How do you think we can get to Proxima b?
How do you think we can get to Proxima b?
(OP)
Soo.. the other day I read that the Alpha Centauri system might have several exoplanets apart from Proxima b.. so I looked for info about the Starshot project and found out that the team launched in July a 3.5 x 3.5cm satellite weighing 4 grams.. this encourages me to believe that the project can actually be achievable.. what do you guys think? do you think that a faster interstellar travel system will be developed even sooner?
I decided to make a video on this exciting topic and I would like to share it with you guys: https://youtu.be/jF2juqeDa-E
I honestly can't wait 44 years for receiving the first images of Proxima b, I would be 70 years old. There must be another way of getting there sooner.
I decided to make a video on this exciting topic and I would like to share it with you guys: https://youtu.be/jF2juqeDa-E
I honestly can't wait 44 years for receiving the first images of Proxima b, I would be 70 years old. There must be another way of getting there sooner.





RE: How do you think we can get to Proxima b?
another day in paradise, or is paradise one day closer ?
RE: How do you think we can get to Proxima b?
But, these aliens were extremely long-lived, and had a massive sail.
Note, however, one fundamental thing that most people seem to be missing is the divergence of the beam. A 5-m aperture at 1064nm produces an Airy diameter of 0.5 microradians. A 10-km diameter sail becomes smaller than the Airy diameter at a measly 2-millionth of a light year, which gets you to about 1/3rd of the way to Mars' orbit. And, that means that at 1 ly, only 3.25E-12 of your transmitted energy will reach the sail, even with perfect pointing.
As for getting any signals back, I think the shot noise of any of the Centauri stars would swamp the radio signal from a probe. Now, if the probe could build itself a fusion reactor, once it gets there, THAT might be promising.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
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RE: How do you think we can get to Proxima b?
Proxima b is 4.2 light years away (1533 light-days). OK, lets say we're going to have the current Voyager 1 type of capability at that distance. At the moment, Voyager 1 is slightly over 19.5 light hours away using a 3.7 meter diameter antenna with a 22.4 watt transmitter sending data at about 160 bits-per-second. We can still communicate with it using multiple antennas on earth. Granted, Voyager 1 is older technology, but the physics remain the same, and to receive Voyager we are using the latest receiver and antenna methods we have. Granted, a newer, fancier modulation method might improve the link by 6 dB (factor of 2) But instead, lets be generous, and just round that distance up to 1 light-day away. The power relationship one-way is 1/r^2 .
So, to get 160 bps of data from a probe with a 3.7 meter antenna at the distance of Proxima b you need to transmit with a power of of a little over 52 Mega-watts.
RE: How do you think we can get to Proxima b?
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: How do you think we can get to Proxima b?
another day in paradise, or is paradise one day closer ?
RE: How do you think we can get to Proxima b?
The return signal is difficult and the Breakthrough website doesn't offer any details how that could be accomplished.
Latest sci-fi treatment of interstellar travel: Kim Stanley Robinson, Aurora (Tau Ceti in that story IIRC). As with all KSR stories, the technology of the spacecraft is thoroughly explored. He gave them fusion reactors and 3d printers that could replicate organic material to keep the crew alive.
A much more accessible, though still very difficult, target would be to accelerate a probe (Deep-Space-1 style ion thruster) to intercept an extrasolar asteroid as it passes through the solar system, like this one:
https://www.space.com/38580-interstellar-object-sp...
About 1/1000 the speed would be required to intercept, and telemetry sent back before it passes the orbit of Saturn, say, 10 years from now. That would get some alien material to study from another solar system "without leaving home".
STF
RE: How do you think we can get to Proxima b?
http://www.lunarsail.com/LightSail/rit-1.pdf
RE: How do you think we can get to Proxima b?
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.
RE: How do you think we can get to Proxima b?
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: How do you think we can get to Proxima b?
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.
RE: How do you think we can get to Proxima b?
It'd probably make more sense to use the asteroid, or whatever, for a gravity assist manoeuvre ... many orbits gradually building speed. The advantage of this is you don't need a tiny satellite ... a heavier satellite would need more orbits. But this would be limited to a small fraction of c. The intention of the light sail is to use laser energy to accelerate a tiny mass.
another day in paradise, or is paradise one day closer ?
RE: How do you think we can get to Proxima b?
I'll be honest the idea of a spacecraft being able to survive this is almost laughable, but we could control the impact to some extent. Using thrusters to reduce the relative velocity between the spacecraft and asteroid. Choosing an asteroid with a lower initial velocity. Increasing the elastic stretch of the collision to reduce the acceleration of the spacecraft, though whatever part contacts the asteroid can't avoid the full speed of impact.
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.
RE: How do you think we can get to Proxima b?
Something that'd "help" would be if you left some of the satellite mass on the asteroid, so the rebound momentum was associated with a smaller mass than the impact, increasing the rebound velocity.
But, as you agree, the idea doesn't sound very practical.
another day in paradise, or is paradise one day closer ?
RE: How do you think we can get to Proxima b?
Funny. Earth's orbital velocity is 30 km/sec, how come that's not enough?
Oh right, the probe loses speed as it climbs the gravity well. Comparing Voyager velocities at 90 AU distance to asteroid velocity at 2-3 AU is...well, not correct.
Gravity assists can give all (or a large part of) the orbital velocity of the larger body to the smaller, in a perfectly elastic fashion. Almost as importantly, you change the vector of the velocity (angle) for the probe without expending any (or at least a tiny amount of) fuel to do so, if you do it right.
Which makes me wonder, could global warming be caused by the shift in earth's orbital radius due to gravity assist maneuvers by orbital probes? Hmm.
RE: How do you think we can get to Proxima b?
another day in paradise, or is paradise one day closer ?
RE: How do you think we can get to Proxima b?
RE: How do you think we can get to Proxima b?
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.
RE: How do you think we can get to Proxima b?
What about an across-the-sun sling-shot towards alpha Centauri B trajectory?
during a timed launch widow...
Launch toward the moon with a free-return trajectory. During the return to earth, accelerate with a long thrust burn for an Earth-gravity assist into an almost direct shot [steep diving trajectory] at the sun for sun-grazing gravity assisted acceleration and turn-towards alpha Centauri system trajectory [path]? very high departure velocity can be anticipated. NOTE: this would mimic the path of an interstellar asteroid just discovered racing past the sun with a non-return trajectory at exceptionally high speeds and shallow trajectory turn.
This path would require...
substantial shielding/insulation/radiation protection from the sun.... beneficial for interstellar coasting and protection from the 3-stars of Alpha Centauri at the other end. NOTE: cleverly integrated, this shield might also work as a directional high-gain antenna and as a solar-energy collector/storage-cell.
A booster for the initial high acceleration from the moon toward the earth is needed.
A propulsion system for in-solar-system acceleration and course corrections is needed.
A substantial service module [bus] that includes an ion propulsion system for interstellar course corrections, stabilization and [ultimately]deceleration at destination. Jettison-able fuel tanks and/or very light fuel bladders would be necessary.
Not to mention all spacecraft design elements... structures, systems, avionics/computing-AI/instrumentations/antennas/communications/optics, TNG/electrical power, thermal control elements and insulation [including micrometeorite protection], etc... for long-duration 'interstellar flight' to Alpha C system.
OH yeah... and while the spacecraft is coasting... develop an expansive network of radio astronomy/comm spacecraft... distributed solar-system wide aimed directly towards alpha C and/or the spacecraft's trajectory... continuously listening-for the 'lonely bird' running from home.
Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
RE: How do you think we can get to Proxima b?
The process of releasing these units can also involve a momentum transfer to aid the deceleration of the main ship.
STF
RE: How do you think we can get to Proxima b?
Somewhere I read that the best way for the probe to communicate would not be radio, but laser. I seem to recall from the article that about 200,000 watts would be required from a very well focused beam at several light years distance. NASA will soon demonstrate laser communication from Mars that will allow 1 to 10 Mbps data rate - 10 to 100 times what is available with radio. https://www.nasa.gov/mission_pages/tdm/lcrd/index....