If we find a habitable extrasolar planet, what would we do?

[grokme]

i really dont care how they do it i just want to be on that ship. i know i wont make it but maybe my great great grandkids will. generation ships are the only way that we will ever get out of this solar system

Okay, we keep talking about generation ships, but if we are able to approach the speed of light, then time dilation would occur. If the star is within the range of a human lifetime in light years, then wouldn't we be able to travel there in a lifetime if we can approach the speed of light.

 

[grokme]

Can't we harvest an asteroid, which is already moving at a pretty good clip and then direct it out of the solar system?

 

[Shpaget]

if we can approach the speed of light.

We can't achieve speeds comparable to c.
The fastest man made object is Helios 2 probe which reaches 0,0002 c in its elliptical orbit.

"Harvesting an asteroid" would require matching its speed first, so no gains there, but than you have to invest humongous amounts of energy to direct it anywhere.

 

[crazyeddie]

Okay, we keep talking about generation ships, but if we are able to approach the speed of light, then time dilation would occur. If the star is within the range of a human lifetime in light years, then wouldn't we be able to travel there in a lifetime if we can approach the speed of light.

Accelerating one ton to one tenth of the speed of light requires at least 125 billion kWh, not accounting for losses.

There is some belief that the magnitude of this energy may make interstellar travel impossible. It is reported that at the 2008 Joint Propulsion Conference, where future space propulsion challenges were discussed and debated, a conclusion was reached that it is highly improbable that humans will ever explore beyond the Solar System. Brice N. Cassenti, an associate professor with the Department of Engineering and Science at Rensselaer Polytechnic Institute, stated “At least 100 times the total energy output of the entire world would be required for the voyage (to Alpha Centauri)”

http://en.wikipedia.org/wiki/Interstell ... lar_travel

So if getting to only 1/10 of the speed of light requires that much energy, imagine how much more would be required to accelerate a ship to relativistic velocities. And then you have the problem of radiation and the abrasion caused by a ship plowing through the interstellar medium. Above .3c, interstellar gas becomes a flow of relativistic nucleons, which is nothing less than hard radiation bombarding the ship and everything aboard. Impacts with micrometeoroids would produce the equivalent energy of an atom bomb. Shielding the ship from these hazards only increases the mass and energy requirements, which are already enormous. Do you see how the problems mount up, the faster you aspire to travel?

 

[Boris_Badenov]

It doesn't use a Fusion Reactor, it's an Orion type engine.

From your Wiki article:
"This velocity is well beyond the capabilities of chemical rockets, or even the type of nuclear pulse propulsion studied during Project Orion. Instead, Daedalus would be propelled by a fusion rocket..."


Daedalus is not an Orion type engine. It is a nuclear fusion engine.

Daedalus would be propelled by a fusion rocket using pellets of deuterium/helium-3 mix that would be ignited in the reaction chamber by inertial confinement using electron beams. 250 pellets would be detonated per second, and the resulting plasma would be directed by a magnetic nozzle

A concept similar to Orion was designed by the British Interplanetary Society (B.I.S.) in the years 1973-1974. Project Daedalus was to be a robotic interstellar probe to Barnard's Star that would travel at 12% of the speed of light (0.12c). Project Orion (nuclear propulsion) Later developments

Daedalus was to be propelled by hundreds of fusion explosians per second inside a magnetically confined chamber. Orion was to be propelled by 1000 or so fusion explosions outside the ship over the course of the trip.

 

[MeteorWayne]

This discussion has veered off into a discussion about interstallar travel technology, rather than the subject of the original topic. My inclination now is to split the technology discussion into a separate thread in SB&T about methodology for interstellar travel. If anyone has any comments before I do that, post them soon.

Meteor Wayne

 

[ZenGalacticore]

So we would just sit around and remote sense it for a few centuries trying to find a way to get there? What about the idea of making hops to it? We might try our closest star within the next century or two. From there we set up an existence, maybe a remote outpost where we can build the technology for the next trip. Then over another century hop to the next one . Over time we might accumulate enough distance that we would eventually get there as a natural progression of events, not necessarily a straight trip to it.

I didn't mean to imply that we will NEVER get there, especially to star systems within a 30 light-year radius. Just not in our life times, or even our great-grandchildren's life times. But even if/when we'll be able to hop 5 or 6 lys at a time, eventually establishing outposts 30 or more lys out, it's only those that go that will get to experience it.

Of course, all the places they go will be beamed back to Earth in visual transmissions, if need be relayed from systems each on average 5 lys apart, in order to eventually receive clear transmissions back home on Earth. But we'd always have to wait on the painfully slow speed of light!

 

[grokme]

Okay, we keep talking about generation ships, but if we are able to approach the speed of light, then time dilation would occur. If the star is within the range of a human lifetime in light years, then wouldn't we be able to travel there in a lifetime if we can approach the speed of light.

Accelerating one ton to one tenth of the speed of light requires at least 125 billion kWh, not accounting for losses.

There is some belief that the magnitude of this energy may make interstellar travel impossible. It is reported that at the 2008 Joint Propulsion Conference, where future space propulsion challenges were discussed and debated, a conclusion was reached that it is highly improbable that humans will ever explore beyond the Solar System. Brice N. Cassenti, an associate professor with the Department of Engineering and Science at Rensselaer Polytechnic Institute, stated “At least 100 times the total energy output of the entire world would be required for the voyage (to Alpha Centauri)”

http://en.wikipedia.org/wiki/Interstell ... lar_travel

So if getting to only 1/10 of the speed of light requires that much energy, imagine how much more would be required to accelerate a ship to relativistic velocities. And then you have the problem of radiation and the abrasion caused by a ship plowing through the interstellar medium. Above .3c, interstellar gas becomes a flow of relativistic nucleons, which is nothing less than hard radiation bombarding the ship and everything aboard. Impacts with micrometeoroids would produce the equivalent energy of an atom bomb. Shielding the ship from these hazards only increases the mass and energy requirements, which are already enormous. Do you see how the problems mount up, the faster you aspire to travel?

Well, yes, I see that these are all technical problems that we haven't conquered. I just believe that we have the ability to overcome pretty much any technical problem we encounter. Do I know of a technology that could do that today? No, but I guess it's a religious belief that we would find a way. I'm willing to accept it isn't logical.

 

[grokme]

if we can approach the speed of light.

We can't achieve speeds comparable to c.
The fastest man made object is Helios 2 probe which reaches 0,0002 c in its elliptical orbit.

"Harvesting an asteroid" would require matching its speed first, so no gains there, but than you have to invest humongous amounts of energy to direct it anywhere.

You can't rendezvous with an asteriod? How did we land on Eros for the NEAR mission? You would have to expend huge amounts of energy to make incremental changes in an asterioid's path over long distances? I thought we could nudge an asteroid and change its path without a great amount of energy, as long as it is over great distances, as would be travel out of the solar system.

 

[grokme]

This discussion has veered off into a discussion about interstallar travel technology, rather than the subject of the original topic. My inclination now is to split the technology discussion into a separate thread in SB&T about methodology for interstellar travel. If anyone has any comments before I do that, post them soon.

Meteor Wayne

Apparently, we can't do anything with this planet but study it from afar unless it involves impossible interstellar travel within our lifetimes. Maybe we could travel piecemeal out of the solar system towards another star without having to do it in one voyage and without having to go the speed of light. It would probably involve creating deep space stations and doing it over tens of thousands of years. I was hoping to explore all possibilities for our approach after finding the habitable planet. I thought it might go in stages and someone might outline what those are.

 

[grokme]

Okay, we keep talking about generation ships, but if we are able to approach the speed of light, then time dilation would occur. If the star is within the range of a human lifetime in light years, then wouldn't we be able to travel there in a lifetime if we can approach the speed of light.

Accelerating one ton to one tenth of the speed of light requires at least 125 billion kWh, not accounting for losses.

There is some belief that the magnitude of this energy may make interstellar travel impossible. It is reported that at the 2008 Joint Propulsion Conference, where future space propulsion challenges were discussed and debated, a conclusion was reached that it is highly improbable that humans will ever explore beyond the Solar System. Brice N. Cassenti, an associate professor with the Department of Engineering and Science at Rensselaer Polytechnic Institute, stated “At least 100 times the total energy output of the entire world would be required for the voyage (to Alpha Centauri)”

http://en.wikipedia.org/wiki/Interstell ... lar_travel

So if getting to only 1/10 of the speed of light requires that much energy, imagine how much more would be required to accelerate a ship to relativistic velocities. And then you have the problem of radiation and the abrasion caused by a ship plowing through the interstellar medium. Above .3c, interstellar gas becomes a flow of relativistic nucleons, which is nothing less than hard radiation bombarding the ship and everything aboard. Impacts with micrometeoroids would produce the equivalent energy of an atom bomb. Shielding the ship from these hazards only increases the mass and energy requirements, which are already enormous. Do you see how the problems mount up, the faster you aspire to travel?

Well, yes, I see that these are all technical problems that we haven't conquered. I just believe that we have the ability to overcome pretty much any technical problem we encounter. Do I know of a technology that could do that today? No, but I guess it's a religious belief that we would find a way. I'm willing to accept it isn't logical.

Eddie, thought about this some more. We already have "left" the solar system in a way. Voyager did it. Granted, it took a couple of decades, but I just don't see why we couldn't leave the solar system. Now, if you're saying, leave it and go somewhere else, that is a problem I guess. However, why not shoot for some deep space missions for starters with the goal of moving to the habitable planet over a long period of time?

 

[Shpaget]

You can't rendezvous with an asteriod? How did we land on Eros for the NEAR mission?

Sure you can, I didn't say you couldn't. but you absolutely need to match its speed to land on it.

You would have to expend huge amounts of energy to make incremental changes in an asterioid's path over long distances? I thought we could nudge an asteroid and change its path without a great amount of energy, as long as it is over great distances, as would be travel out of the solar system.

It makes sense only if you don't care where you're heading.
You also need to increase its speed. If it had enough of it, it would leave solar system long time ago.
Changing direction and speed for a spacecraft only is hard and expensive enough. Doing it while dragging a giant rock is impossible.
And like I said, there is absolutely no gain. To get on asteroid you need to approach it on its path (match its velocity). If you can do that, you no longer need an asteroid.

 

[grokme]

You can't rendezvous with an asteriod? How did we land on Eros for the NEAR mission?

Sure you can, I didn't say you couldn't. but you absolutely need to match its speed to land on it.

You would have to expend huge amounts of energy to make incremental changes in an asterioid's path over long distances? I thought we could nudge an asteroid and change its path without a great amount of energy, as long as it is over great distances, as would be travel out of the solar system.

It makes sense only if you don't care where you're heading.
You also need to increase its speed. If it had enough of it, it would leave solar system long time ago.
Changing direction and speed for a spacecraft only is hard and expensive enough. Doing it while dragging a giant rock is impossible.
And like I said, there is absolutely no gain. To get on asteroid you need to approach it on its path (match its velocity). If you can do that, you no longer need an asteroid.

Okay, well if we did it for NEAR, then I don't see why it would be a problem to do it again. Also, I'm not talking about dragging an asteroid around. I'm talking about mining a small asteroid of under 100 M and turning it into a vehicle for space travel. I also don't think it's all that odd an idea to move an asteroid. There have been discussions for years using asteroids for counter balances for space elevators.

 

[MeteorWayne]

Huh? Asteroids, unless they are orbiting the earth (and none are) cannot be used as counterweights for space elevators.

Asteroids are at the most moving at 41 km/sec (vs the earth's ~ 30 km/sec) around the sun at our distance (1 AU)

We don't have the ability to cause any significant change in velocity for even a very lightweight spacecraft after the initial launch...after that it's just tiny course correction maneuvers. For an asteroid the enrgy requirements would be billions of billions of times greater. We have no way to do that.

Totally unrealistic. Sorry,

Wayne the realist.

 

[bdewoody]

This discussion brings to light a point I have been making for quite a while. Unless a means of interstellar travel that bypasses the speed of light and time dilation is discovered and developed I believe we will be limited to observation only of objects and events outside our solar system. If no such invention is forthcoming then I doubt whether we will ever leave this solar system. Maybe, if we survive long enough, when it becomes obvious that our planet or our star is near the end of it's existance we will devote the resources necessary to send a generation ship to a nearby star with potentially habitable planets to start over again. Otherwise getting approval to spend the billions necessary to go to such a system without any material benefit to those who remain behind will never happen.

 

[kelvinzero]

This discussion brings to light a point I have been making for quite a while. Unless a means of interstellar travel that bypasses the speed of light and time dilation is discovered and developed I believe we will be limited to observation only of objects and events outside our solar system. If no such invention is forthcoming then I doubt whether we will ever leave this solar system. Maybe, if we survive long enough, when it becomes obvious that our planet or our star is near the end of it's existance we will devote the resources necessary to send a generation ship to a nearby star with potentially habitable planets to start over again. Otherwise getting approval to spend the billions necessary to go to such a system without any material benefit to those who remain behind will never happen.

Faster than light is almost certainly impossible.

Immortality, electronic storage of personalities and nanomachines that can convert asteroids into anything we wish for free, or grow entire colonies including its human inhabitants from something the size of an appleseed are almost certainly possible.

These violate no physical laws and are really only minor adaptions of the miracles we see living organisms perform every day.

 

[bdewoody]

This discussion brings to light a point I have been making for quite a while. Unless a means of interstellar travel that bypasses the speed of light and time dilation is discovered and developed I believe we will be limited to observation only of objects and events outside our solar system. If no such invention is forthcoming then I doubt whether we will ever leave this solar system. Maybe, if we survive long enough, when it becomes obvious that our planet or our star is near the end of it's existance we will devote the resources necessary to send a generation ship to a nearby star with potentially habitable planets to start over again. Otherwise getting approval to spend the billions necessary to go to such a system without any material benefit to those who remain behind will never happen.

Faster than light is almost certainly impossible.

Immortality, electronic storage of personalities and nanomachines that can convert asteroids into anything we wish for free, or grow entire colonies including its human inhabitants from something the size of an appleseed are almost certainly possible.

These violate no physical laws and are really only minor adaptions of the miracles we see living organisms perform every day.

What do those things have to do with finding habitable planets outside the solar system?

 

[grokme]

Huh? Asteroids, unless they are orbiting the earth (and none are) cannot be used as counterweights for space elevators.

Asteroids are at the most moving at 41 km/sec (vs the earth's ~ 30 km/sec) around the sun at our distance (1 AU)

We don't have the ability to cause any significant change in velocity for even a very lightweight spacecraft after the initial launch...after that it's just tiny course correction maneuvers. For an asteroid the enrgy requirements would be billions of billions of times greater. We have no way to do that.

Totally unrealistic. Sorry,

Wayne the realist.

Fair enough, but what do you mean when you say we don't have the ability to change the velocity for even a very lightweight spacecraft? I'm not sure I'm following what you're saying there. We can't speed up, slow down, etc...? Also, there has been much discussion of how we would deflect an asteroid heading for earth. How would we do that? Not trying to be argumentative. I just don't understand what you're saying when you say we can't move an asteroid or a spacecraft for that matter.

As far as capturing an asteroid, it has been a popular sci fi idea for decades. Arthur Clarke, Kim Stanley Robinson to name a few. Now, I know I'm taking sci fi versus reality, but I'm sure they did a bit of research before throwing those ideas out there.

 

[MeteorWayne]

99% of a spacecraft's velocity is supplied at launch. After that, all you can do is a little tweaking to refine the path, but you're basically committed to going where you are going. You can fine tune things a VERY small amount.

 

[grokme]

99% of a spacecraft's velocity is supplied at launch. After that, all you can do is a little tweaking to refine the path, but you're basically committed to going where you are going. You can fine tune things a VERY small amount.

Okay, I think I understand, and maybe I'm over my head here. You're saying with current technology we can't do it because we don't have the means off planet. I was thinking more of the future when we have the ability to manufacture our own fuel and resources in space. Surely you can change course if you have the stuff up there to do it? It's not a physics question but a resource question, correct?

 

[Shpaget]

Average probe weighs less than one ton.
In comparison a small (spherical) 100 m asteroid would have mass of approx. 1 500 000 tons.
Even if you carve out half of the asteroid, it's still enormous amount of mass to be pushed around.

 

[the_unknown]

The quickest way to get a response, would probably be to send a signal, of all wavelengths that can travel the distance to the 'habitable planet'. The signal would be repeated over and over again stating of the imminent danger that is to come. We would word it something like this "we have created and specialize in 'Planet Buster' technology which has the capability of wiping out any stellar system. The Planet Buster technology is currently being used to clear out the non-living systems, to make communication and travel easier to the inhabited parts of space. This use of this technology is in accordance to MW-Galaxy Policy on Governing Weapons Use, Book 2243P, Page 44326, Revision 14. Please return a signal to allow us to acknowledge your existence by adding your location and technological advancement to our database."

If they received the signal by lets say, radio frequency, I'd bet they would be swarming like angry ants. We could probably hear some type of signal coming back from the distress of the other civilization.

Let's say they have received the signal via microwave (I believe is our fastest type of communication), then we would hear back from them quite quickly. Probably being more advanced than us, would have to ask themselves, why haven't they heard of such policies, and how many other civilizations does their database consist of.

So, either way, quick response, and no chance of starting a war with a more advanced civilization without them knowing who and how many are backing us up in a battle.

 

[grokme]

Average probe weighs less than one ton.
In comparison a small (spherical) 100 m asteroid would have mass of approx. 1 500 000 tons.
Even if you carve out half of the asteroid, it's still enormous amount of mass to be pushed around.

True, and I'm not married to the idea. I was just throwing out something as a possible solution. Since it's already out there in space, and it's already moving at a good clip, and since it is something that has been in space for billions of years and is likely to "travel well", seems like we could leverage it somehow. But if it's not to be, then it's not to be.

 

[grokme]

This discussion brings to light a point I have been making for quite a while. Unless a means of interstellar travel that bypasses the speed of light and time dilation is discovered and developed I believe we will be limited to observation only of objects and events outside our solar system. If no such invention is forthcoming then I doubt whether we will ever leave this solar system. Maybe, if we survive long enough, when it becomes obvious that our planet or our star is near the end of it's existance we will devote the resources necessary to send a generation ship to a nearby star with potentially habitable planets to start over again. Otherwise getting approval to spend the billions necessary to go to such a system without any material benefit to those who remain behind will never happen.

Which is really depressing. It begs the question though. Why look at all if we can never go there? I guess there's something to be learned from the way other planets form. It's basically knowledge for knowledge's sake.

 

[grokme]

So, another dumb question. Are there any stars that are set to approach Sol close enough to be less than a light year? Also, if you rendezvous with a deep space object that is moving towards a distant star, and just parked yourself on it for the ride, would that work?

Lastly, what types of studies could we do of said habitable planet in the future from a distance? I understand we might be able to discern some features, but what kind of things will we be looking at. Climate change models that can be used for our own purposes here on earth? Why are we studying these potential habitable planets, other than to say we found them? What's the benefit?