Tips for landing a probe on Eve with the Deadly Re Entry mod?

[RagnarDa]

As the title says. I've tried to lower my apoapsis as much as possible (I managed around 3000 m/s) with aerobraking but as soon as I get into the thicker atmosphere my probe breaks apart because of the g-forces. Any tips? I was thinking about giving it yet another try and pointing my ship upward from the surface and burning while staying in the upper atmosphere to lose as much lateral velocity as possible without going deeper into the atmosphere. Would that work?

[regex]

Many shallow brakes, using a retro-burn during the initial shallow brake to help get you into orbit? Never tried that with DE...

E: Or are you already in orbit? If so, can't really help you.

[RagnarDa]

E: Or are you already in orbit? If so, can't really help you.

Yes but thanks anyway. I've been using the aerobraking calculator and spent hours (in game days) circling Eve and slowly decelerating by aerobraking in the topmost atmosphere. Its only when I try to enter the atmosphere to land that my ship decelerates too fast (because of the thickness of the atmosphere) that it breaks apart every time. Was the mission doomed to begin with or are there some trick I can use to not hit the Eve atmosphere like its a brick wall? I really like this mod by the way, it adds a new level to an already though game that I was beginning to feel I mastered...

[Hodo]

Never tried to send a probe to Eve, but I do use DRE. Have you attached a heatshield to the probe? I would put on on there attached to a decoupler so you can get through the atmosphere then blow it when you are through the worst of it without having to have the additional weight stuck to the bottom of the probe.

[RagnarDa]

Thanks for the suggestion! Tried that and pointing my rocket skyward to stay in thinner atmosphere longer but it didn't work unfortunately. I think my design was doomed from the beginning and now I believe I maybe should have equipped lift surfaces to stay in thinner atmosphere longer to decelerate. That would make the aerobrakemaneouvers more difficult but I guess it would be possible. Another possibility would be to employ retro-rockets but that comes with other problems...

[kalizec]

I'm stuck on this as well.

Performed an aerocapture coming from Kerbin with a probe such that it orbited Eve with a Pe in upper atmosphere.

Each time after aerobraking I lifted my Pe again such that each maneuver effectively only lowered Ap.

After 10 such maneuvers my Ap was below 150km and I've tried Pe's ranging from 70 to 76km.

With approx. a 3km/s reentry I don't see how I could go much lower with regards to velocity without bringing retro-rockets.

All attempts so far result in ruin.

The probe uses 2 heatshields stacked into each other Mk1-2 heatshields for what otherwise would be a 2 ton probe.

Both heatshields don't get a chance to properly ablate. Instead they blow up because of overheating.

The first one manages only to ablate 25% of it's total.

The second one doesn't even manage 5% before it overheats.

Is it possible the max. temperature for these heat-shields is set too low?

Or am I simply doing something wrong?

With regards to reality, I'm sure that the Venera probes the Russians sent to Venus didn't use retro-rockets for their landers.

As Eve is supposed to be the equivalent of Venus I think it should be possible to land on Eve by just aerobraking.

[Bluegobln]

You could solve this by making more heat tolerant special custom "Eve shields" for entering that atmosphere. Say they are made out of more resistant materials, balance them by making them much heavier or something (or some other method that makes sense). You can recycle existing models and simply adjust their part cfg file or you can go the full way and custom build em! (Which is its own adventure, and while I am much more attuned to that I admire yours as well).

[pizzaoverhead]

It sounds like DR needs some higher temperature shields. Venera 4 hit 11,000 °C and pulled 300 G on Venus entry. It used a heavy heat shield with an active gas-based cooling system.

Edited December 6, 2013 by pizzaoverhead

[RagnarDa]

But was it heat that killed your probe kalizec? In my testing I think it was the over-g's. You can tell what killed it in the flight report (press F3). Even though I'd love a new heat-shield with som kind of heat exchanger, I don't think it would solve the problem of that nothing in KSP can tolerate 300+ G. Maybe a new parachute with a very high terminal velocity and that would work in the very highest atmosphere and then be cut once you go lower? Could this be made out of the stock parts, like do any of them have a very high drag factor compared to weight?

[Hodo]

I managed to land a probe on Eve using DRE+FAR+RemoteTech2, I do not suggest trying that with the signal delay it was less than fun. Anyway after 100+ attempts this is what I managed.

The landing wasn't perfect it landed on its side, knocking off several solar panels. If I ever send a crew down there I will fix them.

[RagnarDa]

I thought some more about this. What are normally used to cushion a dramatic deceleration? Well in cars they use airbags. So maybe I should try the airship mod...

[RagnarDa]

Love the last picture. It looks like it is putting its fist in the air in a "win"-gesture...

[aquilux]

The original poster's question remains unanswered.

A) He believes he is entering as gently as possible.

His craft is not overheating.

C) His craft is breaking apppart due to the high g-forces incurred by the dense atmosphere.

What advice is there to be given that would help in this scenario?

[Hodo]

The original poster's question remains unanswered.

A) He believes he is entering as gently as possible.

His craft is not overheating.

C) His craft is breaking apppart due to the high g-forces incurred by the dense atmosphere.

What advice is there to be given that would help in this scenario?

The only thing I took from my 100+ attempts to land my probe on Eve was. Weight and speed have a MUCH larger affect on Even than on Kerbin.

My probe was just under 5 tons didn't have a heat shield because it was to much additional mass, and came it at a VERY shallow re-entry angle. I reduced the PE till it was at 65-75km above the surface of Eve. The speed it hit 70km at was less than 2300m/s. I deployed my chutes around 10km, not much of a choice, was at the mercy of a 74 second signal delay. The part that helped the most was when I hit 75-70km I was tumbling the craft, to spread out the heat over the entire surface of the probe. It wasn't until it has slowed down enough that it was programmed to right itself. I think the most Gs it pulled was 10 maybe 11Gs before the chutes deployed.

I may have a slight advantage over the OPs problem because I also run a mod that reinforces the joints so I don't need 400 struts.

[Mmmmyum]

From what I understand you're lowering your trajectory for the final approach?

[Hodo]

From what I understand you're lowering your trajectory for the final approach?

Yes before I even started my atmosphere interface I was down at just above the atmosphere at 100km X 100km. That is roughly 4km above the atmosphere of Eve. I reduced my PE down to 65-75km and let drag reduce it further. Much deeper than 65km and the probe burned up from a combination of heat and G-forces. The heat I combated by just letting the probe tumble through the upper stages of the atmosphere, from about 80km down to 45km. From there the probe was programed to right itself nose facing prograde and let it decent naturally till it was at its prescribed time to deploy the chutes.

If I hadn't been so frustrated with using the flight computer in RT2 I would have taken better notes to help out others, but it was a nightmare.

[RagnarDa]

Thanks! This save was from 0.21 so I no longer have it, but I will retry it now. Going to try bringing a big rocket with a large t/w to do a powered descent as if the planet didn't have an atmosphere. Maybe that'll work.

[Mmmmyum]

Ah, glad you got it worked out. I haven't been to Eve with this current set of mods (mainly RSS, done DRE though).

[euphrates95]

TONS of drogue chutes. I landed a probe on Eve with DRE, but I was using RealChutes, so I deployed drogues as I entered the atmosphere to slow the craft down. Even then it was a close one and I lost the majority of the ablative shielding.

[Ascension Islander]

Hodo, I think you're the only other person I know to have accomplished an unmanned landing on eve with remote tech 2 and signal delay combined with deadly reentry. I'll post my pictures once I get home. Let me recommend the smart part pack that comes with the space shuttle engines pack (also available separately). I was able to just drop the probe in at ~70km pe and the smart parts did all of the parachute/landing leg/antenna/solar panel deployment and heat shield decoupling based on altitude sensors and timer delays.

OP, maybe you should try installing FAR. It makes the atmospheres much less soupy, and I imagine is what allowed myself and Hodo to do it successfully.

[Hodo]

OP, maybe you should try installing FAR. It makes the atmospheres much less soupy, and I imagine is what allowed myself and Hodo to do it successfully.

Yeah FAR makes things definately different, and more realistic, which is why I run it. But I can't stand that stand the stock KSP aerodynamic model, which at best is crap. But it was no easy task to land that probe on Eve with the RT2 plugin. It took me over a hundred tries and was by far the most frustrating thing I have ever done, and I doubt I will EVER attempt that again.

[Ascension Islander]

I'm telling you those smart parts are the way to go. Took me two tries and the only reason the first one screwed up was because I forgot to activate the smart parts

[TheCanadianVendingMachine]

I just landed a probe on eve, I recomend a periaps at around 60km

[Hodo]

I'm telling you those smart parts are the way to go. Took me two tries and the only reason the first one screwed up was because I forgot to activate the smart parts

I have no doubt about that, but I didnt have them yet, and I still dont, but I am working on fixing a few things and testing out MJ in the RSS mod with RF,and all my other mods listed in sig.

[Ascension Islander]

Now that I'm home, here's my completely automated unmanned eve descent with RT2, FAR, and DRE:

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