The biggest challenge is returning crew from the surfaces of Eve & Tylo. Help and advice, please?

[Scorptrio]

Hello Kerbal universe. I have been playing KSP since it came out on Steam and I've been having a lot of fun over the many months, setting new challenges for myself and developing the craft to succeed at them. In both the campaign and sandbox, I've landed crew on the surfaces of all the planets (that have a surface) and all the moons, both in the stock game and with selected mods. I'm very confident in my ability to put any size and type payload in orbit around, or on the surface of, any object in the Kerbol system. With the exception of two places, I'm also confident that I can return the crew back home after their long journey! I've not been able to return from the surface of Eve or Tylo. I'm working with the Stock game for now, as I'd like to be able to accomplish this without any mods that make it easier, and obviously favorite mods like Ferram Aerospace Research and Deadly Reentry make it more difficult for Eve, when used together. I can get a large, fully fueled craft to the surface of Eve, but it doesn't have enough power to return to orbit. If I give it more fuel, it makes it too tall and it tips over when it lands, or too fat, which increases the drag on the return flight. To make things even more frustrating, I haven't been able to find any videos of anyone who has landed on the surface of Eve, planted a flag, and returned the crew to Eve orbit in the stock game. I've seen people use mods that make it easier, outright cheat, or use over powered sci-fi type parts, but never in the stock game. There is a single video from Scott Manley, in an early version of KSP, where he lands on and returns to orbit from the surface of Eve (probably in a stock game, as he doesn't mention any mods) but he never plants a flag there!

It's interesting that Eve and Tylo are so opposite: you can use parachutes to get a fully fueled craft to the surface of Eve, but can't use parachutes at all on Tylo. On Tylo, there's no atmosphere in your way to get back to orbit, but on Eve there's so much of it, most of the fuel you need is just to get out of the thickest part. The Tylo lander I built gets there just fine, but is almost out of fuel when it does land, with not enough to beat Tylo's gravity on the return.

Can anyone please point me to any of the following?

‣ A video of someone in a recent version of KSP, using stock parts and no flight consequential mods, showing a mission that plants a flag on Eve or Tylo, and returns to orbit.

‣ A craft, using only stock parts, designed to land and return to orbit from the surface of Eve or Tylo.

‣ Advice on how to design and/or fly craft to accomplish the mission of returning from the surface of Eve or Tylo.

Maybe what I'm looking for is already out there, and I just haven't been able to find it, so links are helpful. Thank you very much, to anyone who can help. I'm looking forward to leaping these last two monumental hurdles in KSP before the big 1.0 release.

Edited February 22, 2015 by Scorptrio

[Pecan]

Tylo isn't that bad, but it does take a special lander, as you say - Chapter 8, section 5 of the 'Exploring' tutorial in my signature has the lander I recommend (link to PDF and ships downloads for the whole tutorial in that thread's OP).

Eve IS that bad - my best advice there is to see how people have done it in the 'Challenges' section of these forums.

[Laie]

Your favorite search engine should have helped you.

There's the Eve Rocks Challenge; only very few video submissions, but mostly very detailed picture galleries, and many have provided their craft files for download.

For Tylo, I'd like to point you to the Jool-5 challenge (click my signature), which involves anding on *all* Jollian moons. So Tylo is only part of the mission, but most people try to deal with it early. I don't think there's many craft files, though.

[LethalDose]

I would recommend DasValdez's

series. Should be stock parts and only KER + KAC for mods. He goes through the whole thing: Design to recovery. It's a little long, but informative.

[GoSlash27]

What Pecan said.

Tylo isn't a big deal. Eve *is*.

Tylo lander

Eve lander

Best,

-Slashy

[cantab]

The challenges are slightly different. Tylo is perhaps the highest test of your rocket piloting skills, with the strong gravity that will slam your lander downwards if you aren't careful, and guzzle your fuel if you have to hover for any length of time. But design-wise it's not too bad. Eve on the other hand is a major design and engineering challenge, but the flying is relatively straightforward - though you may need to be good at precision landings if you aren't taking enough delta-V for a launch from low altitude.

[panzer1b]

Tylo (although ive never managed it in a SSTO yet), is extremely easy to pull off, provided you have a high dV and moderate TWR craft. The only relatively hard part is judging when to start the braking burn. too soon and you waste alot of dV against gravity, and too late, well tylo could use a few more craters anyways.

Eve is a massive pain to do (ive managed a 3 stage aircraft style design before), its not only bad atmo, but if im not mistaken, it has the highest gravity of anything in the game (Jool aside, but i dont think its possible to land there anymore), aside from landing, even moving around on eve is painfully slow and dangerous. While its a great challenge, it is in my opinion one of the hardest tasks in the entire game (at least until 1.0 comes out, no idea what the new aerodynamics will do to eve). Prolly the only harder task is getting back into orbit after going deep into the jool atmosphere.

[Pecan]

Tylo (although ive never managed it in a SSTO yet)...

Then try the lander I recommended for Scorptrio, it's a SSTO specifically designed for Tylo.

[Scorptrio]

Thank you; this is the kind of response I'd hoped for. It looks like I'm going to have to go bigger and more stages, to get back home from those desolate places. Some of those craft that did the mission are very impressive.

[Scarecrow88]

Its been quite a while since I went to Tylo and I can't remember all the details of my lander. One specific thing I do remember is that it had a few external fuel tanks which were jettisoned on the ascent as soon as they were empty to keep the weight to as little as possible.

[Zargg]

hopefully this link works, here is my tylo lander. I took the mechjeb off, that is all i use, but there should be some delta v leftover as a buffer:

https://drive.google.com/file/d/0B7fP7yJdpBOFVnotd3dnanRwOUk/view?usp=sharing

you'll also have to manage lift-off thrust so you stay under terminal, and I forget if I aerobraked at Jool or not...

Edited February 22, 2015 by Zargg

[Scarecrow88]

Given that there is no atmo on Tylo to fight against, I didn't think there was a terminal velocity to be concerned about.

[cantab]

Indeed. The most efficient takeoff - and for that matter landing - on an airless body is as horizontal as possible, building or killing your orbital speed without gaining or losing altitude. TWR is a tradeoff between losses because of low TWR and losses because of carrying too much weight in engines, and is of course influenced by staging strategy.

[Laie]

For those who don't know what a constant-altitude landing is, here's

that shows the concept nicely.

And tavert has not only made those engine charts telling you that thousands of tiny engines would be the most mass-efficient, he's also come up with far more useful chart of how TWR affects the delta-V requirements of a constant-altitude landing.

[Starwhip]

There is a harder challenge, but you would be crazy to take it up: Descend to 0 meters on Jool, then back up to orbit.

Anyways, this seems to be largely answered, and as I've done neither, I'm afraid I'll be of little help.

[Zargg]

Given that there is no atmo on Tylo to fight against, I didn't think there was a terminal velocity to be concerned about.

Sorry, meant lift-off from Kerbin. He mentioned stock so I assumed he doesn't have anything automatically doing it.

[Laie]

There is a harder challenge, but you would be crazy to take it up: Descend to 0 meters on Jool, then back up to orbit.

That's surprisingly easy. You need a lot of fuel, of course, and even more to get to Jool in the first place. Big ship. Really big ship.

But you don't actually land anywhere. No need to worry about chutes or legs or putting her down gently. All you need is plenty of asparagus stages. If you can do Eve, you can easily do Jool. It's just more of the same, and fewer complications.

[Starwhip]

That's surprisingly easy. You need a lot of fuel, of course, and even more to get to Jool in the first place. Big ship. Really big ship.

But you don't actually land anywhere. No need to worry about chutes or legs or putting her down gently. All you need is plenty of asparagus stages. If you can do Eve, you can easily do Jool. It's just more of the same, and fewer complications.

Ehh, what's your definition of "hard", then?

Jool's atmosphere is 138,155.11 meters deep, with the density at the bottom being 15 times that of Kerbin.

Eve's is only 96,708.574 meters, and 5 times that of Kerbin.

Really, this is when you ditch rockets and go for spinny things with wings. (With conventional rockets on top, of course. Can't go anywhere in space with only wings!)

[Commander Jebidiah]

As i said in another thread:

How about a skipper or mainsail stage for landing and nuke stage for ascent.

This is for tylo obviously.

Disclaimer: ive never been to tylo or eve, infact im one of the lucky people who hasnt gotten a tylo encounter on jool soi

[Laie]

Ehh, what's your definition of "hard", then?

"More of the same" just isn't hard, I'm sorry. Tylo is very demanding, piloting-wise. And Eve is full of nasty surprises like ships coming apart under their own weight: it's surprising what high gravity and a slight incline can do to a vessel.

[Renegrade]

A small trip to Tylo (ignore the last couple of shots, those are post-KIDS-nerfs designs. From 0.24.2 era)

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Note that this isn't the most optimal design as some design parameters were set by non-landing imperatives... I was also carrying a pair of 48-7Ses to give myself good TWR just before the end of the landing phase - everything went fine with 500 dv to spare, even though I didn't notice the drop tank stage was dry for a very long time :/

One thing to do for a Tylo landing is practice landing on Kerbin. The only really tricky part to a Tylo landing is the last few meters (you don't want to just cut thrust and smack into the ground like on Minmus or Pol or whatever), and just flying around the launchpad can get you acclimatized to the heavy gravity (and Tylo is ligher grav than Eve or Kerbin).

One last word of advice: Don't forget any ladders! The design above was supposed to have ladders up the side to gather science, but I forgot 'em, and had to do insane maneuvers to get the science back (ballistic EVA) as the science equipment was meant to be left behind. Kerbals have about 300n of EVA thrust, giving them 3.2m/s^2 accel - or a bit less than half of Tylo's surface gravity, so you can't EVA-cheese your way past ladder design here!

Here's my advice for Eve: 'Tis a silly place. Let's not go there. (I've done Eve return, and it's not fun. High grav can cause all sorts of bugs and it took something like five design iterations to make working landing gear, excluding bugs)

http://i52.photobucket.com/albums/g13/GoSlash27/KSP/assist_zpsdf2d3d35.jpg

Eve lander

I dub thee, Sir Flying Pancake!

[Pecan]

As i said in another thread:

How about a skipper or mainsail stage for landing and nuke stage for ascent...

The Tylo lander I offered uses a Skipper, no need for a separate stage or engine for ascent.

[-Velocity-]

Tylo is so much easier than Eve it's not even funny. A Tylo landing and ascent into orbit can be accomplished in a single stage (which is useful if you want to reuse your lander to make a bunch of Tylo landings on the same mission). All you need is 5500 m/s dV- IIRC, 5100 is what I found to be required, while 5500 m/s gives you somewhat of a cushion for error.

The two rules I use for designing a Tylo lander (I always make them single-stage vehicles)-

Starting TWR >= 1.3

Total delta-V: >= 5500 m/s.

The more I exceed these numbers, the better.

Here's a medium Tylo lander I made sometime last year. It should still work-

For small Tylo landers, you want to use 48-7S engine, it's by far the best engine for a Tylo lander with its extremely high TWR. I didn't use it on the above pictured lander probably because the number of 48-7S engines would have been crazy huge.

Also, something that will dramatically reduce the size of your single stage Tylo lander is to eliminate the crew cabin. Doing so allows you to decrease the size DRAMATICALLY. This is a "tiny Tylo lander" I made sometime last year. It caries a single Kerbal in a command chair. The Kerbals weight is counter-balanced by a goo experiment on the other side (it took a lot of testing on Kerbin to get it right). It wouldn't work right now because it's lacking reaction wheels (the probe core I used no longer has reaction wheels), but that could be easily rectified. I'd probably sacrifice some of the RCS. It's powered by 8X 48-7S engines.

So Tylo is easy to make a lander for, but difficult to fly it, actually. You have to time your deorbit burns just right. But that's what quicksave and quickload are for, right?

EVE, OTOH is far more difficult. You need like 11,500+ delta-V to make it to orbit from sea level, AND a TWR of around 2 for all the lower stages- and that's an EVE TWR of 2, so like 32, 33 m/s acceleration.

My early Eve landers worked but were mounstrous; the first I made was 700 tons and couldn't even make it from sea level to orbit, it had to be launched from like 2000 meters elevation at least. The second generation I made was better, but still 400 tons, IIRC. Finally, I dumped the requirement for a crew cabin and science experiments; my Eve-bound Kerbals simply live and work in a big habitat that lands separately, and use a rover to drive them over to the Eve ascent vehicle (which I landed somewhere nearby) when they are ready to depart. This allows me to create an Eve ascent vehicle ("EAV") that solely is devoted to getting to orbit. So my Kerbals sit protected by a "wind screen" in command chairs. My current design only has seats for 2, but I could expand its seating to 4 if I wanted, I think. But it would be wasted weight when I'm only planning on two-man Kerbal Eve surface missions.

Including the orbital maneuvering engines- which are jettisoned during landing- the entire thing weighs just 162 tons (the actual ascent vehicle part of it weighs 135 tons). Earlier designs of my EAVs had the parachutes jettison on takeoff, but with these newer designs that have a lower center of gravity, that only saved a few m/s delta-V so I judged it overkill. Anyway, it uses two separate stages of asparagus staging. The first set of asparagus staging uses aerospike engines to get through the lower atmosphere. Stacked on top of this asparagus assembly is a second, smaller asparagus staged assembly that is based on 48-7S engines.

My "EAV Mk6", including orbital maneuvering engine and docking port-

This is just the ascent stages. The first ascent stages are a big asparagus stack based off of the aerospike engine-

This is the second asparagus stack, based on the 48-7S (thirteen of them), that rides on top of the first one-

This is the final stage, the only part of all that mess that actually makes it back up to orbit-

So yea, Eve is incomparably harder than Tylo.

One final note- you must TEST TEST TEST TEST your lander on Kerbin first. An Eve ascent vessel especially moreso than a Tylo one, but the Tylo one will still need testing. Not only should you test to make sure the rockets work correctly, you have to test to make sure that your Kerbals can actually use the ladders to get to where they need to sit!!! Both Eve and Tylo have too high of gravity for your Kerbals to fly using EVA packs!!! The ladders MUST work!

Edited February 24, 2015 by |Velocity|

[-Velocity-]

Pad test-

A little after 2 minutes after launch, the second stage of asparagus staging based on 48-7S kicks in-

6 minutes and 43 seconds after launch, the last engine runs out of fuel. Velocity with respect to Kerbin is 9 km/s, altitude 1250 km-

Mun's orbit crossed at 26 minutes after launch.

That's what it takes to get to orbit from Eve's sea level. Pretty extreme.

Why don't I launch it from Eve, you might ask- well, I tried a very similar craft to this one from Eve, and it worked fine, in 0.24. When I tried to load up that save recently, something was corrupted with it. Anyway, I'm putting together an Eve mission right now, but it will be a while still until I'm ready to use this thing.

Edited February 24, 2015 by |Velocity|

[Renegrade]

Pad test (why the heck aren't spoiler tags working?!)-

They always need a topic for some reason... {spoiler=Because..}

(quote this post to see how I did it if this isn't clear)