To Eve's surface (sea level) and back - with stock parts only in v1.0.2

[Astyrrean]

I honestly wasn't sure it was even possible. Took me a week but finally, success. It is incredibly hard in v1.0.2 because of the atmosphere changes.

Anyway, Jeb now has "plant flag at Eve" on his list and is happily back at Kerbin's space center.

Visual narrative here:

http://imgur.com/gallery/O9RiR/new?forcedesktop=1

Video of return to orbit of the 800-ton lander from Eve's surface (by far the most complex step) here:

Enjoy. Time to think about a new challenge ...

Astyrrean / Filippo

[selfish_meme]

Amazing effort, I'll just leave this here

http://forum.kerbalspaceprogram.com/threads/123380-The-Bare-Minimum-Eve-Lander-and-Return-Vehicle

[magnemoe]

Amazing effort, I'll just leave this here

http://forum.kerbalspaceprogram.com/threads/123380-The-Bare-Minimum-Eve-Lander-and-Return-Vehicle

I use an variant of your rocket, no ISRU as I fill it up on Gilly and use tug to take it to low Eve orbit, drop tanks for landing and deorbit, this also holds the legs.

It looks like you need an rocket with very high initial TWR to compensate for the low trust, you also need an very low drag core , 133 ton on surface. Know its overbuild as launching from 3500 meter only cost me 7000 m/s so I had 2000 m/s left.

[selfish_meme]

Yeah you need high TWR at least 2, but you cannot go fast until you get high

[Nookos]

Congratz and very brave to go through this with such bad fps.

Is the way mechjeb is doing the ascent in your video the most efficient way? No gravity turn on eve?

[Wiseman]

That's awesome! A landing and return from Eve is something I spend a lot of time thinking about, but when I see the monstrosities you need to pull it off... Well, at least there are enterprising people like yourself to do the hard jobs. Also, welcome to the forums!

[Foxster]

Congratz and very brave to go through this with such bad fps.

Is the way mechjeb is doing the ascent in your video the most efficient way? No gravity turn on eve?

That is pretty much it, yes. 90% shape is the way to go and it's not worth starting any kind of turn until at least 10km. The atmosphere is so soupy if you spend any amount of time trying to turn in it then you'll never make orbit.

To the OP: Well done! Nice to see a different Eve lifter. So far I'd only seen selfish_meme's which was based on mine which was based on another guy's and they are all pretty similar.

[selfish_meme]

That is pretty much it, yes. 90% shape is the way to go and it's not worth starting any kind of turn until at least 10km. The atmosphere is so soupy if you spend any amount of time trying to turn in it then you'll never make orbit.

To the OP: Well done! Nice to see a different Eve lifter. So far I'd only seen selfish_meme's which was based on mine which was based on another guy's and they are all pretty similar.

I saw another one recently which used a mammoth as the first stage for Kerbin and Eve, nice shape and not too heavy. A really neat way to put together an Eve mission.

http://forum.kerbalspaceprogram.com/threads/124166-Eve-for-Valentine-%28Val-s-journey-to-purple-planet%29

Edited June 3, 2015 by selfish_meme

[SciMan]

Here I would have thought starting at least SOME kind of gravity turn would help out at least somewhat, even if you do start it quite high up.

Something I thought might work:

Automatic Ascent Path: OFF

Turn shape: 40%

Turn start altitude: 45000-50000 m

Turn start velocity: 750-1000 m/s

Turn end: 75-80 km

Turn end angle: 5 degrees

Angle Of Attack limiter: ON

- max aoa 7.5 degrees or less

- dynamic pressure fadeout 500kPa

These settings were derived from the settings I use for launching to Kerbin orbit, which are:

Automatic Ascent Path: OFF

Turn shape: 40%

Turn start altitude: 1250 m

Turn start velocity: 150 m/s

Turn end: 45 km

Turn end angle: 5 degrees

Angle Of Attack limiter: ON

- max aoa 7.5 degrees

- dynamic pressure fadeout 500kPa

Usually a 2 stage launcher (2nd stage makes orbit), control surface fins on first stage, starting atmospheric TWR 1.75 (1.5 to 2.0 TWR should work) The higher end of the launch TWR range tends to start being too steep to be efficient.

If this looks familiar, it's because I posted nearly the same thing in the comments of the YouTube video provided by OP.

[Unfawkable]

I'm really more interested in how the heck you landed that entire thing. Impressive nevertheless. I hope one day I manage an Eve return mission.

[selfish_meme]

Here I would have thought starting at least SOME kind of gravity turn would help out at least somewhat, even if you do start it quite high up.

Something I thought might work:

Automatic Ascent Path: OFF

Turn shape: 40%

Turn start altitude: 45000-50000 m

Turn start velocity: 750-1000 m/s

Turn end: 75-80 km

Turn end angle: 5 degrees

Angle Of Attack limiter: ON

- max aoa 7.5 degrees or less

- dynamic pressure fadeout 500kPa

These settings were derived from the settings I use for launching to Kerbin orbit, which are:

Automatic Ascent Path: OFF

Turn shape: 40%

Turn start altitude: 1250 m

Turn start velocity: 150 m/s

Turn end: 45 km

Turn end angle: 5 degrees

Angle Of Attack limiter: ON

- max aoa 7.5 degrees

- dynamic pressure fadeout 500kPa

Usually a 2 stage launcher (2nd stage makes orbit), control surface fins on first stage, starting atmospheric TWR 1.75 (1.5 to 2.0 TWR should work) The higher end of the launch TWR range tends to start being too steep to be efficient.

If this looks familiar, it's because I posted nearly the same thing in the comments of the YouTube video provided by OP.

You need to get above 80km to get out of Eve's atmosphere, usually a 90 to 100km orbit is necessary. Also you need a TWR above 2.0 to get off the ground. Once you do start moving you hit mach at like 150m/s. Straight is easier because of drag causing you to flip until 30-40km, I usually let Mechjeb fly until I get to around 700 m/s then I jockey it through the last air to prevent burning up, then hand it back to mechjeb for the rest.

[OhioBob]

I saw another one recently which used a mammoth...

I studied all the engines and came to the conclusion that, when factoring in both ISP and TWR, the best ones are, in order

1) S3 KS-25x4 "Mammoth" Liquid Fuel Engine

2) LFB KR 1x2 "Twin-Boar" Liquid Fuel Engine

3) RE-M3 "Mainsail" Liquid Engine

4) T-1 Toroidal "Aerospike" Liquid Fuel Engine

Mammoth and Twin-Boar have about the same TWR, but the Mammoth has better ISP. Twin-Boar and Mainsail have about the same ISP, but Twin-Boar has better TWR. Aerospike is a close second to Mammoth in ISP, but its TWR sucks.

[Foxster]

I studied all the engines and came to the conclusion that, when factoring in both ISP and TWR, the best ones are, in order

1) S3 KS-25x4 "Mammoth" Liquid Fuel Engine

2) LFB KR 1x2 "Twin-Boar" Liquid Fuel Engine

3) RE-M3 "Mainsail" Liquid Engine

4) T-1 Toroidal "Aerospike" Liquid Fuel Engine

Mammoth and Twin-Boar have about the same TWR, but the Mammoth has better ISP. Twin-Boar and Mainsail have about the same ISP, but Twin-Boar has better TWR. Aerospike is a close second to Mammoth in ISP, but its TWR sucks.

Funnily enough I'm just building another one, this time using a Twin-Boar. The Mammoth might be marginally better on paper but the extra size and mass don't help it get into the air and everything starts to balloon.

[A35K]

So, in general is it harder do to an Eve return in the old versions with old atmospheres, or in the new version? According to delta v maps older atmo requires a lot more delta v, up to 12,000m/s. However in the new version, thrust decreases in atmosphere, so it is harder to achieve a sufficient TWR. Did you try it in the old version? Which do you think is harder?

[Foxster]

So, in general is it harder do to an Eve return in the old versions with old atmospheres, or in the new version? According to delta v maps older atmo requires a lot more delta v, up to 12,000m/s. However in the new version, thrust decreases in atmosphere, so it is harder to achieve a sufficient TWR. Did you try it in the old version? Which do you think is harder?

Definitely easier now. Well, in a way. The craft can certainly be smaller, needing only 2/3 of the dV now. Getting it out up and out of the soup - now that's a different kettle of fish.

[Signo]

So, in general is it harder do to an Eve return in the old versions with old atmospheres, or in the new version? According to delta v maps older atmo requires a lot more delta v, up to 12,000m/s. However in the new version, thrust decreases in atmosphere, so it is harder to achieve a sufficient TWR. Did you try it in the old version? Which do you think is harder?

You always need to deploy a 100t+ lander and this time it must be sleek too.

However I would say it is almost the same in terms of "pure piloting" apart from the re-entry, you just need a different design compared to 0.90.

[selfish_meme]

Definitely easier now. Well, in a way. The craft can certainly be smaller, needing only 2/3 of the dV now. Getting it out up and out of the soup - now that's a different kettle of fish.

This, getting up from sea level pre-1.0 with a capsule was a daunting task. Most of us landed on high mountains so we could cut 7km from the ascent. My old lander was around the same weight but I would never land it at sea level.

[magnemoe]

My own Eve accent craft is just finished qualifications.

Ship on pad

Decent stage, Just dropped the big drop tank below, ship need to be refueled in LKO and around Eve or Gilly, it will be put into position by an tug.

The tanks with the blue nosecones are part of heat shield structure and is dropped on parachute deployment.

the 1.25 m tanks are landing gear and ground support. I realy love the new tapered fuel tanks and nosecones who is part of the high trust part. Think the Russian patent is expired

I use an 1.25 m service bay with seat as cockpit to save weight and to enable high science return.

Kerbal is dropped in rover and is supposed to do science in close biomes before returning to accent stage. Fallback rover in orbit.

Lander works from 700 meter with dummy payload instead of Kerbal.

[selfish_meme]

If you put a lander can at the bottom you can dispense with the ladders which will probably explode anyway.

[kurja]

you need a TWR above 2.0 to get off the ground.

Are you talking about TWR at Kerbin? Because surely TWR >1 at local gravity gets you off the ground.

That ascent profile though in the video.. =D Circularization burn acccelerated at something like 14g =D =D

[selfish_meme]

Are you talking about TWR at Kerbin? Because surely TWR >1 at local gravity gets you off the ground.

That ascent profile though in the video.. =D Circularization burn acccelerated at something like 14g =D =D

On eve

[magnemoe]

If you put a lander can at the bottom you can dispense with the ladders which will probably explode anyway.

No pod on top, just an seat in an 1.25 meter service bay this way I save weight and can carry out more science.

Ladder is pretty protected by heat shields and boosters on decent, I eject it before takeoff.

[kurja]

On eve

twr >1 does not get your ship off the ground?

[selfish_meme]

No pod on top, just an seat in an 1.25 meter service bay this way I save weight and can carry out more science.

Ladder is pretty protected by heat shields and boosters on decent, I eject it before takeoff.

I'd like to see that sometime, every time I try it shakes itself apart when the Kerbal enters the seat.

- - - Updated - - -

twr >1 does not get your ship off the ground?

Not on Eve

Edited June 5, 2015 by selfish_meme

[Unfawkable]

Not on Eve

TWR relative to EVE in Engineer, or to Kerbin?