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Comment by palmotea | Hacker News Reader

> It is stated multiple times across the article...

I was a bit confused by your comment, but I think the article you're referring to is not the OP, but the article the OP was commenting on: https://www.cell.com/iscience/fulltext/S2589-0042(25)01403-8...

> Does anyone have an idea how to equip a 1g spacecraft with any means to steer itself at 1/3 speed of light? The kinetic energy at that speed would seem to require something very incompatible with the weight constraint, to my understanding.

I'm also wondering how such a thing is supposed to communicate back to us over dozens of light years. That also seems incompatible with the weight constraint.

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>I'm also wondering how such a thing is supposed to communicate back to us over dozens of light years.

Just spit-balling here. Send out the first batch of probes and then 5 years later send another batch of probes. The first batch of probes does their surveying for 5 years, when the later batch of probes start arriving. The data is uploaded to the late-comers, who aren't on an intercept course. Instead they are on a trajectory that causes them to swing around the black hole, and head on back to earth with the data.

> Send out the first batch of probes and then 5 years later send another batch of probes.

What's the separation there, at 0.33 lightspeed? 1.65 light years? Wikipedia says Voyager is 168.35 AU away, and Google says that's 0.00266 light years. Voyager has 23-watt radio focused by a 3.7m dish and its signals are received by a 70-meter dish on Earth.

So you're talking about a 1g spacecraft signaling another 1g spacecraft over 620 times the distance to Voyager, without any of the beefy equipment that exists on both ends of the Voyager link.

Hmm. Seems like you are you multiplying 5 years by 33% of light speed to come up with 1.65 light years? I apparently didn't explain well enough. The 5 years is for the first batch of probes to gather data over an extended period of time (while in orbit around the black hole). The second set of probes is just a roundtrip "fly-by" to collect the data from the first probes and return it to earth. No reason that the return trip probes would have to be very far from the data gathering probes. Maybe you can't orbit close enough to the black hole at these speeds without getting too close to the accretion disk?

Even then, I think you're going to have massive distances between tiny probes moving very fast relative to each other. Maybe not 1.65 light years, but communication over Voyager's 0.00266 light years or even a much smaller distance (e.g. Earth to moon) seems insurmountable for two 1g probes.

Also, the probes are in deep space, right? No solar power. Where are they going to get the energy?

https://en.wikipedia.org/wiki/Betavoltaic_device ?

So skip the communication, and just have the one probe do the gravity assist to get headed back to earth with the data it collected.

The launch system isn't consumed by launch, so launch them as often as necessary to keep the communications gap as small as needed.

Not like a 1 gram probe is going to be expensive compared to the launch system.

>I'm also wondering how such a thing is supposed to communicate back to us over dozens of light years.

Split particle pairs. We just need to repeal the no cloning theorem, maybe if we promise to not use it for FTL communication the legislators would go for it.

We could call them "Sophons" while we're at it.

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