is going soon we will be able to read books over any aliens shoulders with earth bound telescopes anyway. we are already looking at cloud cover on alien worlds and brown dwarfs. with a disk resolved better than high priced amateur telescopes can resolve mars.

but we need the m2p2 anyway for radiation shielding and potentially dust and grain shielding.

JohnnySasaki

crazyewok

Blue Shift
I'll bet a dollar that we don't make it out of our own Solar System before we either give it all up to the androids or modify ourselves genetically to such an extent that we can no longer consider ourselves human. That gives us about 1,000 years, tops.

You do know nuclear pulse propulsion (which most physicists agree would work) could get us there in 100 years? And that was 60 years ago. Fusion pulse which is a very real possibility could get us there in half that time?

In Star Trek, they have advanced shields. Also, Impulse Drives don't travel anywhere near the speed of light, making maneuvering around things much easier, and the things that do hit you don't do as much damage. That was my whole point. They don't use the impulse drives to travel to another star system either.

TOS impulse was artificially limited to .25 c because of time dialation effects messing with thier comms , nav and computer clocks. they could actually pull.5 c and by voyager's time they could do nearly.8 c.

the impulse system was not a rocket even though it was a fusion engine. the KE was derived from a quantum coupling effect which overcame some efficiency limits the writers presumed existed with a direct rocket drive. the impulse system also had a thrust reverse system. i suspect that initially the writers were using them as a standard rocket type engine because the louvres were probably thrust reversers like used in current jet engines. there is a lot of ret-conning throughout the life of the franchise.

of course when you get to the heliopause you would drop the sail and keep it dropped unless you discovered some sort of worthwhile interstellar wind going in your direction or a wind that was tack-able to. there is also a beamed power varient:

from the wiki:

Robert Winglee, who originally proposed the M2P2 technique, calculates a specific impulse of 200 kN·s/kg (roughly 50 times better than the space shuttle main engine). These calculations suggest that the system requires on the order of a kilowatt of power per newton of thrust, considerably lower than electric thrusters, and that the system generates the same thrust anywhere within the heliopause because the sail spreads automatically as the solar wind becomes less dense. However, this technique is less well understood than the simpler magnetic sail and issues of how large and heavy the magnetic coil would have to be[3][5] or whether the momentum from the solar wind can be efficiently transferred to the spacecraft[6] are under dispute.
The expansion of the magnetic field using plasma injected has been successfully tested in a large vacuum chamber on Earth, but the development of thrust was not part of the experiment. A beam-powered variant, MagBeam,[7] is also under development.

ImaFungi



Obviously probes are expensive, but why havent there been more sent on interstellar missions? Of course voyager is debatably just exiting the solar system now after 40 something years, but are there actual plans to get moving on sending probes to check out the nearest star systems?

And also is there something to the idea (in regards to doing a little to help the time factor) to sending a probe in the direction of "behind our stars direction of travel"? Meaning if the sun is traveling in a revolution galactically, then if we were to send a probe in the opposite direction of travel, we can assume the stars behind would (obviously not exactly because such different velocities involved) 'meet the probe halfway'? Like the difference between throwing a tennis ball out of a moving car to the car ahead of you as opposed to the car driving behind you, ever towards you.

periodically there are official studies for interstellar probes. and some private clubs do such studies as well. most recently was the 100 year starship meetings. there are also some emerging private crowd funding efforts.

the issues with interstellar travel even for probes are daunting. chemical power just can't do it and basically you can't put a reactor in space or little atomic bomblets either. so you are hobbled from the start. not only that but issues of shielding, position finding, navigation, autonomous decision making, the rocket equation means you have to either go very very very big or go very very small (with no way to really pull it off technologically) you need at least a 3 and preferably bigger megawatt transmitter and a remote relay system that costs money and has a lot of overhead on it's own. then when you get there how do you stop? if you don't stop how much scince can you do flying by the fastest you could go? the time to payoff means pensions and salaries, and people obligated to be standing by...

you next question is easier...

ccording to NASA, the Solar System is traveling at an average speed of 828,000 km/h (230 km/s) or 514,000 mph (143 mi/s) relative to the galactic center,[3] which is about one 1300th of the speed of light. If you could travel at that speed in a jet aircraft along the equator, you would go all the way around the world in approximately 2 minutes and 54 seconds. According to NASA, even at this incredible speed, it still takes the solar system 230 million years to orbit the center of the Milky Way Galaxy one time.[3]

if there is a star aft of our sun within a reasonable distance that i would guess you could add that speed to any propulsion you plan to use. you also have to consider the star's own motion; eg; proxima is booking it away from alpha centauri while some stars are getting closer. barnard's star is getting closer i think. but with what we have available in terms of near term propulsion solutions you are still talking decades for a trip of 4 lightyears. so you have to pick tagets wisely. fortunately the centauri system is a three for the price of one proposition and is the closest, and has two sun like stars and a bonus red dwarf.

here is a map that gives the relative positions of stars around sol:

www.solstation.com...

looking at that map you could do alpha proxima, alpha Kentarus, Alpna kentarus b (toliman's star?), and then send probes on from there to Sirius and Luyten 726-8 AB. there is a nice curve path between sol and all of those places.

Kentaris being one of several old names for Alpha Centauri. it has been known as kentarus, tolliman, rigel kentarus, oh the heck with it... here's from the wiki:

The colloquial name of Alpha Centauri is Rigel Kent or Rigil Kent,[112] short for Rigil/Rigel Kentaurus,[113][nb 1] the romanization of the Arabic name رجل القنطورس Rijl Qanṭūris,[112] from the phrase Rijl al-Qanṭūris "the foot of the Centaur".[114] This is sometimes further abbreviated to Rigel, though that is ambiguous with Beta Orionis. Although the short form Rigel Kent is common in English, the stars are most often referred to by their Bayer designation Alpha Centauri.
A medieval name is Toliman, whose etymology may be Arabic الظلمان al-Ẓulmān "the ostriches".[112] During the 19th century, the northern amateur popularist Elijah H. Burritt used the now-obscure name Bungula,[115] possibly coined from "β" and the Latin ungula ("hoof").[112] Together, Alpha and Beta Centauri form the "Southern Pointers" or "The Pointers", as they point towards the Southern Cross, the asterism of the constellation of Crux.[35]
In Chinese, 南門 Nán Mén, meaning Southern Gate, refers to an asterism consisting of α Centauri and ε Centauri. Consequently, α Centauri itself is known as 南門二 Nán Mén Èr, the Second Star of the Southern Gate.[116]
To the Australian aboriginal Boorong people[who?] of northwestern Victoria, Alpha and Beta Centauri are Bermbermgle,[117] two brothers noted for their courage and destructiveness, who speared and killed Tchingal "The Emu" (the Coalsack Nebula).[118] The form in Wotjobaluk is Bram-bram-bult.[117]

reply to post by stormbringer1701


Oh I just thought if we did voyager 40 years ago, considering how much our understanding and application in the fields of computation and robotics and material sciences and things like solar power and solar sails, perhaps it would be interesting to begin working on the latest cutting edge probe to begin the trek to the nearest star system to give our future a head start. Does the mars rover take up most of NASAs budget, well that and the space station I suppose.

ImaFungi
reply to post by stormbringer1701

 

Oh I just thought if we did voyager 40 years ago, considering how much our understanding and application in the fields of computation and robotics and material sciences and things like solar power and solar sails, perhaps it would be interesting to begin working on the latest cutting edge probe to begin the trek to the nearest star system to give our future a head start. Does the mars rover take up most of NASAs budget, well that and the space station I suppose.

hey, i"m definitely not discouraging or debunking the idea. i want to see it happen. and we are really on the very verge of being able to do it despite what some critics say. but i just want enthusiasts to know its a monumental task. that's no reason to put it off though. propulsion is getting there. the rest of the tech is improving rapidly. on that note; look at picture series from an earth bound telescope:

www.sciencedaily.com...

we have now imaged the weather on a super earth and a brown dwarf. we can detect clouds, continents or ice caps now. if the circumstances are right we can get a read out of atmospheric composition spectra of exo-planets. the next generations of instruments will be able to do far more with far smaller targets. especially on closer stars and planets. the super earth they imaged weather on was a long, long, long, long, long way away compared to Alpha proxima, alpha centauri and AC-B.

Voyager proves we can both tolerate and run a multi-decades long space mission. it proves a probe can keep from getting banged out of commission or wearing out instruments even over decades. if we did send a probe chances are it would be with 100 year to target propulsion or less if it's destination is alpha centauri. we need to get with it and produce that propulsion system.

JadeStar

Fusion pulse still suffers from the relativistic mass problem. The faster a ship goes approaching the speed of light, the more massive it becomes, which means its harder to accelerate. Fuel ads mass to this problem.

I thought 30% was possible?

I know Daedalus was 12%c and had a 50 year mission time.

JohnnySasaki

crazyewok

Blue Shift
I'll bet a dollar that we don't make it out of our own Solar System before we either give it all up to the androids or modify ourselves genetically to such an extent that we can no longer consider ourselves human. That gives us about 1,000 years, tops.

You do know nuclear pulse propulsion (which most physicists agree would work) could get us there in 100 years? And that was 60 years ago. Fusion pulse which is a very real possibility could get us there in half that time?

In Star Trek, they have advanced shields. Also, Impulse Drives don't travel anywhere near the speed of light, making maneuvering around things much easier, and the things that do hit you don't do as much damage. That was my whole point. They don't use the impulse drives to travel to another star system either.

We don't live in the world of starter so whats your point? We are stuck with sub lightspeed velocitys.

crazyewok

JohnnySasaki

crazyewok

Blue Shift
I'll bet a dollar that we don't make it out of our own Solar System before we either give it all up to the androids or modify ourselves genetically to such an extent that we can no longer consider ourselves human. That gives us about 1,000 years, tops.

You do know nuclear pulse propulsion (which most physicists agree would work) could get us there in 100 years? And that was 60 years ago. Fusion pulse which is a very real possibility could get us there in half that time?

In Star Trek, they have advanced shields. Also, Impulse Drives don't travel anywhere near the speed of light, making maneuvering around things much easier, and the things that do hit you don't do as much damage. That was my whole point. They don't use the impulse drives to travel to another star system either.

We don't live in the world of starter so whats your point? We are stuck with sub lightspeed velocitys.

I assume you meant "Star Trek"? We're stuck with sub light speed velocities now, but if you read my previous posts, you'll see I make a fairly solid case for that ending within the next couple of decades. Technological advancement seems to be exponential, not linear.

crazyewok

JadeStar

Fusion pulse still suffers from the relativistic mass problem. The faster a ship goes approaching the speed of light, the more massive it becomes, which means its harder to accelerate. Fuel ads mass to this problem.

I thought 30% was possible?

I know Daedalus was 12%c and had a 50 year mission time.

inertial mass gain is not truly prohibitive until about 70 to 75 percent c. even that is arguable.

crazyewok


We are stuck with sub lightspeed velocitys.

i don't think so. but i don't know when we will find way to fulfill the special conditions that do allow it in relativity.

reply to post by Mamatus


There are probably a thousand reasons why humanity may never colonize another world. Alien microorganisms being only one reason. We're talking about someplace where people would have to live... Not just work and move around in exo-suits. I wonder if we could adapt? I wonder if we will make it that far as a species.

Chronogoblin
reply to post by Mamatus

 

There are probably a thousand reasons why humanity may never colonize another world. Alien microorganisms being only one reason. We're talking about someplace where people would have to live... Not just work and move around in exo-suits. I wonder if we could adapt? I wonder if we will make it that far as a species.

maybe. maybe not. you know that microorganisms that can infect humans generally evolved that way or at least evolved the ability to affect related species. Odds are micro-organisms from another planet are adapted to infect species from that planet they co-evolved with. they develop toxins for example that work on a certain type of metabolic pathway or organic function often it only works on a certain species or set of species. there are a few by accident that affect humans strongly. like box jellyfish toxin or sydney funnel web spiders or widow family spiders. these are all multi-cellular animals though. if we do get an Exo bug that can affect humans it will probably be an accident of nature. but we had that happen before.the colonists had a period of illness when they first came to america as all the microbes were unfamiliar to their immune system. but they were still close enough in evolution to be able to make the jump. and they (at least some of them) survived that immunological assault. the ones that died died of starvation, exposure, and known infectious diseases they already had exposure to anyway like cholera and so forth.

stormbringer1701

Chronogoblin
reply to post by Mamatus

 

There are probably a thousand reasons why humanity may never colonize another world. Alien microorganisms being only one reason. We're talking about someplace where people would have to live... Not just work and move around in exo-suits. I wonder if we could adapt? I wonder if we will make it that far as a species.

maybe. maybe not. you know that microorganisms that can infect humans generally evolved that way or at least evolved the ability to affect related species. Odds are micro-organisms from another planet are adapted to infect species from that planet they co-evolved with. they develop toxins for example that work on a certain type of metabolic pathway or organic function often it only works on a certain species or set of species. there are a few by accident that affect humans strongly. like box jellyfish toxin or sydney funnel web spiders or widow family spiders. these are all multi-cellular animals though. if we do get an Exo bug that can affect humans it will probably be an accident of nature. but we had that happen before.the colonists had a period of illness when they first came to america as all the microbes were unfamiliar to their immune system. but they were still close enough in evolution to be able to make the jump. and they (at least some of them) survived that immunological assault. the ones that died died of starvation, exposure, and known infectious diseases they already had exposure to anyway like cholera and so forth.

edit on 30-1-2014 by stormbringer1701 because: (no reason given)

That, and also by the time we have ships capable of interstellar travel, we'll almost certainly have some advance form of health care in place to strengthen our immune system. Something like little nanobots in your bloodstream warding off any invaders. Even if it was a problem at first, we'd probably have a solution soon after.

If you know the whole story, we'd probably send a probe first and find out exactly what could be dangerous and find a cure before we even left earth.

i have a feeling we may be impulsive enough that the first time we find a planet with near earth gravity, temperatures, water and an oxygen nitrogen mix we'll head off as fast as we figure out how to do it I know i would.

but yeah we'll have advanced medicine to the point of custom tailoring a drug, or DNA or peptides or even nanobots. we are on the verge of doing that for cancers now. it will filter from the super-star research hospitals down to the regional and municipal hospitals rapidly too.

our biggest problem to overcome is propulsion. the rest of it is not so hard.