[X] My Assistant

[marsbug]

There seems to be no shortage of ideas and enthusiasm out there, just a shortage of suitable energy sources.
Perhaps minaturization will progress to the point where an interstellar payload would be small enough that such fearsome fuel requirements wont be needed. Could a a 1kg or less (payload mass) mission ever be practical?

[Bob Shaw]

There seems to be no shortage of ideas and enthusiasm out there, just a shortage of suitable energy sources.
Perhaps minaturization will progress to the point where an interstellar payload would be small enough that such fearsome fuel requirements wont be needed. Could a a 1kg or less (payload mass) mission ever be practical?

Sending a lot of tiny probes packed with self-replicating technology and designed to return the important stuff - information - may well be the way to go. Think of it as the race between sperm to fertilise an egg - millions fail, but one gets there in the end, with a result with which we are all familiar...


Bob Shaw

[tasp]

After the acceleration phase, one could simply fly through space with the pusher plate forward . . .

{Yeah, I read the Dyson book}

[helvick]

Sending a lot of tiny probes packed with self-replicating technology and designed to return the important stuff

I find the "school of starwhisps" image quite endearing but I can't see anything that's being suggested here being even remotely possible.

For me the the best approach remains taking a very long term view and firing out some really slow things designed to function for 100's of years just in case we never figure out any way to go fast efficiently and reliably.

[edstrick]

It's abundantly clear from engineering concept studies (like the BIS Daedalus Project) that interstellar travel is possible. It's also clear that the level of effort required pretty much requires the resources of a space-based industrial civilization. Without some low plausibility engineering/physics breakthrough, it's beyond any but the maximum coordinated effort of a global planetary civilization.

[djellison]

Several SETI related posts delete ( there is a thread for SETI discussion - but it is not encouraged - read the rules )

Further posts regarding time capsules and historical references also deleted. Certainly OT and virging on the political.

Thread moved from Voyager/Pioneer into an appropriate sub-forum.

Doug

[marsbug]

also your bad to quote the whole of the preceeding post....read the rules on that one as well - doug

Sorry- my bad!

[Guest_Myran_*]

Some nice ideas have been presented here, but dividing a probe into several miniature ones doesnt solve one of the most important problems. And that is communication back to Earth.
Would those 'starwhisps' by some magical trick somehow pull a terrawatt laser and nuclear reactor our of their sleeve?
(Yes the sail items might be modified to work as one dish for radio also, but again, that would add quite to the complexity of the sail and the number of things it should be able to do. Then the power needed for transmission would not be that much smaller and complex radio signals carrying megabytes of data will degrade more than laser in the interaction with gas, the stellar wind, galactic magnetic field etc etc.)

Another misunderstanding with lightsails is that they're unable to break their speed. They actually are!

One way would be to use the laser light itself and change to the opposite tack, so that the 'mirror' surface directs the laser light forward.
(Anyone who knows a bit of sailing here? Its more or less the same thing as when you arrange the sails of a ship to go against the wind.)

Its not as efficient as the acceleration but if you could charge the sail with quite a lot of electricity it would generate its own magnetic field and choosing the polarity the sail would be able to break. If the heliosphere around that star are as extensive as for Sol it could break for almost a lightyear in this fashion.

Last and most risky would be to go very near the destination star breaking both by the light and stellar wind.

One insterstellar probe might use not only one but two or all of these methods to either break enough to get a decent observation time at the target star or even come to a stop and so be able to explore interesting worlds one by one at closer range.

[marsbug]

Some nice ideas have been presented here, but dividing a probe into several miniature ones doesnt solve one of the most important problems. And that is communication back to Earth.
Would those 'starwhisps' by some magical trick somehow pull a terrawatt laser and nuclear reactor our of their sleeve?

I would guess that this is where the self replicating probe idea comes into its own, as a probe that could build a copy of itself could build a reactor and transmitter on site as well- if it could find suitable resorces.

[Bob Shaw]

The big problem with 'tiny' probes is the relationship between surface area and mass. It's ideal for light-sailing vehicles, but you'll end up printing the payload onto the sail to get anywhere. In one sense, that's not such an issue - if you build your spacecraft the same way as you build CPUs in computers then you can do a helluva lot in a tiny space, and then distribute the processing/sensors etc so that things are reasonably failsafe. You could even tack against the laser light from earth by using the same sort of technology as is found in LCD projectors, with nanomechanisms which tilt as required. All these are barely beyond the state of the art. It's when you try to manipulate dumb matter, however, that things get difficult - or at the very least, expensive.


Bob Shaw

[edstrick]

The other problem with tiny probes are diffraction limits and photon count limits. Diffraction limits what they can see and do, looking around, and transmitting a narrow angle data beam back to earth/solar-system. Photon count limits what you can see without a light bucket above the noise level of your detectors.

The BIS Daedalus payload, at least as a straw-man idea, consisted of a hubble class telescope. It would get orbits on planets and larger asteroids in a system as it approached with enough time to pick a "best" fly-through trajectory, then be able to do hubble class imaging and spectroscopy on all planets during the pass.

[nprev]

Sure would be nice to figure out a way to stay awhile in the system, though.

If the mission had suitably equipped flyby/orbiter-class sub-probes (programmed in advance by some pretty smart AI on the part of the main vehicle computers), they might be able to stay in the system via a combination of direct thrust (assuming that the carrier vehicle can decelerate enough while entering the system before releasing them) and sub-combinations of aerobraking through the atmosphere(s) of gas giants & subsequent gravity assists to reach targets of interest.

If something like TPF or better could survey the target system in sufficient detail beforehand, this might yield enough data to plot such a mission.. it's still a pretty risky & by no means manifestly feasible approach. And, as Myran pointed out, returning data at all would require at least that the carrier vehicle was equipped with a monster laser, and that the subs would be capable of sending data to it as it recedes @ some huge velocity, given the fact that it might take them years to reach their final targets.

Wild thought: How about hyper-aerobraking the carrier ship through the atmosphere of a hot Jupiter? (Additional assumptions: extraordinarily temperature-resistant materials and spacecraft components capable of withstanding perhaps a few million Gs). Idea here is to shed just enough speed at this point (right near inbound trajectory perihelion, which is good) after powered braking to get below the star's escape velocity, then release the subprobes to do their respective things. This way the carrier with its megalaser stays relatively nearby to act as a comm relay while the subprobes conduct their missions.

[djellison]

Twice this thread has entered tin-foil hat ground. Twice I've recieved complaints. It is now closed.