Interstellar Probes - Current Capabilities

[usn_skwerl]

we could build that 5 mile long mag-lev rail gun idea thats been kicked around for a few years, aim it up over the atlantic, get that whiz-banger going "ludicrous speed", or even "plaid," and send it on its merry way. realistically, in 10-15 years, with computer technology, we could probably get a bullet (with even somewhat respectable boosters - one or two 6-segment SRB's?) for the gun to launch the satellite out to the cosmos. for a payload weighing so little, the CG and center of pressure are aft, if not, throw a couple fins on.<br /><br />add on a slingshot from jupiter, maybe the sun, and fire up an ion drive once it gets towards the oort cloud, wave hello/goodbye as it passes voyager. <br /><br />sounds like a goofball idea, ill admit, but in my head, i could see a trip happening in a reasonable timeframe, even if the srb's arent even close to initial power of the gun--possible reincarnation for the STS TPS on the nose cap? i dunno, theres a lot of current potential to get something off on a fast trip. <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

Currently, interstellar travel at faster than light speeds is impossible. But this report by Zubrin and Speith suggests a solar sail driven craft could reach Alpha Centauri within 32 years using special light weight materials for the sails:<br /><br />Ultra-Thin Solar Sails for Interstellar Travel. <br />Phase I Final Report <br />December 1999 <br />http://www.niac.usra.edu/files/studies/final_report/333Christensen.pdf <br /><br />Too long for a round-trip manned mission but not for a unmanned scout mission. Note that the New Horizons mission just to Pluto itself will take 15 years.<br />If unmanned missions showed Alpha Centauri to contain habitable planets, then you can certainly imagine one way manned missions could take place.<br /><br /><br />Bob Clark <div class="Discussion_UserSignature"> </div>

 

[emperor_of_localgroup]

I don't know about you people, but sometimes I just laugh at NASA and now a few private companies and their tireless efforts to put a space craft at 8000 m/s speed. Because I have a growing vision someday this space traveling technology will face the same fate as horse and buggy did against automobiles. I dont know when and how the breakthrough will take place, but it is bound to happen. Until then lets travel the space on horse and buggy. <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[exoscientist]

Actually I think the Zubrin/Speith proposal is a near future one. What you need is <i>very</i> lightweight yet strong material for the sail. The single molecular layer material known as graphene might work:<br /><br />Radical fabric is one atom thick.<br /> Last Updated: Friday, 22 October, 2004, 13:18 GMT 14:18 UK <br />"A new class of material, which brings computer chips made from a single molecule a step closer, has been discovered by scientists."<br />http://news.bbc.co.uk/2/hi/science/nature/3944651.stm<br /><br /> Graphene has the same strength in two dimensional form that carbon nanotubes have in 1-dimension.<br /> However, if you read the Zubrin/Speith paper you see a problem with using very thin material is that part of the light energy just passes through, not imparting momemtum to the craft. That's the purpose of their calculation finding an optimum thickness for reflectivity and lightness.<br /> It might work to use just a few layers of the graphene sheets so that most of the light is reflected.<br /> Graphene so far has only been made in sizes a few microns across. Still this might be enough to test the feasibility of using this for solar sail material in lab tests.<br /> You might then just be able to tie very many of the micron size sheets together to get a solar sail of usable size.<br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[franontanaya]

We shouldn't be too greedy about time.<br /><br />If a system is cheap enough, we may "get" to a new star each century just by sending dozens of long-lasting devices. The first wait would be the only one long.<br /><br />But of course it would be dumb to expend too much effort in something that may become obsolete faster than it travels. <br /><br />Maybe the first interestellar probes should be designed so they could be always complementary to newer devices. A good dish could serve to transfer more data from newer probes with higher/better scientific payload.<br /><br />What would you put aboard an interestellar probe? <div class="Discussion_UserSignature"> </div>

 

[dragon04]

<font color="yellow">A propulsion module is a propulsion module.</font><br /><br />I wish. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[3488]

Hi FranOntanaya.<br /><br />Good point.<br /><br />One thing that still concerns me is the possibility of dangerous intersteller objects<br />like Rogues Planets, Rogue asteroids, Rogue comets, etc, that have been ejected from their <br />solar systems.<br /><br />True, space is vast & these objects will be seperated by huge distances, but they are still there.<br />An intersteller probe would need to be smart & be able to observe whats ahead,<br />using IMO IR detectors as most objects are detectable in IR as they are likely to be warmer<br />than the surrounding space.<br /><br />I do not think that this will always be impossible though.<br /><br />What to put aboard an intersteller probe?<br /><br />A very good question indeed.<br /><br />Certainly something like Cassini would be of immense value. It is dependent on the <br />mission objectives. Also chances are it would not be a single probe, probably a cluster probe.<br /><br />One element could be like SOHO, that observes the parent Sun 24/7, like SOHO<br />in orbit around Sirius, Procyon, etc, instead of our Sun.<br /><br />A Voyager / Galileo / Cassini / New Horizons type craft could be used to rendezvous with its <br />planets, etc.<br /><br />One element would certainly check out for the possibility of biological activity.<br /><br />Where would other posters like to see an intersteller probe go to?<br /><br />My current favourites (not in any particular order) would be.<br /><br />1). Alpha Centauri.<br />2). Sirius.<br />3). Procyon.<br />4). Epsilon Eridani.<br />5). Vega.<br />6). Delta Pavonis.<br />7). <a></a> <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>

 

[derekmcd]

Excellent point 3488. Certainly, the trip between stellar system would be clean sailing, but upon entering the system of your destination, the odds of impact would increase and be cause for concern.<br /><br />Having something akin to a FLIR (forward looking infrared) system with navigational capabilities would certainly help. I would be worried about the added weight and complexity to the probe, however.<br /><br />I like your idea of sending two probes traveling/communicating as a team. One with NAVFLIR and one dedicated to data collection. <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[vandivx]

"Maybe the first interestellar probes should be designed so they could be always complementary to newer devices. A good dish could serve to transfer more data from newer probes with higher/better scientific payload."<br />-----<br /><br />complementarity with new devices only works when there is no radical change in technology in which case it is hindrance, besides nobody can foretell what the future may bring, think about making horse buggies complementary to automobiles, it is much better to let the old technology die totally<br /><br />there is the problem that the data recieved from today launched probes received something like a century later will be problematic, we would need to build legacy devices then, like building a phonograph playing Edisons' cylinder records if you dug out somewhere such cylinders today and that is likely very tame example as changes in technology accelerate faster the more advanced it is<br /><br />I believe the taped recording of Pioneer probes to study that anomalous acceleration had to be read on legacy surviving machine and they were lucky to have it else it would be even more expensive data recovery than it was and we are only talking about some thirty odd years here<br /><br />any complementarity might be ok if we are heading into stale times as far as science progression goes regarding fundamental discoveries, sort of like scientic dark ages that could span a century or couple easily, that is not beyond my imagination<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[nrrusher]

<br />My current choice for a probe destination would be Centauri, but dependent upon what we can glean from telescope data. I wouldn't want to waste time going somewhere where there is not even an interesting planet or two to study/do a quick survey for possible future missions.<br /><br />Ideally, a single scout mission/fast flyby of, say Proxima, then Alpha, then Beta would be great. The probe would need to be equipped to map out each system and its planets, then use the star to throw it/gravity assist it on to the next Centauri system, thereby decreasing time to targets, saving fuel, and getting to see 3 systems in a relatively short period of time.<br /><br />If there was another system that the third star system/Beta Centauri could send it on to, even better.<br /><br />The keys would be longevity (obviously), durability, and a fairly good mapping system that could get a full layout of the planetary system and even some pretty good environmental data on each planetary body fairly quickly. Hopefully the probe will be moving pretty fast and may not have much time to do a survey.<br /><br />NR

 

[MeteorWayne]

Where is the power going to come from for a mission that long?<br /><br />Just have to wonder. <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>

 

[nrrusher]

<br />Obviously the key question is exactly how long.... Depending on how fast we are able to send it will affect the amount of power required. However, nuclear power would be almost certain to be included in some fashion, at present anyway. More than one reactor at that, with a couple of them on standby I suppose.<br /><br />But, that is a moot point until we know how long of trip it will be.....whether it is 75 or 50 or 100 years would make a big difference.<br /><br />NR

 

[MeteorWayne]

There is no stanby for the current nuclear power generators.<br />They convert the heat of radiactive decay into electricity, and that output depends on the half life of the plutonium involved.<br /><br />A true nuclear reator might be able to output power longer, but then you are talking something massive, that we cannot currently accelerate anywhere near even 0.1 c. <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>

 

[nrrusher]

<br />What is the current half-lifes available??<br /><br />NR

 

[nrrusher]

<br />Where To?? I would say just start from the closest ones and work your way down the list. A standard probe, mass produced (10 or more or so) would get cheaper as each one is built, and we could get them out the door a lot quicker. <br /><br />The mission should consist of several of them, not just one Centauri mission. Heck, let's just create a completely separate/new Agency, the "National Interstellar Research Association" NIRA to handle this one. A streamlined agency that has one responsibility...managing interstellar probe based research.....

 

[MeteorWayne]

And who's paying for the new agency? <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>

 

[alokmohan]

Dont you feel the idea is absurd till now?

 

[3488]

Its a great idea nrrusher, but as MeteorWayne syas, who will fund it?<br /><br />It will require its own budgets, etc, in other words a complete new agency in itself.<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>

 

[franontanaya]

Mmh, if time wasn't the issue, would it be possible to make the collected data to return physically to the Solar System?<br /><br />The probe wouldn't carry any big dish, or an high power system, just something good enough to charge a battery during the fly-by and power a few sensors and the sail navigation system once each while. Maybe cheap enough to afford a bunch of them and counter an high loss ratio.<br /><br />The released solar sail could slow down the probe, which would gather the data, then it would drop all scientific instruments, throw away any thrusters and tanks, and sail back the data storage. The returning pack would be really small and could be better shielded so it can get closer to the star to gain speed; then, if it could be intercepted, it would return a lot more data than a dish 4 light years afar I guess... <div class="Discussion_UserSignature"> </div>

 

[robnissen]

<font color="yellow">The released solar sail could slow down the probe, . . .it can get closer to the star to gain speed.</font><br /><br />Numerous problems. <br /><br />1.It takes as much enery to slow down a probe going at .1c to zero, as it took to take it from 0 to .1c. As discussed previously, a solar sail can not increase much in speed after the orbit of Saturn, and by Saturn a solar sail cannot get to .01c (probably not .001c) let alone .1c. I had suggested possible lasers to continue to accellerate the solar sail after Saturn, but as pointed out above, that has its own problems that must be solved. But even if we could use lasers to accelerate to .1c, there are no lasers to point at the solar sail at A.C. to slow the prob back down. And putting the solar sail in front of the ship would only slightly slow it down, because, as stated above, a solar sail can only be used to accelerate (which by definition also means decelerate) a ship for about ten AUs. The ONLY possible method we have for reaching A.C. with anywhere close to our current technology would be for a fly-by mission. We have NOTHING currently that could slow down the probe at A.C. <br /><br />2. Even if we could stop the ship at AC, There is currently no technology to use a gravity assist to get anywhere near .001c, let alone .1c.<br /><br />3. Finally, as stated above, there is a HUGE issue with protecting the ship from dust grains. There is no reason to worry about forward looking navigation to see asteroids, planets and other large objects because an uprotected ship traveling at .1c would long since have been destroyed by dust grains. Hubble and the ISS have nice big pits from dust grains hitting the ship at 30 km/s. Multiply that by a factor of 1000 to 30,000 km/s and the Hubble and ISS would be rubble, if not vaporized. That is what will happen to any ship going .1c that is not somehow shielded from dust grains.<br />

 

[3488]

This is clearly something that is fraught with many dangers.<br /><br />I would love to see an intersteller probe happen though, but I fear that time is not our <br />friend regarding the distances involved & speeds that are practical.<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>

 

[nrrusher]

<br />yes, right on all counts. Funding would be for a new agency. In other words, instead of giving the $ to NASA, appropriate it for the new agency.....I am just thinking out loud here, but I see the interstellar probe business being different enough from NASA's standard fare, certainly from an operational point of view, that it would make sense to create a different agency that didn't have the overhead and would look at the project from a more focused perspective.<br /><br />On the speed side, .1c would be touchy, but everything I have come across seems to lean toward the idea that, while it would need consideration, the risks could be mitigated. As you increase past .1c though, the danger increases quite a bit, to where at .5c avoiding ANY collision at all becomes necessary.<br /><br />In any case, how little we know about the interstellar medium and what is in it, would say the risk is worth it. At worst, so we get a few years or less of good data on the interstellar environment before the probe swiss cheeses itself to death. <br /><br />NR

 

[franontanaya]

The .1c is kinda arbitrary. I don't think in 500 years we will have visited so many stars that we would go back to the first one and outrun an old probe. The Centauri system doesn't seem the most exciting place out there anyway, good enough for the first test.<br /><br />That would be a purposeful interestellar probe, even if the real chance to get there is too small and requires 500 years.<br /><br />Anyway, is there a physical limit to how many solar sails we could attach together to catch more wind? <br /><br />And another question: would the sails themselves (a lot of them tied together) be useful to return data? I mean, if they were 4 l.y. away, would they be able to reflect enough light so they could be tracked from our Solar System and measure the gravity pull of invisible planets? <div class="Discussion_UserSignature"> </div>

 

[h2ouniverse]

As far as the target is concerned:<br /><br />I hope we will quite soon discover big planemos closer than 100000 AU (with tidal-heated moons). <br />After all, even a Jupiter-sized cool planet would be still be undetected today, beyond 2500 AU. (visible spectrum magnitude />24).<br /><br />Best regards.<br />

 

[tdamskov]

Do we have reliable information on the density/amount/size of interstellar dust grains? How much dust would this probe encounter on a multi-light year cruise? If a dust grain hits the solar sail (assuming the sail is only a few nm thick) I suspect that most grains would simply drill straight through the sail. A huge number of impacts would be needed to have any measurable effect.<br /><br />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.<br /><br />On the other hand there's the probe itself. One would have to decide what size grains one could reasonably protect against or avoid. During the interstellar cruise stage, deploying multiple foldable layers of very light materials (perhaps the solar sail material itself?) in front of the craft might be a solution against the smallest and most numerous grains and particles. The trick is to present many surfaces capable of deflecting and dissipating the energy of incoming grains in stages. This "clothball" approach reduces the amount of protection needed on the leading edges of the craft. The same multi-layer principle is used to protect the ISS.<br />