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Kal-El_Skywalker1998 t1_jd72h8b wrote

There's talks of creating a long-range probe that could travel as fast as 1/4 the speed of light, which would make it capable of reaching Alpha Centauri in only 16 years, with a round trip taking only 32 years plus however long the probe is actually in the Alpha Centauri system collecting data.

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3SquirrelsinaCoat t1_jd7jwbe wrote

The light sail carrying a wafer-thin sensor package is not meant to come back. One of the biggest challenges is figuring out how to slow it down as it approaches AC. What will most likely happen is the probe just zips through the system, grabs whatever data it can, and sends it back to Earth before flying on into nothingness. The alternative - slowing it down, redirecting it back toward Earth with orbital maneuvers, speeding it back up, and then having it actually reach us (not just zip through our system) - technically, we're not even close to that as a spacefaring species.

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magnabosco t1_jd7s4v9 wrote

If you sent several in a chain, the probes could transfer the data back to each other, eventually coming back to earth, no?

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3SquirrelsinaCoat t1_jd7uak6 wrote

Sending data back is the point, and I don't think you need a chain to accomplish that - just make sure the antenna is pointed in the right direction. The person above me seemed to suggest that the probe itself will be brought back, and that's not so. But the data, definitely.

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Representative_Pop_8 t1_jd7wmdp wrote

I think the plan is to send a chain, reason is that the v prices would be too small to power any type of transmitter that could reliably reach earth, so you use the train to relay. also redundancy since space v dust could damage some probes

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valetofficial t1_jdaby07 wrote

You might as well just make von Neumann probes at that point.

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Representative_Pop_8 t1_jd7wa2b wrote

which project, I only heard the one with the microprobes powered by sails, starshot I think that was called. but that was one way as far as I recall, since you need a laser to power them, which you won't have at destination for the return trip

I don't see how we could do round trip with any type of technology we can design for at least several centuries.

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likmbch t1_jd97uur wrote

Can you fucking IMAGINE? Having a human made spacecraft in another SOLAR SYSTEM?! Even if the data we got back weren’t images of the planets there and just basic data, that would be so incredible.

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xNaquada t1_jdahwqu wrote

I'm not debating that it would be incredible data, but if we're doing a 16 year journey where data is coming back, then it would be absolutely foolish to not get images -- New Horizons showed us so much of Pluto, and that was early 2000's tech. We're 2 decades ahead of that now.

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likmbch t1_jdaidtq wrote

Yeah…. But… you know Alpha Centauri is a LOT farther, right?

It’s about 6900 times farther to Alpha Centauri than to Pluto.

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xNaquada t1_jdak21a wrote

Yes, of course. What is your point?

We're commenting in a chain of a theoretical probe that doesn't exist and imagining how awesome it would be.

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likmbch t1_jdal70y wrote

Because you brought up how long ago new horizons was as if that is some indicator of our ability to transmit images back from Alpha Centauri.

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xNaquada t1_jdalrci wrote

I brought it up as an indicator of what the images of Pluto looked like with 200x era tech (quite good). So imagine what we could get even now (+16years+signal back time).

>Even if the data we got back weren’t images of the planets there and just basic data, that would be so incredible.

It had nothing to do with the ability -- given we're talking about a theoretical probe that will transmit data back, I had made the same assumption as you did (context of the reply) in that data would indeed come back.

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likmbch t1_jdam2m9 wrote

Why would you send a probe without a data stream coming back?

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xNaquada t1_jdao0x8 wrote

Why would you ask if someone didn't know that a different star is a lot farther than an object in our solar system?

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likmbch t1_jdao9dv wrote

Because you are saying stupid things. Didn’t want to assume

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xNaquada t1_jdapxjx wrote

😂 I think you're just mad because you couldn't be smug and decided to immaturely lash out.

Find your way off the internet before you waste more time manufacturing friction where none existed.

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likmbch t1_jdaqy38 wrote

Huh, I’ve never met a smug person before.

And I imagine you like manufacturing friction when you’re home alone every night.

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starhoppers t1_jd7fkye wrote

Why would it need to be a round trip?

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halfanothersdozen t1_jd7o6oi wrote

It would basically be impossible to receive radio signals from a probe that far away. If you want the data it would have to come back

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starhoppers t1_jd7p0bh wrote

Problem is, during that 32 years we’d probably develop faster propulsion!

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danielravennest t1_jd8w8wh wrote

It's hard to beat a laser-pushed lightsail going 1/8th the speed of light. The downside is the spacecraft will be tiny.

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UnknownStrikex t1_jd80y0n wrote

As much as I'd like to see a mission to Alpha Centauri that would only take 2-3 decades, there are a few significant hurdles that we are going to have to jump over. So far, the 2 main types of proposed methods of interstellar travel have been a "slow" nuclear powered ship that cruises between 0.04-0.12c and a "fast" nano-probe powered by a light sail that can reach 0.10-0.20c.

Project Daedalus was originally conceived in the 1970s as a fusion rocket that ran on deuterium/helium-3 that could travel to Barnard's star at 0.122c. The main drawback is that the amount of Helium 3 required would take roughly 20 years to mine, and the probe would not have any leftover fuel to de accelerate and would instead be a flyby mission. Due to the scarcity of helium-3 and the inability to go into orbit around any potential planets, a probe of Daedalus' design is unlikely to be viable.

Icarus Firefly was designed in 2009 and utilizes a Z-pinch fusion engine running on deuterium/deuterium, which resolves the issue of needing copious amounts of helium-3. However, it would have a maximum cruise velocity of 0.045c, and the after accounting for acceleration/de-acceleration, Firefly would arrive at Alpha Centauri roughly 100 years after it has been launched. I see this as a more viable option than Daedalus, but constructing such a probe in orbit and ensuring that it can operate for 100+ years without fail would be challenging.

Finally, we have Breakthrough Starshot, which is perhaps the most achievable out of the 3. These gram sized probes could reach Alpha Centauri in just 20-40 years, but they would be restricted to fly-bys only and need to be powered by a 100 gigawatt laser array located in space. In order to send such a mission, we would need to effectively scale down sensors, chips, etc to meet the stringent weight limits and then find a way to set up an orbital laser array. Not impossible, but still extremely difficult.

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danielravennest t1_jd8xys1 wrote

Yet another method is using the Sun both as a power source, and a gravitational lens to focus the beam on a ship in transit. Starshot is limited by the laser array size. The probe quickly gets too far to maintain beam focus.

So instead you build your laser array near the Sun, where power is plentiful. To start with you aim the beam directly at the vehicle. When it gets too far you switch to a relay mirror at ~800 AU. The Sun bends light by its gravity. In this case it makes a lens with a 2 million km diameter, which gives you astounding resolution.

The beam is used by the ship to power a particle accelerator. The first part of the trip the accelerator is pointed aft to speed up. Later it points the other way to slow down. Going the other way, your communications will be focused back to the relay mirror, so you can get data back.

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