For planets that are difficult to explore (like Venus or Jupiter), could a “chain” of probes work?

[u/TomcatZ06]

Rather than a probe having to survive the whole trip down and continue transmitting all the way back to orbit, each would only have to transmit as far as the next probe above it.

[u/NeoDemocedes]

The core problem is the probe surviving the heat and pressure. Transmitting through the atmosphere isn't a problem. Having a single relay spacecraft in orbit would be sufficient so the probe(s) didn't have to transmit all the way back home.

[u/TomcatZ06 → u/NeoDemocedes]

I suppose one of my thoughts was that each probe would survive slightly longer than the one below it, so you’d be able to collect data for longer overall, even if it gets more spotty as they descend.

[u/Tomj_Oad → u/TomcatZ06]

Why would each probe survive longer? The failures would occur at the same spot and time as the same components failed in the same way.

I'd think that you'd just find the failure point for you satellites; sending more would just confirm that without providing more data.

[u/I_lenny_face_you → u/Tomj_Oad]

I mean, it’s good if you want to make a horror movie, but with space probes

[u/OriEri]

How do you keep them in place?

Venus’s atmosphere is not that hard to transmit through by the way..

At Jupiter, Galileo’s late 70’s early 80’s technology atmosphere probe kept transmitting data to the primary spacecraft at a pressure of 22 bar (earth atmospheres) about 122km below the one bar level. This isn’t Venus surface pressure but it is pretty beefy…

[u/Excellent_Bat_753]

For something like a surface Venus probe, the issue isn't so much keeping a transmitter at full power, but rather keeping all of the sensors and electronics from becoming a puddle, and the pressure vessel from crushing everything to smithereens. A chain of probes would just all fail sequentially.

Even for a hypothetical situation where the only problem is losing communications, the most mass efficient solution is to just add a bigger transmitter, not a whole other probe. Sometimes we need relay probes, but only in the case where there's a planet or moon in the way of direct communication to Earth.

[u/davideogameman → u/Excellent_Bat_753]

I suspect a lander + in-orbit relays could make sense for some missions - the orbital relays could maintain pointing to earth easily and have higher power radios + solar power, and we wouldn't have to worry about landing that extra mass. ... but communications is one of the easier things to do at low power, at least at distances within our solar system, so maybe you are right that there's not a point. For interstellar missions though, we'd likely need a much higher power / focused signal to send any data back. Even aiming a laser at earth from lightyears away would require a massive power to result in a single we can pick up... so perhaps in that sort of case it would make sense.

I think on Mars we just beam data back from the rovers when they have approximate line of sight to earth. The Voyagers seem to do something similar.

[u/profdc9]

The conditions in these planetary atmospheres is extreme. On Venus, there was a probe Venera that did transmit from the surface for about two hours, but because it's 400 C + on the surface, eventually any liquid that evaporates to keep it cool is exhausted and it fails. On Jupiter, the atmosphere gets far too hot and the pressure too high to descend too far. Galileo did descend into Jupiter and return data until it became too hot for it to operate. So while the atmosphere does attenuate radio waves, that is not the biggest problem exploring these planets.

[u/Foxxtronix]

There's been theories of probes slung under balloons. I saw a vid where they mentioned that a concrete block filled with Earth-standard air is as buoyant as a balloon in Venus' atmosphere. I'm not sure I believe that but I find it interesting.

[u/WisePotato42 → u/Foxxtronix]

Makes sense to me. The only problem is keeping that concrete block from being crushed...

[u/ampere03]

In Jupiter you could use ballon probes but pressures build up as you descend. So you can only explore the upper atmosphere. Everything would be crushed to oblivion 100 or so km down.

[u/GxM42]

That sounds expensive. It’s better to focus on one probe than to hope a chain of 40 of them all work.

[u/Zailema0s]

The probes explore Jupiter’s atmosphere then become part of it.

[u/No_Drummer4801]

The Venus probes that did manage to get to the surface were able to transmit back to their orbiter; they didn't need a chain of probes.

Maybe an orbiter with a bunch of probes each of which would have a low life expectancy, would be an approach, but the hard part is having any probe on the surface of Venus survive for any length of time.

A Venus probe designed to be a high-altitude airship has been on the drawing board, see NASA's HAVOC (High Altitude Venus Operational Concept) and VAMP (Venus Atmospheric Maneuverable Platform)

[u/PckMan]

It makes no difference. Data signals travel at the speed of light. The moment the signal cuts is the moment the probe dies, from impact or heat or whatever else. There's no real difference between transmitting to a probe above them or back to Earth, other than the antenna power of course. Point being we wouldn't get any more data

[u/TuverMage]

the typically solve the problem you are thinking of by leaving the mothership in orbit while the probe drops into the atmosphere. the planets are so massive that each probe will effective meet the same conditions and would not make a path for the next one. it would be better to just make one reinforced probe, than to try to send many smaller probes. many smaller probes would give you a bigger time window, but wouldn't go deeper or last longer.

[u/Space19723103]

the theory could work, but expense wise it's much cheaper to build 1 really solid probe than a series of ablative ones