Bring a volcanic rock back from Eve

[liamecrow]

Hello,

I'm pretty close to giving up on this, but I accepted a mission to get a volcanic rock from Eve and take it back to Kerbin.   After you complete Duna missions, the game's career mode assumes that Eve landing and takeoff are the most plausible missions.  It seems like many other planetary bodies would be easier to take from.  Are there any plans to make taking off from Eve more possible? It seemed like a huge undertaking just to land on Eve with a ship that can deploy a rover, refuel and also get back up seems next to impossible.  Any tips on this?  It would also be nice if the game added a simulator so you could practice launching your top stage on another body like Eve and see what design gets you the closest, as you can experiment with on Kerbin's atmosphere

[Foxster]

Eve is deliberately a harsh mistress. It's the end-game place to land and return. Not an early or even mid-game destination and return place. 

It will be best to do it Apollo-style, with a transfer mothership in orbit and one or two disposable landers, maybe one with a rover and one with the crew orbit return craft. Alternatively you could abandon the crew and just return a science container to orbit with the science from collecting a rock.   

There is a "simulator" of the cheat menu (alt-f12 on PC) to set your craft in orbit around Eve. Practice the landing, takeoff or whatever and then revert. 

Check out the many threads, particularly Challenges, for inspiration for craft designs. The basics are:

You have to care a lot about drag because of Eve's souposphere.

Have the minimum number of slim engine+fuel stacks.  

After landing, drop anything not needed for the ascent to orbit: Chutes, heatshields, batteries, etc. 

Use the right engines. You need ones with the very best atmosphere isp for the lower stages i.e. aerospikes and vectors. 

You will likely need one of more heatshields to enter Eve's atmosphere. 

[Xd the great]

Has anyone tried stock robotics rotor ascent on Eve? Maybe for the first few km?

[mystifeid]

22 hours ago, liamecrow said:

It would also be nice if the game added a simulator so you could practice launching your top stage on another body like Eve and see what design gets you the closest, as you can experiment with on Kerbin's atmosphere

If you own the Making History DLC, this is exactly what you can do with the mission builder. Put a launch pad anywhere on Eve's surface...

[Foxster]

4 hours ago, Xd the great said:

Has anyone tried stock robotics rotor ascent on Eve? Maybe for the first few km?

Yup. Couldn't make it work. 

Three problems:

Engines made with rotors didn't generate enough lift to get a craft into the air that was big enough to finish making orbit from a near standing start.

Couldn't store or generate enough electricity to power the rotors. 

Tricky getting a craft with several big rotor engines onto the surface.  

Edited July 2, 2019 by Foxster

[HebaruSan]

 

[Foxster]

Good job on sticking with it and getting it to orbit!

I lost the will to live with my craft after about 3 minutes. 

[mystifeid]

4 hours ago, Foxster said:

Good job on sticking with it and getting it to orbit!

Huh ? So you didn't watch the ending then.

@HebaruSan that was a lot of pain for less than 20km height gain. Couldn't believe it when you ran out of fuel short of orbit but then Jeb EVA's and yeah, he's gonna make it, he's gonna ... oh no.

Sorry, but it was pretty funny.

[HebaruSan]

5 hours ago, Foxster said:

Good job

19 minutes ago, mystifeid said:

you ran out of fuel

That was @ShadowZone, not me! Check the upload channel.

[mystifeid]

My mistake...

[Foxster]

Oh, I assumed he made it but got bored before the end of the video. 

Seems he faced similar problems I did when I tried it. Without  thinking it through, I put the final stage of one of my Eve orbit-return craft on top of a 4-prop platform. It could have made orbit with a rocket lifter from the height I could get to with props BUT I forgot that using a rocket stage to get there gave it high vertical and horizontal speed (doh!), whereas the prop craft gave none. I felt a bit silly afterwards when I realised this.

I'm not saying it's impossible but it's no easy option for getting off Eve. 

[KerikBalm]

On 7/1/2019 at 6:26 PM, liamecrow said:

I'm pretty close to giving up on this, but I accepted a mission to get a volcanic rock from Eve and take it back to Kerbin.   ... Are there any plans to make taking off from Eve more possible? It seemed like a huge undertaking just to land on Eve with a ship that can deploy a rover, refuel and also get back up seems next to impossible.

1) It already is possible, its either possible or its not. "more possible" doesn't make much sense. Easier? yes that makes sense. That said, Eve is borderline possible to SSTO from, and you can get to orbit with some pretty large margins (relatively speaking, but you can forget 50% payload fractions like you can get on Kerbin) with a well designed craft.

2) Your rover and ascent vehicle don't need to arrive on the same ship, just close enough. Before ISRU, your ship would basically have to land fueled, so this "refuel" business makes little sense. Just land a fueled ascent vehicle. The 5 atm atmosphere makes landing fairly easy. I normally use a little burst from the engines right at touchdown, from droptanks that detach right after liftoff (along with the landing legs and parachutes). Technically, you don't need a rover either, just 1 kerbal and some luck/physics warp across the surface

1 hour ago, Foxster said:

Seems he faced similar problems I did when I tried it. Without  thinking it through, I put the final stage of one of my Eve orbit-return craft on top of a 4-prop platform. It could have made orbit with a rocket lifter from the height I could get to with props BUT I forgot that using a rocket stage to get there gave it high vertical and horizontal speed (doh!), whereas the prop craft gave none. I felt a bit silly afterwards when I realised this.

I'm not saying it's impossible but it's no easy option for getting off Eve. 

I haven't given it a serious attempt yet (and I doubt I will as I'm doing all my designs in anticipation of Kopernicus updates and playing on a 3x rescale + other tweaks: Eve at 3x is ridonculous, so I tweak its gravity down to 1.25x, and up its atmosphere to 10 atms, but only 1.25x rescaled in height. The atmospheric pressure gave ridiculously bad Isps, even from mountains, so I'm thinking of lowering it to 7.5 atms)

@Brikoleur has done at least a few designs for eve ascent vehicles using rotors. I think his goal was a reusable 2 stage one. The first stage has rotors and rockets, the rockets fire after the rotors max out, and boosts the craft out of the atmosphere, then the 2nd stage circularizes, and you can switch back to the first stage and land it. I do similar things for 3x kerbin, but that's for "recoverable", not really "reusable"... I'm not sure how he intended to re-couple the 2 stages and actually reuse it, but the first step is just having everything intact/nothing destroyed or deleted after getting to orbit.

https://forum.kerbalspaceprogram.com/index.php?/topic/27292-what-did-you-do-in-ksp-today/page/1990/&tab=comments#comment-3628024

His "what did you do today" post

His rotorcraft post

The listed time to launch altitude is 21 minutes though.... ughhhh.... I don't have patience for that.

My plan is to just launch from mountains, and use rotorcraft to fly/ferry stuff around the surface and then bring kerbals and fuel to the mountains for the ascent vehicle launch. I'll be usuing disposable ascent vehicles of course, and landed empty to reduce "shipping costs" - Eve surface ISRU will refuel them

[Guest]

My plan for reuse is to land the orbiter as close to the lifter as I can, then fly in with a service craft that carries drills + ISRU and a crane that can pick up the orbiter and re-mount it. I don’t have a fully functional service vessel yet but have proven to my own satisfaction that I can turn the Kestrel tilt-rotor into one.

Actually operating that in a career game would take a lot of effort and patience. Disposables are much less effort. The 21 minutes to launch isn’t that much of an issue as it needs no pilot intervention for about 17 minutes of that, you can just leave the game running and come back when it’s time to fly to orbit.

[Guest]

On 7/2/2019 at 1:16 PM, Xd the great said:

Has anyone tried stock robotics rotor ascent on Eve? Maybe for the first few km?

Yep, works great. You can pretty easily get to 30 - 35 km and launch from there. You only need about 4500-4700 m/s to make orbit. My lightest Eve lifter for one kerbal weighs less than 6 tons on take-off. 

It takes about 20-40 minutes to fly up there though and it’s real time because rotors are not physics warp friendly.

There are a few craft behind the link in my .sig, including one I’ve tested on a round trip from orbit to surface and back.

[Xd the great]

18 hours ago, Brikoleur said:

Yep, works great. You can pretty easily get to 30 - 35 km and launch from there. You only need about 4500-4700 m/s to make orbit. My lightest Eve lifter for one kerbal weighs less than 6 tons on take-off. 

It takes about 20-40 minutes to fly up there though and it’s real time because rotors are not physics warp friendly.

There are a few craft behind the link in my .sig, including one I’ve tested on a round trip from orbit to surface and back.

[Snip] It worked?

Eve is no longer a headache now.

Edited July 4, 2019 by James Kerman
redacted by a moderator

[Daniel Prates]

On 7/2/2019 at 2:34 PM, HebaruSan said:

 

Hehehe. Visual Enhancements will give you Eve clouds, bur won't make them block the sunrays from reaching the photovoltaic panels. Those first several 1000 meters or so shouldn't be possible with all that cover.