Earth-like planet

[CrystalTears]

Scientists find most Earth-like planet yet

POSTED: 9:35 a.m. EDT, April 25, 2007

Story Highlights

• NEW: Planet could conceivably house life outside our solar system
• NEW: Discovery a "significant step" on way to finding possible life in universe
• NEW: Planet, dubbed 581 c, orbits red dwarf star Gliese 581
• NEW: Newly found planet full of liquid water, scientist believes

WASHINGTON (AP) -- European astronomers have found the most Earth-like planet outside our solar system, and here's what it might be like to live there:

The "sun" wouldn't burn brightly. It would hang close, large and red in the sky, glowing faintly like a charcoal ember. And it probably would never set if you lived on the sunny side of the planet.

You could have a birthday party every 13 days because that's how fast this new planet circles its sun-like star. But watch the cake -- you'd weigh a whole lot more than you do on Earth.

You might be able to keep your current wardrobe. The temperature in this alien setting will likely be a lot like Earth's -- not too hot, not too cold.
And that "just right" temperature is one key reason astronomers think this planet could conceivably house life outside our solar system. It's also as close to Earth-sized as telescopes have ever spotted. Both elements make it the first potentially habitable planet besides Earth or Mars.

Astronomers who announced the discovery of the new planet Tuesday say this puts them closer to answering the cosmic question: Are we alone?
"It's a significant step on the way to finding possible life in the universe," said University of Geneva astronomer Michel Mayor, one of 11 European scientists on the team that found the new body. "It's a nice discovery. We still have a lot of questions."

There's still a lot that is unknown about the new planet, which could be deemed inhospitable to life once more is learned about it. But as galaxies go, it's practically a neighbor. At only 120 trillion miles away, the red dwarf star that this planet circles is one of the 100 closest to Earth.

The results of the discovery have not been published but have been submitted to the journal Astronomy and Astrophysics.

Alan Boss, who works at the Carnegie Institution of Washington where a U.S. team of astronomers competed in the hunt for an Earth-like planet, called it "a major milestone in this business."

The planet was discovered by the European Southern Observatory's telescope in La Silla, Chile, which has a special instrument that splits light to find wobbles in different wavelengths. Those wobbles can reveal the existence of other worlds.

What they revealed is a planet circling the red dwarf star, Gliese 581. Red dwarfs are low-energy, tiny stars that give off dim red light and last longer than stars like our sun. Until a few years ago, astronomers didn't consider these stars as possible hosts of planets that might sustain life.

The discovery of the new planet, named 581 c, is sure to fuel studies of planets circling similar dim stars. About 80 percent of the stars near Earth are red dwarfs.

The new planet is about five times heavier than Earth, and gravity there would be 1.6 times as strong as Earth's. Its discoverers aren't certain if it is rocky like Earth or if its a frozen ice ball with liquid water on the surface. If it is rocky like Earth, which is what the prevailing theory proposes, it has a diameter about 11/2 times bigger than our planet. If it is an iceball, as Mayor suggests, it would be even bigger.

Based on theory, 581 c should have an atmosphere, but what's in that atmosphere is still a mystery and if it's too thick that could make the planet's surface temperature too hot, Mayor said.

However, the research team believes the average temperature to be somewhere between 32 and 104 degrees and that set off celebrations among astronomers.

Until now, all 220 planets astronomers have found outside our solar system have had the "Goldilocks problem." They've been too hot, too cold or just plain too big and gaseous, like uninhabitable Jupiter.

The new planet seems just right -- or at least that's what scientists think.
"This could be very important," said NASA astrobiology expert Chris McKay, who was not part of the discovery team. "It doesn't mean there is life, but it means it's an Earth-like planet in terms of potential habitability."

Eventually astronomers will rack up discoveries of dozens, maybe even hundreds of planets considered habitable, the astronomers said. But this one -- simply called "c" by its discoverers when they talk among themselves -- will go down in cosmic history as No. 1.

Besides having the right temperature, the new planet is probably full of liquid water, hypothesizes Stephane Udry, the discovery team's lead author and another Geneva astronomer. But that is based on theory about how planets form, not on any evidence, he said.

"Liquid water is critical to life as we know it," co-author Xavier Delfosse of Grenoble University in France, said in a statement. "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."

Other astronomers cautioned it's too early to tell whether there is water.
"You need more work to say it's got water or it doesn't have water," said retired NASA astronomer Steve Maran, press officer for the American Astronomical Society. "You wouldn't send a crew there assuming that when you get there, they'll have enough water to get back."

The new planet's star system is a mere 20.5 light years away, making Gliese 581 one of the 100 closest stars to Earth. It's so dim, you can't see it without a telescope, but it's somewhere in the constellation Libra, which is low in the southeastern sky during the mid-evening in the Northern Hemisphere.

Even so, Maran noted, "We don't know how to get to those places in a human lifetime."

But, oh, the view, if you could. The planet is 14 times closer to the star it orbits. Udry figures the red dwarf star would hang in the sky at a size 20 times larger than our moon. And it's likely, but still not known, that the planet doesn't rotate, so one side would always be sunlit and the other dark.

Two teams of astronomers, one in Europe and one in the United States, have been racing to be the first to find a planet like 581 c outside the solar system.

The European team looked at 100 different stars using a tool called HARPS (High Accuracy Radial Velocity for Planetary Searcher) to find this one planet, said Xavier Bonfils of the Lisbon Observatory, one of the co-discoverers.

Much of the effort to find Earth-like planets has focused on stars like our sun with the challenge being to find a planet the right distance from the star it orbits. About 90 percent of the time, the European telescope focused its search more on sun-like stars, Udry said.

A few weeks before the European discovery earlier this month, a scientific paper in the journal Astrobiology theorized a few days that red dwarf stars were good candidates.

"Now we have the possibility to find many more," Bonfils said.

http://www.cnn.com/2007/TECH/space/04/25/habitable.planet.ap/index.html



NEAT! :D

[Artha]

This is really, really cool. It's only 20 light years away, so it's conceivable that some time within our children's children's lifetimes a human will actually walk around over there.

[Gan]

Very cool.

[Warriorbird]

Showing all the info to the science class I'm subbing for today. The students seem pretty excited.

[Skeeter]

This is really, really cool. It's only 20 light years away, so it's conceivable that some time within our children's children's lifetimes a human will actually walk around over there.

only if you don't believe in physics.

[Parkbandit]

Yea.. we can go there.. if we travel the speed of light, it will take us 20 years to get there.

Currently, we're no where even CLOSE to travelling the speed of light.

[Martaigne]

What? I thought we had warp drives? You mean Star Trek isn't REAL?

:dies:

[Gan]

We have to advance beyond the internal combustion engine first. :(

[Back]

Where can I buy tickets for the cruise?

[Artha]

only if you don't believe in physics.
I doubt we'll ever go faster than light (without finding some colossally awesome way to cheat), but there's no reason to think we can't approach it. Especially with the exponential growth of technology...it's certainly not going to be in our lifetimes, but after all, our grandparents thought the radio was the bees knees and that computers wouldn't ever get much smaller than a house.

[Drew]

only if you don't believe in physics.

1/2 light speed is possible conceptually, perhaps even in the time span Artha mentioned. That would put us there in 40 years. Heck even an ion thruster which is not far off the horizon has a specific impulse of 50k mile per second. Delta-v in a time limit that is acceptable for humans and entering orbit might be the biggest challenges, I don't think Hohmann transfers will work at 1/2 light speed. My guess is that you might be able to "spin down" using the gravity of the entire solar system to orbit down while reversing thrust until Hohmann transfer and possibly aero-braking are possible.

Although I suppose all of this probably depends on cold fusion being mastered to provide an adequate amount of power without having the heat dissipation problems that are likely to plague interstellar travel. I'm not an expert on it but I don't think current nuclear electric propulsion systems can provide near enough power.

[Skeeter]

you also have to be able to withstand that kind of speed.

[Martaigne]

What, no one's invented inertial dampeners either? Human race FTL.


:P

[Hulkein]

you also have to be able to withstand that kind of speed.

The way science advances every day, come on.

[Skeeter]

man I can't even get good cell phone reception half the time.

[The Ponzzz]

Yea I been reading up on this for awhile now.

[Skeeter]

I'm also waiting for my flying cars and hover skateboards that back 2 the future 2 promised me.

[Drew]

you also have to be able to withstand that kind of speed.

Humans can move at any speed, it's how fast they get there that's the problem. For space travel a steady 1g acceleration is probably optimal. I don't know how long 1g acceleration from about 14kps to 1/2 light speed would take, but with the way ion thrusters work this is probably the kind of acceleration they will deliver to begin with.

[Hulkein]

I'm also waiting for my flying cars and hover skateboards that back 2 the future 2 promised me.

That's what makes science funny. People look dumb when they try to predict it.

[Back]

That's what makes science funny. People look dumb when they try to predict it.

Not as dumb as people who deny it. (Vatican)

[Hulkein]

Please shut the fuck up and get the fuck out you troll.

[Tsa`ah]

Heck even an ion thruster which is not far off the horizon

We already have ion propulsion. DS1 was launched in 1998.


specific impulse of 50k mile per second

That's not how ion propulsion works. It's constant thrust that can't be sustained with by conventional chemical propulsion ... yet the rate of acceleration is significantly less than chemical bursts.

The theory (now mostly proven) is that in the vacuum of space, an object propelled by ions will (over time) obtain a higher velocity than any chemically driven object we have sent out ... and only keep accelerating.

A rocket launched from space achieves a velocity of 1kmph after an hour of burning all of it's chemical fuel (example) and maintains a velocity of 1kmph until another force acts upon it.

An ion driven rocket accelerates at 2mph (example) and reaches a velocity of 1kmph after 500 hours and is still ionizing gas for exhaust/thrust and continues to accelerate at 2mph ... reaching 2kmph after 1k hours, 4kmph after 2k hours. It will keep accelerating until it can no longer electrify it's fuel source (xenon in this case) for ions, the gas is no longer able to produce ions for thrust, or until acted upon by an outside force.

The two biggest problems facing ion propulsion for human transportation in space are course correction and stopping ... both are huge when you consider you're trying to launch from a small dot in an almost infinite space in an attempt to hit another small dot.

[StrayRogue]

Yes I remember reading/watching about the ion drive on the news at the time. Apparently it's initial thrust is space was akin to a man blowing against the edge of a sheet of paper. However, as Tsa points out, it's the constant acceleration that makes it viable eventually.

[Drew]

Sorry if my post wasn't terribly clear Tsa'ah, I'm relatively aware of how ion propulsion works. You are talking about accelerating something over a period of time which, of course, you need if you are sending humans. My understanding is that the process is more efficient, uses less fuel, accelerates slower (than a heavier chemical rocket) but has a great top speed.

[Drew]

Also there's no reason you couldn't have boosters like the shuttle uses for leaving earth. I'm just assuming that whatever vessel we built would be built in space, but it certainly seems like you could build a chemical booster, mass driver, beam propulsion, something to get it going to a reasonable pace quickly.

[Skeeter]

seriously though, we'd have to have more dedication to the "space race" We "probably" put a man on the moon almost 40 years ago. We have barely been back and we still haven't put a man on Mars yet.

AFAIK there haven't been major changes to the space shuttle program in the last 20 years or so. Granted I'm not too studied up on the subject so maybe one of our nasa interns can fill me in.

[Back]

All very true. Maybe this will be the impetus that fuels the drive for the next “space race.” At least, we can hope it will be.

[Latrinsorm]

An ion driven rocket accelerates at 2mphThis should read "mphph", as long as we're being precise about things.
The two biggest problems facing ion propulsion for human transportation in space are course correction and stopping As you've noted, the whole point of ion thrusters is that they have very low rates of acceleration for the craft that are spread out over a heck of a long time. This makes it really easy to correct course compared to trying to correct it after you've burned all your fuel: just fire off a couple ions!
Also there's no reason you couldn't have boosters like the shuttle uses for leaving earth.You actually have to have conventional fuel to leave the earth. Ion thrusters only work once you get into orbit.
AFAIK there haven't been major changes to the space shuttle program in the last 20 years or so.The next program (this is just what I heard colloquially) is like Gemini/Apollo on steroids.
All very true. Maybe this will be the impetus that fuels the drive for the next “space race.” At least, we can hope it will be.I'd rather hope governments increase funding for this earthlike planet rather than some n00b red giant one. L2rotate.

[StrayRogue]

You actually have to have conventional fuel to leave the earth. Ion thrusters only work once you get into orbit.

Yes, but, as he said, if it's constructed in space, you could still add conventional rockets/boosters to it for an initial burst of speed.

[Stanley Burrell]

We have to advance beyond the internal combustion engine first. :(

How we done gawn scout it out for oil then? :-P

[Martaigne]

I'd rather hope governments increase funding for this earthlike planet rather than some n00b red giant one. L2rotate.

I concur.

[Tsa`ah]

This should read "mphph", as long as we're being precise about things.

No one was being precise about anything, otherwise I would have stated the rate of acceleration as 1.06mph.

Using mphph is nothing more than idiotic redundancy ... that's why I noted as mph ... because mph was precise enough.


This makes it really easy to correct course compared to trying to correct it after you've burned all your fuel: just fire off a couple ions!

No.

In the early stages of acceleration sure, but that's more than a few ions. DS1 required several hours of redirecting it's drive output to make very minor course corrections and NASA kept it's speed reigned in at a paltry 900-1000mph.

Imagine ... no, nevermind you can't ... a similar drive operating for an entire year (we're talking a speed of around 9.3k mph).

Considering the distance from point a to point b and the velocity after 1 year of constant operation ... corrections are more than a few ions, rather days of correction, if not weeks or longer.


I'd rather hope governments increase funding for this earthlike planet rather than some n00b red giant one. L2rotate.

You take what you can get. If it can sustain life enough to fit basic human needs, you go for it.

Humanity can't be the picky new socialite bride looking for her first home at the expense of her husband's sanity. We don't have that luxury.

[Celephais]

Using mphph is nothing more than idiotic redundancy ... that's why I noted as mph ... because mph was precise enough.

While I agree there is no need to nitpick over it... mph is not precise enough, otherwise people would just say "yeah he was speeding, going 70 miles". Because you can accelerate at 1 mphps too. (and I know you know this, I'm just saying it's not redundant).


In the early stages of acceleration sure, but that's more than a few ions. DS1 required several hours of redirecting it's drive output to make very minor course corrections and NASA kept it's speed reigned in at a paltry 900-1000mph.

Imagine ... no, nevermind you can't ... a similar drive operating for an entire year (we're talking a speed of around 9.3k mph).

Considering the distance from point a to point b and the velocity after 1 year of constant operation ... corrections are more than a few ions, rather days of correction, if not weeks or longer.

Sure you can't course correct to dodge some asteroid, but I really don't think course correction between one star and another is a big deal... any trip from point A to point B using (only a steady) ion thrust will require you start slowing down half way, so as long as you're constantly tracking your target, it shouldn't be a big deal, despite going really fast and not having much "influence" on the course correction when you're near the midpoint, you still have a lot of time to correct, and as you get closer, you have more influence to correct.

[StrayRogue]

The chances of hitting an asteroid, even in an asteroid field, are incredibly remote. However there could be and would be causes for corrections to be remade.

[Gan]

While I agree there is no need to nitpick over it... mph is not precise enough, otherwise people would just say "yeah he was speeding, going 70 miles". Because you can accelerate at 1 mphps too. (and I know you know this, I'm just saying it's not redundant).



Sure you can't course correct to dodge some asteroid, but I really don't think course correction between one star and another is a big deal... any trip from point A to point B using (only a steady) ion thrust will require you start slowing down half way, so as long as you're constantly tracking your target, it shouldn't be a big deal, despite going really fast and not having much "influence" on the course correction when you're near the midpoint, you still have a lot of time to correct, and as you get closer, you have more influence to correct.

Lets not forget that point B in the examples given are not stationary, but orbiting. Not to mention that there could be large objects that, while not in the direct path of the line to point B, might have orbital paths at some point in time that move through the line to point B.

Talk about a headache to plot out. Its one thing plotting out within the same solar system. Its another huge story when you're involving travelling through to different solar systems (or even galaxys in some instances).

[Celephais]

Lets not forget that point B in the examples given are not stationary, but orbiting. Not to mention that there could be large objects that, while not in the direct path of the line to point B, might have orbital paths at some point in time that move through the line to point B.

But by the time you reach point B you're going pretty slow... and besides the planet has a small orbit around a star (stars are for our purposes, stationary), I think you can shoot for wherever the planet was and use conventional thrusters once you get there to hit your mark.


Talk about a headache to plot out. Its one thing plotting out within the same solar system. Its another huge story when you're involving travelling through to different solar systems (or even galaxys in some instances).

I hardly doubt you will need to travel through another solar system to reach this one, considering it's a "close" solar system, and that (again solar systems being "stationary") if it were behind another solar system I doubt we'd have the data we have on it. I would be willing to bet that no two solar systems are in a direct path from our solar system within our galaxy. The purportions of the solar system, and the craft, to the void makes it statistically impossible.

[Tsa`ah]

But by the time you reach point B you're going pretty slow... and besides the planet has a small orbit around a star (stars are for our purposes, stationary), I think you can shoot for wherever the planet was and use conventional thrusters once you get there to hit your mark.

Just imagine how long it's going to take to decelerate to "pretty slow".

[Celephais]

Just imagine how long it's going to take to decelerate to "pretty slow".

Okay, now you're looking like an idiot.

Exactly the same amount of time it took to accelerate to "pretty fast". That's why I said that half-way through the journey you reverse your thrusters (well I didn't say it exactly like that, but I said you will have to start slowing down). You don't exactly expect us to arrive at our destination going half the speed of light do you? won't exactly get too good a view from that speed.

[Gan]

Definately slower than Capt. Kirk's standards.

[Gan]

So if you travel at the speed of light, and you have your headlights on, will you still be able to see in the dark?

[Celephais]

So if you travel at the speed of light, and you have your headlights on, will you still be able to see in the dark?

While I know you're joking, there was a post someone had a while ago with a video explaining the theory of relativity really well (IE with cartoons). And that despite the fact you're still going light speed, all light still travels at light speed relative to you by fucking with time... so yes.

[Tsa`ah]

Okay, now you're looking like an idiot.

Exactly the same amount of time it took to accelerate to "pretty fast". That's why I said that half-way through the journey you reverse your thrusters (well I didn't say it exactly like that, but I said you will have to start slowing down). You don't exactly expect us to arrive at our destination going half the speed of light do you? won't exactly get too good a view from that speed.

I'm starting to sound like an idiot? Please.

You're making statements that lack any type of research. Do you know what lies between point a and point b? To state that there's no other solar system in between is more or less pulling a statement from your ass.

Why in the hell would you start slowing down at the halfway point if you're going to use chemical fuel to achieve orbit?

Ion propulsion is probably the best bet for accelerating to the desired velocity, but it would be pretty ignorant to use it as a breaking system if you plan on using chemical propulsion later on in the trip.

"Hey, let's add more time on to this trip than we need to .... let's not use anything but ion propulsion until we're within range to use nothing but chemical."

Use your head for something other than a place holder for your ears.

[Celephais]

I'm starting to sound like an idiot? Please.

You're making statements that lack any type of research. Do you know what lies between point a and point b? To state that there's no other solar system in between is more or less pulling a statement from your ass.

You're drawing a line that is the radius of a spacecraft thick from Earth to 20 light years away, I'd bet everything I own there is nothing in the way of this solar system and that one, it's statistics, it's math.


Why in the hell would you start slowing down at the halfway point if you're going to use chemical fuel to achieve orbit?

Ion propulsion is probably the best bet for accelerating to the desired velocity, but it would be pretty ignorant to use it as a breaking system if you plan on using chemical propulsion later on in the trip.

Now you're looking like an idiot again. It takes exactly the same amount of energy to go from 1000mph to 0 as it does to go from 0 to 1000, if you could decelerate so easily, why wouldn't just just accelerate the same way?

[Stanley Burrell]

From an astrobiological and free time today perspective:

Wouldn't someone who was a dedicated Star Trek next generation born-in-space space baby have a heart so ridiculously small that coming within moon gravity would warrant, sort of, immediate cardiac arrest? That's less of a G-suit and more of a bodybag.

Plus: How inda hell could you ever conduct the plausability of performing an in space repair test at tenths of light speed if you can't exactly send any sort of data back to the homeworld? Would we try making quasi-light speed shuttles to orbit Earth at first? Howzitgo, my astrophysicists?

[Tsa`ah]

You're drawing a line that is the radius of a spacecraft think from Earth to 20 light years away, I'd bet everything I own there is nothing in the way of this solar system and that one, it's statistics, it's math.



Now you're looking like an idiot again. It takes exactly the same amount of energy to go from 1000mph to 0 as it does to go from 0 to 1000, if you could decelerate so easily, why wouldn't just just accelerate the same way?

Say whahuh?

No one mentioned required energy ... I merely pointed out how idiotic you were to suggest ion propulsion be used as the sole means of breaking (decelerating).

Chemical bursts of thrust would be the optimal (current technology) considering time would be a huge factor.

Why slow down at 2mph when you can slow down at 6000mph? Why potentially double the length of a one way trip? It's idiotic.

No one but you threw out energy ... which has almost no factor in the discussion.

On what lies between point a and b is nothing more than assumption, largely on your part. Mathematic probability doesn't cut it.

[Drew]

The worry about deceleration is with humans aboard you can't decelerate very quickly so using a chemical rocket to decelerate would probably be impractical. You can't put humans through sustained "heavy" g-loads for an appreciable period of time.


Here's a thought for deceleration, let me know what you guys think. Since we hopefully have a pretty decent source of power on board why not have a mass driver onboard for sudden deceleration. Would it be possible to put humans in some sort of sealed room in a solution (think jello, but more viscous) and have the mass driver fire off a large part of the ship (maybe 30% of the total weight) to handle a good part of the deceleration at once. This would cut a lot of time off the journey. Humans can go through high G loads for short periods of times (race drivers crash into walls at over 150 Gs for about a second with just restraining belts). If you have them in an inflated G suit type thing while you put them in a solution this would act as an inertial damper and you could bleed off a lot of speed at once.


Also, if this were a two way journey, it wouldn't be hard to get the mass back for using a second shot of the mass driver on the return to earth. With chemical rockets you'd need to carry enough fuel for firing it when you got to the new planet and then when you returned to earth, or you'd have to have a manufacturing plant on board.

[Tsa`ah]

It would be ideal to decelerate with chemical fuel in the form of a solid and/or liquid rocket booster ... but it would have to be in short bursts over a period of time.

[Gan]

I personally think you're trivializing the computations necessary to interpret and anticipate any and all objects that have orbital/travel paths that intersect your line from point A to point B, especially at estimated times over a span of 20 light years time/distance.

[Drew]

I personally think you're trivializing the computations necessary to interpret and anticipate any and all objects that have orbital/travel paths that intersect your line from point A to point B, especially at estimated times over a span of 20 light years time/distance.

Outside of a solar system deep space is very empty Ganalon. You have a few rogue objects, maybe even rogue planetoids but that's about it, and in the scale of things your chance of running across one of them is probably too minimal to compute. In fact, if we aren't on-axis with this other solar system there probably isn't much at all we could hit once you clear the oort cloud.

[Celephais]

You're drawing a line that is the radius of a spacecraft thick from Earth to 20 light years away, I'd bet everything I own there is nothing in the way of this solar system and that one, it's statistics, it's math.

Decided to pull up some facts for you:
There are 40 stars within 16 light years of the Earth.
http://hyperphysics.phy-astr.gsu.edu/hbase/starlog/strclos.html

Since we're talking a sphere expanding to 20 light years is approximately doubling the volume. Let's just work with a constant density for the sake of this example, 80 stars... when identifying a ray from a point you use two angles, giving you 129600 one degree by one degree pyramids shooting off of earth...

The volume of space in a 20 light year radius is ~33,510 cubic light years, or 6.807 X 10^42 cubic miles. we've got 80 stars in there.

Lets just say for the hell of it that our ray we're drawing from earth has a radius of oh... a million miles.. nah, a billion miles.. so we're never more than a billion miles off course on average. This makes our ray have a volume of 3.696 X 10^32 cubic miles (that's way way way over what it should be). So we're going to "travel" through one 1.8417 X 10^10th of the volume... so we have a 1 in 230,212,500 chance of this MASSIVE 1 billion mile radius ray passing through a star (yes I know I didn't account for the volume of the stars, but that's insignficant).

And I highly doubt we'd have any info on this solar system if there was another in the way, the interference would wreck any data we had.

[Tsa`ah]

That is again, assumption.

Relying on assumption based on numbers is far too risky considering we have very little data on the space in between.

[Drew]

We could also hit Nemesis.

[Drew]

That is again, assumption.

Relying on assumption based on numbers is far too risky considering we have very little data on the space in between.



I don't know what you mean about having very little data. Do you think the space in between here and 20 light years away is full of blackbodies?

[Celephais]

Say whahuh?

No one mentioned required energy ... I merely pointed out how idiotic you were to suggest ion propulsion be used as the sole means of breaking (decelerating).

Chemical bursts of thrust would be the optimal (current technology) considering time would be a huge factor.

Why slow down at 2mph when you can slow down at 6000mph? Why potentially double the length of a one way trip? It's idiotic.

No one but you threw out energy ... which has almost no factor in the discussion.

On what lies between point a and b is nothing more than assumption, largely on your part. Mathematic probability doesn't cut it.

Do you not understand physics? It's EXACTLY the same to accelerate as to decelerate. If you're saying we should plan to decelerate from 6000mph when we get there, why wouldn't we accelerate chemically to 6000mph from the start? Hell it would reduce the mass we're trying to accelerate/decelerate later, would make more sense to do it at the start. The whole reason to use ion thursters is an energy issue, if energy wasn't the issue (in the form of fuel) we'd just chemically accelerate and decelerate the whole way.

Course correction at the end of the trip is a non-issue.

[Gan]

I don't know what you mean about having very little data. Do you think the space in between here and 20 light years away is full of blackbodies?

How can you be 100% sure that space between here and anywhere for 20 light years time/distance has exactly what you perceive it to have now, through theoretical computations and/or best guess technology of a civilization that is so young and so inexperienced with space that there's really no solid proof to back said theories up?

[Tsa`ah]

hahahaha ..

No, I mean we haven't looked at it with any interest.

Hell, just look at the original article in the first post of this thread. No one really looked at red dwarf systems for life or life supporting planets. It took finding one possibility before more people started looking at systems they passed over for decades because they were wrong.

You can assume the space in between is empty or devoid of enough obstructing material to believe it's mathematically improbable that anything will intersect the line from a to b ... but that's only because we don't look at empty space ... we have VERY LITTLE DATA ON IT because it has held little to no interest.

You can bet your ass that we'll be sending all sorts of unmanned craft to collect data on the path before anything living is sent in an effort to ensure there is nothing there.

[Celephais]

That is again, assumption.

Relying on assumption based on numbers is far too risky considering we have very little data on the space in between.

Far too risky? What the... What do you think the space program is? Everything has a chance of failure, the chance of something being between our SS and the one with this planet is so fucking remote it's laughible, I don't think you understand the scale we're talking about here...

[Drew]

How can you be 100% sure that space between here and anywhere for 20 light years time/distance has exactly what you perceive it to have now, through theoretical computations and/or best guess technology of a civilization that is so young and so inexperienced with space that there's really no solid proof to back said theories up?


I'm certainly not 100% sure, in fact our understanding of how space works is very limited and held together by band-aid theories (dark matter, etc.). Anyway, I don't doubt we'll be sending probes first like Tsa'ah said, but I'm personally all for getting some portion of humanity off this planet as soon as possible. Columbus and company had a belief that they would make it to India before food/water ran out (this may not be the best example, because they wouldn't) but I wouldn't mind seeing some intrepid attitude with something like this.

[Drew]

the chance of something being between our SS and the one with this planet is so fucking remote it's laughible, I don't think you understand the scale we're talking about here...


QFT, I don't think most people understand how vast a scale we are talking about because we have no method for comparison.

[Tsa`ah]

Do you not understand physics? It's EXACTLY the same to accelerate as to decelerate. If you're saying we should plan to decelerate from 6000mph when we get there, why wouldn't we accelerate chemically to 6000mph from the start? Hell it would reduce the mass we're trying to accelerate/decelerate later, would make more sense to do it at the start. The whole reason to use ion thursters is an energy issue, if energy wasn't the issue (in the form of fuel) we'd just chemically accelerate and decelerate the whole way.

Course correction at the end of the trip is a non-issue.

Are you retarded or do you work for it?

We wouldn't use chemical propulsion for a number of reasons.

1. Cost
2. Inability to sustain long term thrust
3. Completely lacks any semblance of efficiency
4. Bulk

No one is arguing energy, unless you count yourself ... and it's completely moronic to argue with yourself.

It takes the SAME energy sure ... we're talking about time.

Let's say it's a straight line.

------------/------------

This is what you're talking about. The / represents the point in which you suggest deceleration occurs ... which is MORONIC when you can use the same amount of energy, yet more of it in bursts over a SHORTER period of time to decelerate. The above would represent at least a 20% or longer increase in travel time ... which you want to avoid with living passengers.

----------------/-/-/-/-/-

This would be representative of using chemical bursts, using the SAME AMOUNT OF ENERGY in HIGHER QUANTITIES over a SHORTER SPAN OF TIME AND DISTANCE than an ion propulsion system could produce. The above represents the same distance traveled in a shorter span of time which is IDEAL for travel with living passengers.

Course correction is a non-issue assuming all of your assumptions are correct.

We really don't know what lies between point a and point b. Anything that got close enough to influence the craft with a gravitational pull would require a course correction.

[Tsa`ah]

Far too risky? What the... What do you think the space program is? Everything has a chance of failure, the chance of something being between our SS and the one with this planet is so fucking remote it's laughible, I don't think you understand the scale we're talking about here...

You're comparing vegetation to minerals.

I understand the scale and I also understand that our points of interest to this point have not been what we believe to be empty space.

The space program to date has dealt with at least a few known and accepted facts. Gravitational pull, thrust ... so on and so forth.

We theorized and proved that space would be a near vacuum based on what we did know. We don't look into empty space because as I have said enough times ... it doesn't hold any interest. We assume, based on the statistics we do have, that there's very little there.

What we do know about empty space is that there's very little there that we can DETECT and it has been assumed from that point on that the information we do have is good enough for now. And it is good enough for now because empty space is of little use to us at this point.

When the possibility arises that we may be able to send manned craft beyond our little system ... we will look into empty space to see what is there.

Mathematic probability based on little to no data is not even worth risking unmanned craft on except for the express purpose of gathering FACTS on empty space.

[Drew]

----------------/-/-/-/-/-


To be pedantic we'd want something more like:


\-\-\-\-\--------------/-/-/-/-/-



The question is could we make a ship capable of going that fast while carrying all the chemical fuel needed. (It would have to be a massive massive ship).

[Tsa`ah]

Why would you shut off an ion drive well before the halfway mark.

The point of it is to obtain a higher rate of speed than current conventional means.

Other than that ... here's your empty "interstellar" space.

http://history.nasa.gov/EP-177/ch4-6.html

[Stanley Burrell]

The worry about deceleration is with humans aboard you can't decelerate very quickly so using a chemical rocket to decelerate would probably be impractical. You can't put humans through sustained "heavy" g-loads for an appreciable period of time.


Here's a thought for deceleration, let me know what you guys think. Since we hopefully have a pretty decent source of power on board why not have a mass driver onboard for sudden deceleration. Would it be possible to put humans in some sort of sealed room in a solution (think jello, but more viscous) and have the mass driver fire off a large part of the ship (maybe 30% of the total weight) to handle a good part of the deceleration at once. This would cut a lot of time off the journey. Humans can go through high G loads for short periods of times (race drivers crash into walls at over 150 Gs for about a second with just restraining belts). If you have them in an inflated G suit type thing while you put them in a solution this would act as an inertial damper and you could bleed off a lot of speed at once.

You'd probably have to use an ultra low-density liquid that could and would have to span for quite a great distance for *each* human being aboard the Enterprise space rental vessel.

That would mean, I think, literally stocking a space dock, or two jillion, with said space airbag gel and then having to go through the tedious process of creating some kinda bay, maybe, where it'd gyroscope to a precise density of each human being so as to get as close to a perfect "line" of inertia and, um, not "sharp" kinetic aborption distributed evenly through each passenger's body.

I kind of think of it like jumping off the tallest bridge in the world and replacing the water below with super light immersion oil thereby surviving the (initial) impact.

Something.

[Celephais]

Why would you shut off an ion drive well before the halfway mark.

The point of it is to obtain a higher rate of speed than current conventional means.

Other than that ... here's your empty "interstellar" space.

http://history.nasa.gov/EP-177/ch4-6.html

You're grasp of physics and calculus is disheartening.

Velocity is the area under the graph of acceleration over time, displacement is the area under the graph of velocity over time. This is calculus, these are intergrals. Graph it out, take an excel sheet and do the math... say you have an ion thruster that produces 1mphph, and enough chemical fuel on a ship to produce 5mphph sustained for 5 hours, and you need to go 2,500 miles and be going 0 mph at the 2,500 mile mark. We'll ignore the mass of the chemical and it's effects on inertia.

If you just use the ion thrusters only, you will accelerate for 50 hours, reach 50mph at 1250 miles, and then have to reverse the thrusters, travel another 50 hours, to be going 0mph at 2,500 miles hour 100.

If you blow your chemical load ASAP, you'll travel for 32.5 hours and reach mile marker 1125 @ 52.4mph before you have to turn the thrusters around if you want to stop in time, stopping at hour 84.88.

If you decide to hard break when you get there, you will travel for 52.4 hours, reach marker 1375 @ 52.4mph, and then reverse, reaching 0mph at hour 84.88

If you ion thrust, hard chemical break, and then ion reverse the rest of the way... in 58.47 hours you will reach marker 1709.8 hard chem break for 5 hours, decelling to 33.47mph, then ion reverse to 0 at 96.95 hours

If you use half your chems, then ion halfway, ion reverse, then use the other half of the chems for when you get there as Drew said, you make the best time, reaching 1250 in 41.2 hours before reversing thrusters, and 2500 in 82.47 hours. Note you begin decelerating AT THE MIDDLE OF THE TRIP.

your stutter breaking idea is just retarded... but why not I'll do it out, lets say you plan to stutter hour long chem breaks between 2 hour ion breaking. So you ion up to 53.198 mph in so many hours, reaching mark 1415, then you start ioning back down till you reach 33mph at mile mark 2285.5, then you fire up the chems for an hour, then ion for 2, chems ion like a fucking idiot until you stop at hour 86.39.

You lose, thanks for playing.

[Celephais]

Here's a thought for deceleration, let me know what you guys think. Since we hopefully have a pretty decent source of power on board why not have a mass driver onboard for sudden deceleration. Would it be possible to put humans in some sort of sealed room in a solution (think jello, but more viscous) and have the mass driver fire off a large part of the ship (maybe 30% of the total weight) to handle a good part of the deceleration at once. This would cut a lot of time off the journey. Humans can go through high G loads for short periods of times (race drivers crash into walls at over 150 Gs for about a second with just restraining belts). If you have them in an inflated G suit type thing while you put them in a solution this would act as an inertial damper and you could bleed off a lot of speed at once.

Carrying 30% of your mass as "dead weight" (if it's not mostly composed of consumed waste on the way there) means you're effectively carrying 30% of additional inertia, which is just going to mess up the whole thing... but...

Given that I just showed using half your chemicals for accel and half for decel is the way to go, you would want a way to handle those Gs for acceling too, but since we can't reverse your idea, what happens if you figured out a way for humans to handle 10mphph of decel and plugged it into the "ion/rev-ion/chem break" model.

you would ion up to 52.739 mph, then start ioning down, then chem we burn the chems twice as fast/hard to produce 10mphph of reverse thrust for 2.5 hours. You would reach your goal in 82.978 hours... better than before, but still slower than if you just used half your chems at either end at half the Gs.

And plugging it into the "best" model, saying Chem 5mphph (2.5 hours), then ion, then ion reverse, then Chem reverse 10mphph(1.25 hours) you would get:
81.63 hours to reach your dest. I could probably play with how long you chem up/chem down to get there slightly faster, but I don't feel like messing with it...

[Celephais]

Other than that ... here's your empty "interstellar" space.

http://history.nasa.gov/EP-177/ch4-6.html

What the... you think that helps your point? We were talking about hitting something that could damage a spacecraft...

Did you bother to read that? It's an "almost perfect vaccuum", so our spacecraft going to colide with singular atoms, do you know what that'll do? Nothing, absolutely nothing. Any atoms it hits will offer "resistence" in the form of inertia, but the mass of our spacecraft will easily make up for colliding with a single atom. If anything these just enforce a cap on that max speed our spacecraft can reach.

[Ignot]

How much would it suck to spend 40 years to start new life on a planet and then you get there by some miracle but crash on the landing and die.

[Jayvn]

I heard gsVII was going to release breakage to celebrate the day we land on the new planet.

[Warriorbird]

Uh oh! Math fight!

[Ignot]

I heard gsVII was going to release breakage to celebrate the day we land on the new planet.

This made me laugh

[Celephais]

Uh oh! Math fight!

Hahaha, my girlfriend asked me how my day was, I said "I got in a math fight" (and I hadn't even seen this post yet). Awesome.

[Gan]

Reading this thread has suddenly given me the urge to put all my pens in a pocket protector.

Now where's my calculator???

[Drew]

Carrying 30% of your mass as "dead weight" (if it's not mostly composed of consumed waste on the way there) means you're effectively carrying 30% of additional inertia, which is just going to mess up the whole thing... but...


I don't have any exact figures of course but I think you'll be carrying at least 30% of your total mass in fuel for a chemical deceleration. Mass driver has the benefit of slowing down quicker, you can expel as much mass as you'd like in ultra quick bursts which are more compatible with the human body than the more extended burns you need for a solid fuel rocket.




since we can't reverse your idea


Mass drivers work both ways, but since you've thrown off the weight to get started it's irrelevant for considering braking.

[Celephais]

I don't have any exact figures of course but I think you'll be carrying at least 30% of your total mass in fuel for a chemical deceleration. Mass driver has the benefit of slowing down quicker, you can expel as much mass as you'd like in ultra quick bursts which are more compatible with the human body than the more extended burns you need for a solid fuel rocket.

Which is why it would be silly to carry fuel for anything other than navigating around when you get there. Considering that the majority (99+%) of your acceleration is going to come from the ion thruster in a 20 light year trip, you really improve your time by reducing mass and thus making your ion thruster capable of producing more acceleration.


Mass drivers work both ways, but since you've thrown off the weight to get started it's irrelevant for considering braking.

If it works both ways (I don't know too much about mass drivers, I had thought they were more like electric rail guns) then clearly the best way to do it is to accelerate as quickly as posible to start, and then decelerate as quickly as possible at the end.

[Ignot]

I don't understand what the fuck you guys are talking about in this thread but im quite sure you all got beat up in middle school.

[Celephais]

I don't understand what the fuck you guys are talking about in this thread but im quite sure you all got beat up in middle school.

... why didn't you just say:
http://i169.photobucket.com/albums/u222/GuinnessKMF/Nerds.jpg
Prepare for a moon spanking!

[Gan]

.

http://thor.mirtna.org/features/titular_movie_themes_rotn_small.jpg

[Slark]

Imagine how frustrating it'll be for the people on earth when the date comes that the spaceship is scheduled to land on the planet and we'll have to wait another 20 years to know what happened.

[Ignot]

... why didn't you just say:
http://i169.photobucket.com/albums/u222/GuinnessKMF/Nerds.jpg
Prepare for a moon spanking!

Celephais wins this thread

[Gan]

Farakahn already knows about the spaceship.

[Drew]

BTW, I think we'll be going to alpha centauri first. Odds are extremely good that there are rocky planets there, but probably no gas giants. And it's only 4 light years away.