Interstellar Probes - Current Capabilities

[dragon04]

<font color="yellow">If the probe doesn't have to stop at the target system, the sail only has to last for the acceleration phase. After that, disconnecting it or reeling it in might be a good idea.</font><br /><br />I don't think that an interstellar "fly-by" mission would be practical or cost-effective.<br /><br />Considering the expenditure and required resources, such a mission couldn't possibly return too much meaningful data.<br /><br />Again, an Orion style nuclear pulse type mission could fly to Alpha Centauri and return in under a century and spend a few years gathering data.<br /><br />The biggest problem of <b>any</b> interstellar mission would be the degree of automation and AI that such a probe would require. A 4 year time lag between instruction and execution would be prohibitive in and of itself.<br /><br />At the implied velocities, course corrections that take even weeks or months to be received from any Ground Control would be fruitless.<br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[nexium]

About 140 years ago we built sailing ships with as many as 4 masts, but not 5. I'm not sure of all the reasons, but some of them likely sort of apply to the solar sail. Increased area of sail means the masts and booms that transfer the push of the sail to the spacecraft get longer ( partly to minimize one sail shading the others) and thus more fragile, unless their mass is increased greatly.<br />CNT = carbon nano tubes with great specs will allow more solar sail area, before deminishing returns make bigger and more impractical. Neil

 

[3488]

It is very highly possible Joel.<br /><br />If like Jupiter & formed around our sun, would it be detectable in IR from the Spitzer?<br /><br />IMO, Jupiter would have been found by now if were that far away.<br /><br />Perhaps a rogue Jupiter type Gas Giant, wrenched from a much older Solar system <br />(so is now pretty cold), that is orbiting the galactic centre with its own system of moons,<br />yes, very exciting. Particularly if those moons are large,<br />icy with rocky cores / mantles,<br />undergoing tidal heating (sounds familiar), yes what a find. Think of what we could learn.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[emperor_of_localgroup]

Another facet of space exploration I think you all are ignoring. That is our telescope technology. Before our technology allows us to reach .1c speed, I have a strong feeling, our telepscope technology will make it possible to watch Alpha Centauri like Google Earth - down to their driveways, if there is any. <br /><br />Unfortunately telescope technology's pace is very slow. We have been playing with lenses and mirrors for too long, time to look into other materials or processes. After all, its all in focal lengths. <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[tdamskov]

A fly-by mission is probably the only realistic kind of mission with current technology. You're right that this leaves only a few weeks passing through the target system, but the observations made should still be orders of magnitude more detailed than anything possible with telescopes.<br /><br />Perhaps the solar sail fly-by probe should be considered the precursor to a followup Orion capable of stopping in the system as well as proof-of-concept of the technology? Considered as a single mission it probably wouldn't be cost effective in any way.

 

[MeteorWayne]

Even then, how much are you going to see flying by at 0.1C?<br /><br />That means you cover the distance from the earth to the sun in 80 minutes. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[h2ouniverse]

Hi Andrew,<br /><br />The point for detection of a large distant captive or free planet is that:<br />* if the upper atmosphere is very cold: you need a FIR space telescope + a methodic sky survey. I am not sure Spitzer would be able to detect a cold Jupiter at say less than 25000AU... and even so, is Spitzer really devoted to this kind of survey?<br />* an object as bright as 2005FY9 (mag 17 in visible!!) had to wait until 2005 to be detected at just 52 AU; the FIR magnitude is probably quite high as well. And yet... The TNO searchers pretend they have scanned the entire ecliptic and yet they miss about 30% of it!!! Let alone higher inclinations.<br /><br />I hope Gaia will help once launched.<br /><br />Btw, I wonder which surface conditions a realtively young free big Earth would give (say 5 Earth masses...). Its core should still be molten and evacuate several W/m² through a very thin crust. If the atmophere is thick enough to insulate and keep warm temperatures by pressure effect, what would be the surface temperature?<br /><br />Cheers

 

[franontanaya]

Actually, Spitzer did found a pair of brown dwarves, 400 l.y. away:<br /><br />http://www.space.com/scienceastronomy/060803_planemo_twins.html<br /><br />Wikipedia reports 57 and 20 Jupiter masses, though:<br /><br />http://en.wikipedia.org/wiki/Oph_162225-240515<br /><br />Spitzer couldn't spot 90377 Sedna when they tried, that may give an idea of its limits. <br /><br />Maybe Kuiper belt objects could be good interestellar probes themselves to find rogue planets within a few thousands AU that may modify their orbits. If we manage to track them all the way to the aphelium. <br /><br />It's obvious that if we just found Eris and Sedna under 100 AU, there may be a lot of big Kuiper bodies now wandering the nearby interestellar space. <div class="Discussion_UserSignature"> </div>

 

[h2ouniverse]

I was aware of the brown dwarves spot by Spitzer. But to me this is not resulting from a methodic search, and also these two bodies are very hot, so they radiate in NIR not FIR.<br /><br />In reply to :"I think it's quite sure if we just found Eris and Sedna close to their perihelium, there may be a lot of big Kuiper bodies now wandering the nearby interestellar space."<br />--------------<br />Sure! Mike Brown's team should announce tens of dwarf-planet-sized bodies quite soon now. And that is just in KB and Outer Belt. They are searching now up to 1000AU (but they still miss chunks of the ecliptic)<br /><br />Current models predict one planetary body out of two is ejected from its star's central area during its life. So the Milky Way should be theoretically full of wanderers...

 

[3488]

AFAIK, many planetary objects are chucked out during the formative period<br />when there are a large number, jostling around, undergoing many close encounters, <br />resulting in planets, asteroids & comets being ejected.<br /><br />IMO, intersteller planets, comets & asteroids are as common as muck.<br /><br />But as been pointed out, they are likely to be sooooooooo cold, that only FIR<br />telescopes will find them, unless one passes through our solar system.<br /><br />I wonder if this may have happened about 1GYA, when the Jupiter moon Ganymede appeared<br />to undergo rejuvenated temporary activity.<br /><br />Looking forward to Mike Brown's announcement.<br /><br />I wonder if Eris will be knocked off the top spot in size & mass?????<br /><br />90377 Sedna, yes I remeber that failed observation with Spitzer. Sedna being relatively <br />small & so far away, even Spitzer could not pick up its IR emmissions. Shows how cold Sedna is.<br /><br />Colder than even Triton?????? Its a shame really not to have gotten a good IR spectra. <br />May help in determining if Sedna is from another solar system & captured by Sol.<br /><br />I agree with the five Earth mass rogue planet scenario. <br /><br />One problem I have, is that would it not accumulate enough hydrogen to devlop <br />into a gas giant over time, thus the original planet<br />just becomes a core???<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[h2ouniverse]

Well Uranus and Neptune are 20 Earth massed, and they are said to have some layers rich in very hot high pressure H2O (supercritical).<br />I would expect that there should be an intermediate value of the mass implying milder conditions for the H20 layer, so that the energy balance in absence of Solar power leads to open air liquid water oceans.

 

[3488]

Hi Joel,<br /><br />Very interesting idea indeed.<br /><br />Also with volcanic activity, assuming a youngish world, yes, these sunless worlds under<br />a super dense atmosphere may well have oceans of liquid water.<br /><br />Together with heat from volcanoes & the pressure of a dense hydrogen atmosphere to lower<br />the freezing point, yes, I think such planets do exist.<br /><br />An interesting field of study, once we do reach intersteller space.<br /><br />I am off to bed now, its late here.<br /><br />Good night everyone.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[h2ouniverse]

About detectability:<br />If Spitzer misses Sedna, that means it would miss a frigid Earth with similar temperature at about 700 AU or more, and a cold Jupiter at about 7000 AU+.<br />All hopes still permitted!<br /><br />Joel

 

[franontanaya]

So, what would be your preferred probe to explore those planemos? A New Horizons succesor? They'll try in fact to find new targets for NH after Pluto, that will be a nice testing ground. Voyager is 30 years older technology and it is still working, I wonder how long will NH be able to keep diving in the edges of our system.<br /><br />I doubt sails with so few experience would do any good then. Maybe an hybrid with some sail surface, nothing too spectacular, to help to save fuel for the meeting or travel later (with the fuel saved, not the sail) to other nearby KBOs. I think I remember they actually used the solar light push to help Pioneer or Voyager probes, and they sure do it with Earth satellites. As the dish points towards the inner Solar System, it's already catching some light.<br /><br />So, some of those bodies will be extrasolar undoubtablely, if they aren't hot and active anymore that may be like exploring frozen samples of past solar systems, specially if we have ways to look under their crusts of ice, like cryovolcanism. That sounds almost as good as going to other stars. <br /><br />So, about exploring extrasolar planets, I would say... bring 'em on! <div class="Discussion_UserSignature"> </div>

 

[qso1]

emperor_of_localgroup:<br />Another facet of space exploration I think you all are ignoring.<br /><br />Me:<br />I have mentioned a few times in different threads that telescope technology will play an important role in interstellar travel by first...giving us an interstellar destinaion worthy of human visitation. I don't think optical physics will allow us to see down to driveways on planets as far off as Alpha Centauri...but then I don't know for sure. I decided for my book that the best 22cnd C telescope will see is continents when viewing planets from light years away.<br /><br />However, if we see an earthlike world that is far more earthlike than mars, say within the next 50 years...and then spectral analysis strongly indicates life to be present...telescope tech will then be a pacesetter for interstellar unmanned, then manned craft.<br /><br />Telescope tech as you mentioned, is slow in progression but will almost certainly lead actual interstellar travel capability for some time to come. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[emperor_of_localgroup]

<font color="cyan"> I decided for my book that the best 22cnd C telescope will see is continents when viewing planets from light years away. </font><br /><br />Glad to see there are more people who also like to think ahead rather than sticking with the current available technology. My comment of 'seeing their driveways' is really light hearted exaggeration.<br /><br />You are right, optical technology wont be enough. It needs some technology that capture the light from distant stars/planets, then do amplication and processing to extract more info. It wont be in real time.<br /><br />Let us know about your book. <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[alokmohan]

Brown star sort of own dwarves stand out.They are trans star,largest candidate for dark matter. My hot favourite.

 

[3488]

I would not rule it out.<br /><br />Perhaps with large space based telescopes in formation, would act as a <br />single large one. We could do this right now, if the funding was there.<br /><br />I think 'seeing their driveways' is a bit of an exageration, but actually imaging <br />such planets, taking spectra, etc, cannot see why not.<br /><br />It is just time & the will to do it.<br /><br />Yes alokmohan, I think Brown Dwarves & rogue planets, rogue comets & rogue asteroids<br />are dark matter material.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[robnissen]

<font color="yellow">I think Brown Dwarves & rogue planets, rogue comets & rogue asteroids are dark matter material</font><br /><br />Yes, but. Dark Matter appears to be about 4 to 5 times more prevalent than known matter. AFAIK, there are NO theories that known objects such as Brown dwarfs, planets, etc., can make up more than a small percentage of known matter, let alone account for five times as much dark matter as known matter. Accordingly, while Brown Dwarfs, planets, etc., may account for a small percentage of dark matter, they cannot begin to solve the mystery of dark matter.

 

[h2ouniverse]

Hi FO,<br /><br />in reply to:<br />----------------------------<br /> wonder how long will NH be able to keep diving in the edges of our system. <br />------------------------------<br /><br />NH is travelling at about 3 AU / yr. So to reach a Classical Belt Object at 45 AU, you would have to add 5 years to the current 8-year mission, a total of 13 years. To reach an object at 75AU, a total of 28 years.<br />The cost of operations is higher and higher and is now a major criterion for the agencies in selection of missions. We need to find a way to reach 10 AU/yr if we want missions to Extended Belt to be selected by agencies. (to keep them within a 10-year duration).<br /><br />Not won...

 

[franontanaya]

Mmh, but NH can hibernate and be awakened whenever needed. As NH, their primary target could be a far Solar System object; Triton, for example. If we could chain the first probe devoted to Neptune with one or two Kuiper dwarves and, maybe, those Neptune trojans (that NH may investigate too in 2014), that would make for a great mission.<br /><br />We can only hope that hibernation technology gets better over time, and probes will be able to fly long distances with little -relative- costs. <div class="Discussion_UserSignature"> </div>

 

[dragon04]

<font color="yellow">Perhaps with large space based telescopes in formation, would act as a single large one. We could do this right now, if the funding was there.</font><br /><br />Remember the Space Inferometry Mission?<br /><br />IIt's still alive and kicking. Unfortunately, at best, the mission won't launch until 2015, it seems. <br /><br />And I'm inclined to agree that missions such as these, as well a larger integrated space based telescopes will provide the fuel for future manned space exploration. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[h2ouniverse]

It is true that they currently favor hibernation to cut costs. Btw, the less you operate a spacecraft, the less likely you trigger a failure...<br /><br />However, another factor is that science mission selection obeys the following rule:<br />* every science community shall have permanently enough data to process to sustain its size.<br />This means a mission that provides results 40 years later (10 years to decide and make the spacecraft, 30 years of travel) will receive no support from the science community. All 40+year old established scientists who may support it will be retired or dead when results are available: they will have to privilege missions that feed them with results, or risk lose their turn in the agencies' allotment.<br /><br />No sector can afford to be deprived of data for decades.<br /><br />Regards.<br />

 

[franontanaya]

There's this Neptune probe being studied (no budget yet) for the 2035:<br /><br />http://en.wikipedia.org/wiki/Neptune_Orbiter<br />http://solarsystem.nasa.gov/missions/profile.cfm?MCode=NTO<br /><br />That would include a Venus and Jupiter flyby. Once the budget for the Neptune mission is cut, they could hibernate and send that one, if we have got a good target for it. Anything they can stretch its design to allow deep hibernation and a KBO rendezvous won't hurt much, I hope. <div class="Discussion_UserSignature"> </div>

 

[h2ouniverse]

The very late date reflects what I've heard from JPL's members: they want to progress on penetration into gas giant's upper atmospheres before tempting aerocapture. <br />The point is that apart from Kronos into Saturn, there is no other such penetrator on the drawing board to my knowledge...