SESRV: Smallest Eve Sample Return Vehicle

[saik0]

How far is it from the oceans?

Never bothered to measure. Eve is coming up on my list of map tiles to make, I could tell you sometime next week when it's done.

[Climberfx]

Never bothered to measure. Eve is coming up on my list of map tiles to make, I could tell you sometime next week when it's done.

Put your maps on Wiki!

[numerobis]

I want to be clear on the parameters: what's the start point? Is it from a landing trajectory just outside the atmosphere, or from liftoff at Kerbin?

[tavert]

They say Eve ocean is made of liquid fuel. But i don't think so, if it was liquid fuel, Eve would have burn a long time ago, near like this to the sun...

Not if there's no oxidiser in the atmosphere...

numerobis, welcome back and FYI from the middle of page 1:

Measure mass from Kerbin launch. Also, as mentioned above, you may undock and redock to parts of your own craft, but not any other craft.

I was actually able to get a safe landing in Eve's ocean by using the pair of nuclear transfer engines to help slow down instead of ditching them on re-entry. I added another tiny last stage and more thrust on the penultimate stage and got to orbit successfully from sea level, but had basically no fuel left in orbit and no docking port. My last stage is so tiny that even the small docking port will cost a lot of delta-V, so I'll have to play with things a bit more to see whether I want to leave a transfer stage in Eve orbit and rendezvous with it to get back to Kerbin, or add more stages for direct-ascent return.

My ascent vehicle, after dropping the transfer engines and the transfer/landing tanks and parachutes, is around 35-36 tons. It's using around 11500 m/s delta-V to get to orbit from sea level, but its TWR is lower than optimal (as can happen when you're trying to minimize total mass). More tweaking to do, I think.

The mountaintop landing and rover route will definitely end up winning out here, I'm building something that works at sea level for the challenge of it.

[Climberfx]

Not if there's no oxidiser in the atmosphere...

Sun has no oxidizer...

Fusion, just temperature (or and pressure) to reaction...

[tavert]

Have to be several times bigger than Jupiter to sustain fusion. Although the KSP planets are so tiny yet heavy relative to the real ones, their density might actually be up there...

[Climberfx]

No need in real life to be bigger, but more dense yes, and hot. But i my mind an ocean of fuel, still blow all the planet a part. Lol.

I don't discart the possibility of existence for then on game.

By the way, will be marvelous, when we get the 0.20 update with resources to explore, and made the return from Eve a common thing.

[numerobis]

The hard part of returning from Eve is the liftoff itself; even with empty full tanks, it's tricky.

As for oceans of fuel being flammable, that's only if there's oxidizer. Similarly, on Kerbin (and Earth), the atmosphere is packed full of highly flammable oxygen -- but it only burns if there's fuel.

Edited April 29, 2013 by numerobis

[saik0]

OK I've poked around a bit. There are no places above 5km that drop off steeply enough to be anywhere near sea level. If you want to land at any of the peaks, be prepared for a long drive.

[lump]

On the point about the sun's fusion, even at it's core it is too cold to sustain true fusion, what actually happens is via quantum tunneling, there's a very small chance that two hydrogen atoms will just be fused together by appearing next to each other, and then on for heavy hydrogen to helium e.c.t. this has a very low chance off happening but due to the massive amounts of hydrogen in the sun it happens enough to be sustained, this is why we have so much problems with fusion rectors, we genuinely have to get it up to fusion temperatures rather than simply being so big it happens anyway. The sun's heat does aid in the process though as it makes the atoms more "lively" and therefore gives a higher chance of this happening.

[Horn Brain]

I think I can do this with a 30-odd ton vehicle, 8 small SRBs (to get the vehicle to orbit in one piece), a separate rover, one big orange tank in LKO and about 3/4ths of one in LE(ve)O.

Here is an album with the vehicle in orbit: http://imgur.com/a/SbYDz#0

Read the descriptions beneath the pics for more info.

Dante has well over 10 km/s of delta-V. The final payload to orbit will be only the very top probe and two small toroidal tanks with three ant engines. I may just barely be able to do the full return with Dante alone, but I'm expecting to have to do a retrieval mission. That can be quite light, though.

[A Fat Pokemon]

I am having a ridiculous time finding the 'Delete ccomment' button...

Edited May 6, 2013 by A Fat Pokemon
Where is the delete button?!

[Francesco]

I am having a ridiculous time finding the 'Delete ccomment' button...

I don't think it actually exists...

[Ekku Zakku]

I'm pretty sure there is one, let me make this post here and find out for you XD

Nope, doesn't exist anymore. Used to be a checkbox if you went to edit your post.

Edited May 6, 2013 by Ekku Zakku

[salaja]

this wasn't done for this challenge, but i guess it meets the criteria. i landed some kerbals at sea level on eve and returned them to kerbin.

this was done in 0.20, and the only mod used was the engineer mod for the design, it was removed for the flight.

entire imgur album (i only included a few of the images below).

reddit post

as for a sampling device/container, i chose to use the kerbals space helmets:

leaving eve:

orbital EVA, keep in mind that the kerbal helmet is the sample container, so the sample is transferred to the new ship:

back on kerbin:

mission/ship details:

1665 tons/541 parts at launch,

14 ton interplanetary return craft (jettisoned into a stable orbit around eve),

156 tons/223 parts lander (160 tons while descending to the surface),

4 tons abandoned on eve surface (2 kerbal lander-can and landing gear).

all rules met:

1. parts were all stock - done

2. must have something to take a sample - kerbal space helmet - done

3. craft must involve a pod - a pod is 'involved', one is used on the interplanetary return ship (why is this even a rule?) - done

4. land back on kerbin - done

Edited May 28, 2013 by salaja

[saik0]

As of 0.21 Eve has a new peak. It is located 7541 meters above sea level at -158.47446, -24.99460. If I remember my trig correctly it's 15km due south of the nearest body of water "as the crow flies". To invent some numbers, say we took a rover 20 m/s downhill and 10 m/s up, you could make a round trip in a little over 30 minutes. So, things just got interesting.

[Francesco]

thanks for reporting this!

< warps until next Eve transfer window >

the question now is... how much delta-v does it take to reach orbit from there?

science time!

[Death Engineering]

An ocean landing may be possible if your landing has a floatation device on the bottom. While building a reusable rocket shuttle that has "heat shielding" in order to conform to the rules in the Duna Permanent Outpost Mission Architecture Challenge, I dropped a lander into the water and to my amazement, the thing totally floated! If I'd built it with engines above the water line and a decoupler, I have no reason to believe that taking off from a floating platform on Eve wouldn't be possible. The floatation device/heat shield is an adapter and some structural panels (all stock).

That being said, in 0.20, I did an Eve landing and return mission with a stopover on Gilly. Landed 5244m asl and was still pretty tough to get back into orbit from that altitude. From 0m asl (floating on the ocean)? Thats going to be something special. I'm still working on the Duna challenge, but I may make a side-trip to Eve to see if I can float an orange tank on the ocean.

Floating lander

Eve return lander

[metaphor]

thanks for reporting this!

< warps until next Eve transfer window >

the question now is... how much delta-v does it take to reach orbit from there?

science time!

It takes about 350 m/s less delta-v than it did before. (You only have 92% of the atmospheric losses at 7540 than at 6450)

[saik0]

It takes about 350 m/s less delta-v than it did before. (You only have 92% of the atmospheric losses at 7540 than at 6450)

Also the proximity to water makes a high elevation landing much more feasible.

[tavert]

I had forgotten about this challenge, but I've been working on an 8.14-ton craft that should be able to do the round trip. 1 jet for Kerbin ascent, ion transfer and return stage, and rover-mobile Eve lander/ascent vehicle. Will bring a Kerbal in a seat for the transfer and parachute Kerbin return, on a ladder for the Eve landing, driving up the mountain, and ascent. It isn't manned via a pod and wouldn't satisfy the "sample return" part of this challenge (except I guess via the "Kerbal helmet sample" approach) since the Eve orbit rendezvous would be via jetpack... and I'm not looking forward to the hours of ion burns.

Edited August 2, 2013 by tavert

[Ekku Zakku]

What engines are you using for the Eve ascent?

[tavert]

Sorry for the bad camera angle there. It uses the new inline Rockomax 48-7S engines. The radial versions were already frequently the engine of choice for small things when TWR was required, but placing just a single one was a fiddly affair. The new inline version is a tiny bit heavier, but has 50 seconds better Isp, which more than makes up for the extra 0.01 ton mass in fuel saved. And the FL-T100 tank and its good mass ratio unlike the small tanks we previously had makes for a good combination.

I have a few more pictures that show the Eve ascent vehicle configuration (different landing setup, and slightly more fuel), and it successfully ascending from near the 0.20 highest peak (using the KSPX version of the parts that only differ in paint job) here: http://forum.kerbalspaceprogram.com/showthread.php/41584-Tiny-Eve-ascent-vehicle-6-23-tons-KSPX-MechJeb

Edited August 2, 2013 by tavert

[magnemoe]

Note its exist an mods for sample returns.

http://forum.kerbalspaceprogram.com/showthread.php/33323-PLUGIN-PARTS-Development-0-20-tek-Industries-Science-v0-3-0

I'm using it myself now, downside it the weight of the samples, 100 rock is 0.5 ton and 100 liquid is 0.2 ton.

My Eve sample return used an airship who makes things far easier, it also let me fly to water and land to get samples, Atmospheric samples was gathered during aerobrake.