Question Mission to Alpha Centauri

[statisticsnerd]

I read in an article recently that it would take 50,000 years for a to reach Alpha Centauri using current technology.

Obviously the probe would run out of power a long time before then with a full battery of scientific instruments active (I believe the Voyager probes have a decade or so left until they go cold and they were launched in the 70s). The Voyager probes still draw a few hundred watts, but as soon as it goes below a certain level they will be defunct.

That got me thinking.. what if the probe could be designed so that it uses RTGs but the ONLY device drawing power is a timer and everything else stays asleep until the clock hits ~50,000 years into the future (whenever it is expected to arrive at Alpha Centauri), and then all of the instruments "wake up" and start transmitting data back to Earth. The timer would have to be designed to draw just a few milliwatts, and several of these probes should be sent for redundancy purposes in case some of them malfunction during the long journey.

Thoughts?

 

[Keatah]

It doesn't really matter how much power you draw from an RTG, they have a set lifetime and that is it. They are not like batteries. Sure there's some degradation of the thermocouple, but that is not the limiting factor.

[ame="http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator"]Radioisotope thermoelectric generator - Wikipedia, the free encyclopedia[/ame]
[ame="http://en.wikipedia.org/wiki/Radioactive_decay"]Radioactive decay - Wikipedia, the free encyclopedia[/ame]

Furthermore, any probe launched now or in the near future will most certainly be eclipsed by something a 100 years later. So let's just do it when we're ready. And that, as much as everyone doesn't like hearing it, means when we can build StarTrek-like ships. Or at least get some good materials and propulsion technologies going.

---------- Post added at 01:38 AM ---------- Previous post was at 01:31 AM ----------

Additionally, it would only make sense to build a probe that can make it there BEFORE any advancements in tech allow a faster probe to catch up and race ahead of it. There is going to be a sweet/efficiency spot someplace. I do not know where that is.

But I can tell you that what we do today will be overshadowed by what we do in 20 years. This 20 year period is "invalid" for a launch window, because it is economically feasible to wait these 20 years and go with the faster tech.

Now, perhaps in 30 years we get a super-duper warp drive and can get there in 2 years. Then it makes sense, once a breakthrough is made, another breakthrough to shorten those 2 years to, say, 3 weeks is not likely to happen. So that is a valid time window.

Simply put, as long as we are "at risk" of coming up with something better, it's best to wait for that better thing. Once we are sure we won't develop something, then, and only then is it time to consider a long journey.

 

[T.Neo]

50 000 years is with the kind of probes we currently field. You may be able to get a transit time a good deal shorter than 50 000 years with technology that we could currently develop, but do not yet possess. Such a transit time would likely still be pretty impractical though.

 

[garyw]

Even with current tech the trip time can be reduced to about 1,000 years but the cost is enormous and there are many things it's better to have in place first such as a probe at the suns gravitational focus to allow better imaging of exo-planets.

I think the big worry is when you look at probes like hayabusa and gallileo. When an interstellar probe fires up it's engines it needs to be able to fix itself and we are some years away from that level of AI and self repair capability. Until then I can't see anything going much further than the voyagers have.

I look forward to seeing how new horizons does when it's past pluto. Because of it's speed it's certainly an interesting precursor to an interstellar probe.

 

[Urwumpe]

Well, but we also made some big leaps already in automatization in space. Cassini can for example navigate mostly without Earth tracking station data, a big improvement to the previous generation (But at a price in mass).

I am pretty sure, it would be possible with currently available technology to build a probe that could be "thrown" into an unknown solar system and still be capable of mapping and navigating it, as long as the propulsion system has the propellant for it.

Would maybe make a nice Orbiter challenge... testing probe AI algorithms in unknown solar systems. But how many people would participate there?

 

[garyw]

I am pretty sure, it would be possible with currently available technology to build a probe that could be "thrown" into an unknown solar system and still be capable of mapping and navigating it, as long as the propulsion system has the propellant for it.

Isn't that just a standard star tracker algorithm? If a probe can identify several guide stars it can easily orient itself and I know that Pulsar navigation is considered a key technology for interstellar flight.

 

[Cosmic Penguin]

If you are interested in reading up the challenges and potential design features of an interstellar exploration probe, look up Centauri Dreams: Imagining and Planning Interstellar Exploration by Paul Gilster.

 

[garyw]

I already have a copy of that book and I've been following the blog with some interest over the last few years. Its where my pulsar navigation link goes and it's certainly a blog well worth reading for anyone interesting in the challenges of interstellar missions

 

[Urwumpe]

Damn, I already had my Amazon order for this month ordered...

Garyw: It is a bit more than just Star Tracking, since Star Trackers still have many assumptions on the vehicle position, starfield matching is the better term there. Also you would need Planet tracking, software capable of basic astronomy, etc.

 

[sorindafabico]

[ame="http://en.wikipedia.org/wiki/Project_Longshot"]Project Longshot - Wikipedia, the free encyclopedia[/ame]

http://en.wikisource.org/wiki/Project_Longshot