Slaying the purple beast!

[Tourist]

She stares out at me from the darkness.... the great purple nemesis, taunting me, daring me, laughing at me. The only planet I've yet to tame*. The beast known as Eve.  

I'm no beginner. I've flown spaceplanes back from the surface of Laythe. Duna is almost a second home. I've "landed" on Tylo.** 

But despite my achievements there is one giant purple elephant in the corner of the room. Eve.

For awhile I've been avoiding it, always finding another planet or moon to direct my efforts, but finally the time has come... its time to slay Eve***. 

So Kerbalnauts, If you have conquered Eve, tell us the tale so that I may steal your ideas learn from your great success. 

Tell us how you did it, tell us about your design philosophy for the mission. What are your Eve slaying tips.   

 

 

* Ok, I haven't landed and returned from Moho yet either. Alright, or Eeloo.

** the probe core and a solar panel survived.

*** by that I mean, land on, and return. I don't have a death star capable of actually destroying a planet... yet. 

[Temstar]

Use command chairs inside cargo bays to save weight on pods. It may not be pressurized but at least it's got doors that can close unlike Mark Watney's MAV convertible superleggera.

[Windspren]

5 minutes ago, Temstar said:

Use command chairs inside cargo bays to save weight on pods. It may not be pressurized but at least it's got doors that can close unlike Mark Watney's MAV convertible superleggera.

It was a ragtop. Much better than a convertible.

 

Off topic: If KSP ever gets life support, the resource should be called Potatoes. Because Watney. Yes.

[Temstar]

Once you have your return payload shaved down to as light as possible asparagus staging becomes unwieldy because some of the later stages will be tiny. One way to get around the form factor is a technique called Vertical Asparagus Staging.

Instead of a normal ring shaped asparagus,  you can arrange each stage on top of each other. Each stage have its own pair of radial engines and fuel lines to move the fuel up the stack. Once the bottom most engine runs out of fuel you can just ditch with with a regular decoupler.

Here is the craft on its final stage climbing to orbit:


Here it is jettisoning its on the surface:


So 3 pairs of normal asparagus staging boosters, then centre core, then the single vertical asparagus stage stacked on top of the core stage. All engines firing at lift off.

[Hannu2]

Atmosphere of Eve has changed from previous versions. Now ascent is easy and descent is nightmare. I am in same phase as you, developing manned Eve lander. However, I do not want to see how others have solved the problem.  This kind of technical difficulties are best what KSP can give.

I have tried couple of shapes of an ascent device. All of them achieve easily orbit, even from low altitude, if I hyperedit them to the surface. But all of them flips during reentry. It seems difficult to find a good weight distribution for both, ascent and descent.

[Taki117]

The trick with landing on Eve is taking it slow.  Skim the atmosphere a couple of times and you should be good.  Keep your draggy parts in back and your not draggy parts up front.  Once you're on the surface and ready for take off, ditch everything you don't need, and I do mean everything.  No landing gear, no parachutes, no airbrakes, if you don't absolutely need it for liftoff, ditch it.  After that ti's a simple matter of having enough dV.

[Foxster]

Tips:

Streamline it - Eve is very draggy. At the top, using a mk1 pod with a mk16 parachute (same low drag even if deployed) is an excellent combination of low drag and high temperature tolerance. The wider the tanks and the more stages you use the draggier it will be. Low drag can be even more important than saving a few kg. A few thin stages is best. Mk1 size engines are your friend because of this.  

Use Circular Intakes as nosecones on the top (and bottom if no engine there) of all tanks. They are the best low weight+drag nosecone. If they over-heat then use the Adjustable Ramp Intake instead.    

Throw away everything you don't need before or as you start to lift - ladders, de-orbit tanks, landing struts, docking ports, fins, etc. 

Your ascent profile is vital. Start turning too low and you will burn up, too high and you will need too much fuel to make orbit. Straight up to 30km and then a gentle turn might be good for your craft. Be prepared to make a lot of ascents with different profiles to get it right.      

Aerospike and Vector engines are your friends on Eve. They are efficient and slim. A Terrier makes an excellent last stage because of it's high Isp at high altitude, whilst maintaining a low-drag profile on the way up.  

You can aerocapture and aerobrake from interplanetary speeds! Everything needs to be in the heat shadow of a heat shield. Remember that drag occlusion only works for adjacently attached parts but bow-wave heating occlusion works for the whole craft. You will need some air brakes deployed as you enter the atmosphere but even when deployed these need to be entirely behind the heat shield; rotating them radially on placement will make this possible (pretend you don't see the clipping).   

[OhioBob]

My only manned mission to Eve was during v0.90.  I had accepted contracts for something like "Eve base on wheels" and "plant a flag on Eve".  I went ahead and constructed a mission that landed three Kerbals in a large mobile base to fulfill the contracts.  However, it was basically a one way mission with no immediate plan to bring them back.  After a couple decades stranded on that purple rock, I decided it was finally time to figure out a way to bring them back home.  I had never launched from Eve before so this would be my first attempt.

Not wanting to build some huge monstrosity of a spacecraft to bring them to orbit all at once, I brought them up one at a time using a small lifter with a command seat.  Unfortunately I've lost all my screenshots from those missions, but I still have a save of the vehicle (remember this was pre-1.0, so I didn't have to make everything aerodynamic or have heat shields):

There were to be a total of four launches from Kerbin - the three landers/lifters and a return ship.  I saw no reason to dock them together into one huge vessel, so they all flew to Eve independently.  The plan was to make three separate landings, drive the mobile base to each landing site, have one Kerbal board each of the three lifters and launch, have the return ship rendezvous with each Kerbal in orbit, and have each Kerbal board the return ship via EVA.  After all three Kerbals were aboard the return ship, they would have to wait in orbit for the next available launch window, and then they could finally all come home.

To validate that the lander/lifter worked before sending all three of them, I first sent one along with the return ship.  The plan was to bring one Kerbal up to the return ship and, if that worked, I'd send two more landers/lifters at the next launch window to bring up the other two.  Good thing that was the plan because what I didn't realize when I designed and tested my lifter, a Kerbal adds 94 kg to the mass of the vehicle when he's placed in a command seat (he doesn't add anything when he's in a pod).  Everything seemed to be going exactly according to plan, but I ran out of propellant before attaining orbit.  Fortunately I did a quicksave before launching.  I tried again, same result.  I couldn't figure out why the results weren't matching my simulations until I discovered I was 94 kg overweight.  I then launched unmanned and I achieved orbit exactly as I had planned it (my first ever successful launch from Eve).  That told me that my design method was correct, I just needed to upsize to account for the extra 94 kg.  (In retrospect, I probably could have left the command seat and used the EVA pack to gain the last bit of velocity needed to attain orbit, but I didn't think of that at the time.)

At the next launch window I sent one redesigned lander/lifter (pictured above) to fetch one Kerbal.  The mission went off without a hitch and I had one Kerbal aboard the return ship.  By now I was getting pretty good at landing close to my target.  Once entry started I had no control over where I was going to land.  My only control was in selecting the altitude and location of periapsis when performing the deorbit burn.  I don't remember exactly, but I think all of my landings were inside of 10 km from the mobile base (I think the closest was about 3 km).

Confident now in my design and procedures, I sent the last two landers/lifters at the next launch window and rescued the last two Kerbals.  At the first opportunity, they rocketed out of Eve orbit, traveled back to Kerbin, and safely splashed down.  With all the time spent waiting for launch windows, and the time spent in transit, it took about 5 years to complete all the flights needed to bring those little green guys back home.  I'd like to think there was a nice tickertape parade for them after their long awaited return.

Edit:  I forgot to mention that I was lifting off from an elevation of about 900 m.  I therefore needed more delta V than Temstar's design - about 12,000 m/s total.

 

Edited May 10, 2016 by OhioBob
added note

[KerikBalm]

5 hours ago, Temstar said:

Once you have your return payload shaved down to as light as possible asparagus staging becomes unwieldy because some of the later stages will be tiny. One way to get around the form factor is a technique called Vertical Asparagus Staging.

Instead of a normal ring shaped asparagus,  you can arrange each stage on top of each other. Each stage have its own pair of radial engines and fuel lines to move the fuel up the stack. Once the bottom most engine runs out of fuel you can just ditch with with a regular decoupler.

Here is the craft on its final stage climbing to orbit:


Here it is jettisoning its on the surface:


So 3 pairs of normal asparagus staging boosters, then centre core, then the single vertical asparagus stage stacked on top of the core stage. All engines firing at lift off.

This was obviously done pre 1.0.... the aerodynamcs are horrible, the Isps are too high (the TWR thus too high), you have no issues with heating... etc.

But in some ways its easier in 1.0 (less total dV needed if you make your ship aerodynamic)... all I can really say is that your pictured design is probably not applicable to the current state of the game. (also, you don't show what altitude you ascended from... which makes a big difference on eve)

[Temstar]

3 hours ago, KerikBalm said:

This was obviously done pre 1.0.... the aerodynamcs are horrible, the Isps are too high (the TWR thus too high), you have no issues with heating... etc.

But in some ways its easier in 1.0 (less total dV needed if you make your ship aerodynamic)... all I can really say is that your pictured design is probably not applicable to the current state of the game. (also, you don't show what altitude you ascended from... which makes a big difference on eve)

It's true, done around 0.19.1 if I remember correctly. The ship was launched from 4974m, hence the rover as I wanted to go to the ocean.

I know of course the current aerodynamics are different, the main point I was trying to make was that there's a way to stack small stages vertically and still get the same effect as asparagus staging, which might be useful to wring some extra delta-V out of the last few stages.

Edited December 8, 2015 by Temstar

[xendelaar]

here is my 1.04 mission report on my visit of the purple rock. Maybe you can borrow some ideas for your 1.05 design.

 

Returning from Eve is a great challange!  Good luck and have fun! 

[pasukaru76]

I just today completed most of my 1.0.5 mission to the surface of Eve. I still need to get my Kerbal back home, but she made it back to Eve orbit (from 1100 meters above Eve sea level) and the return vessel is currently being refueled at Gilly. The mining operation on Gilly was very important for my mission, as my Eve lander needed to be refueled in order to safely land on Eve. Then it had to be refueled again by a mining rover on the surface of Eve. Here's a couple of pictures:

The "lander" has a ring of 6 Vector engines on the bottom with a lander can in the middle, so I didn't need a ladder to get out onto the surface. I used the crew transfer feature to get my Kerbal into the capsule on top of the rocket before launching from Eve.

 

[fourfa]

Just recall for those of us in career/science mode that if you use crew transfer, you cannot transfer science.

[pasukaru76]

Very true. Though this was in career mode, I already had the whole tech tree unlocked when I started the mission, so the losses from having to transmit the science didn't matter to me.

[fourfa]

Which is probably true for everyone by the time they get to Eve.  I just like seeing a really, REALLY big number when I return to Kerbin and recover the crew and science.

[Mikki]

Let your Kerbals give Eve a everlasting hug...

Good luck, prepare a rescuemission, don`t forget!

[KerikBalm]

*placeholder for my 3 kerbal eve lander* pics to come later today*

If you optimize well enough, you can get 3 kerbals to the surface, at eve sea level, and return, with a full set of science instruments (getting results for the atmosphere on the way down too) for about 100 tons.

Yesterday I launched the tug that will take the lander to eve... although I need to refuel the tug (or use the eve lander's fuel, and refuel at gilly).

The tug has about 1,500 m/s dV with a 108 ton payload, so... I should be able to do everything without ISRU at gilly (my crew are taking a seperate ride to eve, to put a fuel depot and science lab station in orbit, and there's a seperate return vehicle).

Reentry and ascent of the lander already tested with HE.

Basic composition:

2 vectors side boosters and an aerospike core (fuel lines feed fuel to the aerospike core from the side boosters/tank

2 side mounted drop tank stacks (the vectors provide enough thrust that no engines under this stack are needed)

1 terrier upper stage

mk1 pod and mk1 crew cabin

jettisonable heat shields, landing legs, parachutes, and science packages.

[Tourist]

Some terrific ideas here, thanks for sharing!!

My most recent attempt has been inspired by many of your designs. 

It blew up during entry into Eve's atmosphere... (I also realized I neglected landing legs.... It's always the little things you forget). I think a simple design change will get me onto the surface... Alas have not yet had the time to test. 

Short design concept. It uses mk1 cockpit capsule and fuel tanks, a terrier for the final stage, and a vector as the primary engine. Four radially attached fuel tanks, with aerospikes providing fuel to the vector. Every thing fits behind 5 interlocking heat shields.

Tempted next time to turn off heat (merely as a simulation) to test proof of concept as a ascent vehicle... Then, if it works sort out the heating issue. 

Anyway, once again, great responses! Cheers.

Edited December 9, 2015 by Tourist
fixing mistakes

[TopHeavy11]

I've never even considered going to Eve, but I have gone to Moho, just not back...

I would imagine though that you would need either a HUGE lander and ascend-er, OR a very fuel efficient one.

Your call.

[GoSlash27]

On 12/7/2015, 11:23:41, Temstar said:

 One way to get around the form factor is a technique called Vertical Asparagus Staging.

Instead of a normal ring shaped asparagus,  you can arrange each stage on top of each other. Each stage have its own pair of radial engines and fuel lines to move the fuel up the stack. Once the bottom most engine runs out of fuel you can just ditch with with a regular decoupler.

 

 

 I believe the community normally refers to that as "twisted candle" staging.

 

 

I had conquered Eve a long time ago. It involved a highly complex technical approach called "cheating"

http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/KrakBadger

Infinigliders (which produced free thrust from lift) were a thing and Kraken drives (which produced free thrust from part collisions) were a thing. So I put them together in one unholy contraption that allowed me to fly to and from Eve's surface without using any fuel.

Of course... none of this is of any use to you whatsoever...

Best,

-Slashy

Edited December 9, 2015 by GoSlash27

[NecroBones]

You're all making me want to go back to Eve really badly. The last time I did a round trip there was before the new aerodynamics. Actually its worse than that. It was back in 0.23.5.

 

Edited December 9, 2015 by NecroBones

[pasukaru76]

5 hours ago, Tourist said:

It blew up during entry into Eve's atmosphere... (I also realized I neglected landing legs.... It's always the little things you forget). I think a simple design change will get me onto the surface... Alas have not yet had the time to test. 

I also had a lot more trouble getting big things safely down to the surface than I had with the ascent. I tried heat shields and airbrakes. Even with a 80,000m periapsis, I burned through a full 3.75m heat shield and then my main engines before slowing down to a safe speed. In the end I abandoned the heat shield in favor of using the engines to brake on the way down.

 

[Foxster]

1 hour ago, pasukaru76 said:

I also had a lot more trouble getting big things safely down to the surface than I had with the ascent. I tried heat shields and airbrakes. Even with a 80,000m periapsis, I burned through a full 3.75m heat shield and then my main engines before slowing down to a safe speed. In the end I abandoned the heat shield in favor of using the engines to brake on the way down.

 

I'm a little surprised at. The craft I posted a pic of above can aerocapture from interplanetary speed with a Pe of 65km and come into land in the same pass. Wonder what we are doing different? 

[fourfa]

14 hours ago, KerikBalm said:

Basic composition:

2 vectors side boosters and an aerospike core (fuel lines feed fuel to the aerospike core from the side boosters/tank

2 side mounted drop tank stacks (the vectors provide enough thrust that no engines under this stack are needed)

1 terrier upper stage

mk1 pod and mk1 crew cabin

Interesting, I hadn't noticed that the crew cabin is actually lighter than the Mk1 inline cockpit.  Don't give away the whole design (testing is half the fun), but what's your dV at Eve launch?  I'm stuck at 6600 (vacuum) with acceptable sea level TWR with this configuration.

[Tourist]

11 hours ago, TopHeavy11 said:

I've never even considered going to Eve, but I have gone to Moho, just not back...

I would imagine though that you would need either a HUGE lander and ascend-er, OR a very fuel efficient one.

Your call.

Closest I've come to landing on Moho is scattering bits of my ship over its surface. After the transfer and the orbital insertion burn, I had just enough fuel left to get suborbital, but not enough left to slow down. 

Currently I'm going for light and fuel efficient. I've tried a few behemoths, but frankly, while I can do large complex asparagus staging, I find it fiddly and not particularly fun.