Eve Tips?

[Lego_Prodigy]

I have embarked on a manned mission to the pretty planet of Eve in my Spaceplane. But, I need a few tips and advice on conditions of eve and on how to orbit it successfully. 

[korniton]

2 hours ago, Lego_Prodigy said:

I have embarked on a manned mission to the pretty planet of Eve in my Spaceplane. But, I need a few tips and advice on conditions of eve and on how to orbit it successfully. 

https://wiki.kerbalspaceprogram.com/wiki/Tutorial:How_to_get_to_Eve

This helped me a lot. 

[Lego_Prodigy]

loveed up my mission to Eve, and broke off the two rightside engines and the right wing, even with the cheats for no crash damage and unbreakable joints. I had to use the orbit cheat to get there anyway. So I'm a little ways off from another planetary mission. but thanks for that ;D

I guess MK2 parts are NOT for spaceplanes.

[korniton]

13 minutes ago, Lego_Prodigy said:

loveed up my mission to Eve, and broke off the two rightside engines and the right wing, even with the cheats for no crash damage and unbreakable joints. I had to use the orbit cheat to get there anyway. So I'm a little ways off from another planetary mission. but thanks for that ;D

I guess MK2 parts are NOT for spaceplanes.

Just make a nice big overpowered rocket my friend, and you´ll be fine

[Lego_Prodigy]

Currently making a new plane that is just like the MK2 spaceplane that I used, but this time with MK3 parts, all heat resistant parts, and an inflatable heat shield, as that nearly doomed my MK2 ship twice.

[Snark]

7 hours ago, Lego_Prodigy said:

I have embarked on a manned mission to the pretty planet of Eve in my Spaceplane. But, I need a few tips and advice on conditions of eve and on how to orbit it successfully. 

Spaceplanes are a challenge for Eve.  I'm not going to say "it can't be done" (because I'm sure someone would be along shortly to prove me wrong), just that Eve is one of the unfriendliest places for them.

First, Eve's large escape velocity means that a spacecraft arriving will hit the atmosphere going fast, unless they spend a large amount of braking fuel before hitting atmosphere.  It's no problem if you've got a heat shield, but tends to fry anything that doesn't have one.

Second, Eve is brutal to climb from, takes a whole lotta dV to get back to orbit from the surface.  Which means an SSTO is virtually impossible (unless maybe you land at the top of a tall mountain, or something).  Certainly you could design an ascent vehicle in a plane-like form factor if you like (i.e. with bilateral symmetry and wings), but it'll need to drop stages as a rocket does.

I'm pretty sure I've seen some plane-like Eve ascent vehicles that people have made, but my impression is that they're in the small minority.  The most typical Eve ascent vehicle is a rocket.  Hyper-streamlined, high TWR, aerodynamically stable, and engines chosen for good performance under high pressure.

To summarize:

• Unmanned Eve probe with a heat shield that lands and doesn't come back:  very easy.
• Crewed Eve ascent vehicle that returns to orbit after landing:  very hard.
• Spaceplane that enters Eve without a heat shield and returns to orbit:  very very hard.

If you do want to use a spaceplane-style vehicle, your best bet is to use a lot of rocket thrust before entering atmosphere in order to brake (e.g. with a dropped braking stage), and then engineer an appropriate number of stages for the ascent.

[Zhetaan]

@Lego_Prodigy:

9 hours ago, Snark said:

Spaceplanes are a challenge for Eve.  I'm not going to say "it can't be done" (because I'm sure someone would be along shortly to prove me wrong), just that Eve is one of the unfriendliest places for them.

Quite right, but aeroplanes in general work very well on Eve.  You have to design for the environment (it doesn't take a lot of wing at all, you must mind the drag far more than you would on Kerbin, and remember that Eve's got a lot of gravity before you make anything fragile) but there are a few missions where someone landed on a mountain (to take advantage of the fuel savings from a high launch) but took a simple glider to get sea-level science (the wings came off and left a rover; he didn't have to walk back).

10 hours ago, Snark said:

Second, Eve is brutal to climb from, takes a whole lotta dV to get back to orbit from the surface.  Which means an SSTO is virtually impossible (unless maybe you land at the top of a tall mountain, or something).  Certainly you could design an ascent vehicle in a plane-like form factor if you like (i.e. with bilateral symmetry and wings), but it'll need to drop stages as a rocket does.

So far as I can tell, you have to be above 6.5 km in altitude when you take off or else nothing will get you to orbit in a single stage (stock only, of course; there are probably mod engines that can do it).  The only successful Eve SSTO I've ever seen was a flying fuel tank, it finished its orbit with 11 m/s of delta-V left, and it was only an SSTO; it was not a Single-Stage-To-Land-To-Reorbit, meaning that it would need to be dropped there by something else that did not come back.  In the numbers, the delta-V needed for single-stage Eve ascent from that altitude when taking into account the mass ratio of stock fuel tanks requires an engine I_sp of at least 390 seconds on the ground (Kerbin sea level, not Eve sea level).  There are only three engines in the game that have that, but the Dart won't work because it's exactly 390 seconds.  The Mammoth and Vector have 395 seconds, and the extra five seconds give you the room for the payload fraction consisting of wings, engine, landing gear, and probe core (you didn't think this vessel would be manned, did you?  Kerbals are too heavy!).

Generally, for non-SSTO ascents, the difference between orbiting from a mountain launch and a sea level launch is an extra stage (as mentioned before, the difference for SSTOs is a bit more stark).  If not that, then it's two extra stages.  It takes a lot of rocket to plough through five atmospheres of pressure and 1.7 gravities.  The Dart really comes into its own here (it has the best performance at Eve's sea level--it's just not an SSTO engine), and the Mammoth and Vector are both excellent choices, though they are forty seconds less efficient than the Dart.  The Mainsail and Twin-Boar are okay.  Most of the rest work poorly, if at all.

As to the matter of reaching Eve's orbit, remember that Eve is essentially alone in its neighbourhood (Gilly really doesn't count for this).  It's a great place to use for gravity assists (there's a saying that if you can get to Eve, you can get anywhere) but the reason for that is because it's fast and high-gravity.  These factors, however, make it that much more difficult to stop there.  There are some tricks to help with that, but if you're learning interplanetary encounters, it's likely best to take a big transfer stage.

[Laie]

21 hours ago, Lego_Prodigy said:

I have embarked on a manned mission to the pretty planet of Eve in my Spaceplane. But, I need a few tips and advice on conditions of eve and on how to orbit it successfully. 

If you just want to orbit, that's rather easy. However....

Aerobraking at Eve is dangerous, due to high speeds and an atmosphere that's pretty dense even high up (incidentally, all atmospheres except Kerbin's are aurprisingly dense even at altitude). Even if you can withstand the heat, the margin between not braking enough (and flying back to interplanetary) or braking too much (thus landing) is very small. Wings may actually help in that endeavor, if you can withstand the heat.

Landing something on Eve, in and of itself, isn't all that hard. Heatshield, then parachute, and you're set.

If you want to return from the surface, though.... personally, I'm having trouble getting rockets to the surface. Heatshields on the bottom are not enough, as at some time the vessel starts to yaw for (as far as I can tell) no reason at all, exposing bits to the hot air, and ultimately blowing up. The only solution I found is to mount draggy heatshield on the top, as drag anchor. Which looks rather silly.

[bigcalm]

3 hours ago, Laie said:

...personally, I'm having trouble getting rockets to the surface. Heatshields on the bottom are not enough, as at some time the vessel starts to yaw for (as far as I can tell) no reason at all, exposing bits to the hot air, and ultimately blowing up. The only solution I found is to mount draggy heatshield on the top, as drag anchor. Which looks rather silly.

Yes, I had this too.  The problem is that your centre of mass is a long way from the heatshield on the bottom and as a result, once it starts turning, there is likely no stopping it from flipping and then exploding.  However, an Eve ascender is a big thing and it's really tough to keep the centre of mass near the heat shield - your design skills should be going towards the smoothly aerodynamic ascender, not the descent.  You're completely right in mounting heatshields near the top to counteract this - this is by far the simplest solution to this issue and can be applied to most craft.

 

[Lego_Prodigy]

It doesn't have to look professional, it just needs to not explode.

[Cpt Kerbalkrunch]

3 hours ago, Laie said:

If you want to return from the surface, though.... personally, I'm having trouble getting rockets to the surface. Heatshields on the bottom are not enough, as at some time the vessel starts to yaw for (as far as I can tell) no reason at all, exposing bits to the hot air, and ultimately blowing up. The only solution I found is to mount draggy heatshield on the top, as drag anchor. Which looks rather silly.

I solve this problem by having more heatshields on the top than on the bottom. It makes it very stable and, as an added bonus, makes it look a lot better. In fact, it makes it look like exactly what it is; a lander meant for a dangerous atmosphere.

A spaceplane won't have to worry about drag, though. With an inflatable heatshield on the nose, the wings will keep the ship stable throughout the entry. Heat will be the problem. A shallow descent is necessary, or the Big S wings will over heat and explode. I used to use them as stabilizers before I stumbled on to the upper heatshield solution.

[bigcalm]

Yeah, I ended up with Acme Corporation designs like this for planes.  It works but it does look a bit silly I'll admit

[Cpt Kerbalkrunch]

5 minutes ago, bigcalm said:

Yeah, I ended up with Acme Corporation designs like this for planes.  It works but it does look a bit silly I'll admit

They look better when they face the other way. You need a longer ship, though, because they need to attach from the top. Usually not a problem for my Eve landers. They tend to get rather large. 

[GoSlash27]

My best tip: Do not embark on a manned mission to the pretty planet of Eve in a spaceplane.

Best,
-Slashy

Edited April 3, 2018 by GoSlash27

[The Flying Kerbal]

6 hours ago, Lego_Prodigy said:

It doesn't have to look professional, it just needs to not explode.

That right there will surely be the comment of the week!  Simple and profound.

[-Velocity-]

11 hours ago, Laie said:

If you just want to orbit, that's rather easy. However....

Aerobraking at Eve is dangerous, due to high speeds and an atmosphere that's pretty dense even high up (incidentally, all atmospheres except Kerbin's are aurprisingly dense even at altitude). Even if you can withstand the heat, the margin between not braking enough (and flying back to interplanetary) or braking too much (thus landing) is very small. Wings may actually help in that endeavor, if you can withstand the heat.

Landing something on Eve, in and of itself, isn't all that hard. Heatshield, then parachute, and you're set.

If you want to return from the surface, though.... personally, I'm having trouble getting rockets to the surface. Heatshields on the bottom are not enough, as at some time the vessel starts to yaw for (as far as I can tell) no reason at all, exposing bits to the hot air, and ultimately blowing up. The only solution I found is to mount draggy heatshield on the top, as drag anchor. Which looks rather silly.

I just did my first Eve landing and return mission in a couple years.  Both entry and return were significantly harder than the last time due to changes (or outright addition, can't remember how long it's been) of atmospheric heating effects and the aerodynamics model. 

I didn't use any heatshield at all to land my 150ish ton (mostly unfueled) rover/ISRU/ascent return vehicle.  There simply isn't a heatshield large enough for it.  Instead, I put a large de-orbit and entry stage on the bottom of it with about 3000 m/s dV, a starting Eve TWR of about 1, and an insane number of verner thrusters.  The verners were mounted on short, forward wing stubs to move them further away from the CoG.  See image at end of post.  I put the lander into a rather steep descent (i.e., periapsis about 100 km underground) from an altitude of 150 km.  I started the descent engines at like 105 or 110 km.  It worked out well enough.  The verners kept the thing oriented the right way, and it slowed down enough to not burn up.  The engines in the first stage of the lander/rover/base were partly fueled, and assisted the parachutes to achieve a very light touch-down velocity.

The reason I put the lander on a somewhat steep descent curve was 1) To hit a target more accurately (I needed a place I could refuel) and more importantly and 2) I didn't want to have to fight Eve's gravity very long before I hit the lower atmosphere (it wastes dV).

Anyway, it turned out that the whole lander/rover/base worked, but I had some issues driving on Eve.  It's like the ground is high temperature ice or something, because I would just slide down any hill more than 5 degrees and there was no way to stop.  I could overpower the slide and drive up hills up to like 10 degrees, but that was it.  The tires popped a lot too which kept Bill busy.  The bad part was when the tires popped on a 5+ degree hill.  Bill would fix the tires and then the rover would go sliding away from him and he'd have to run like h*ll to snag the ladder  I think next time, I'll just build a better ascent vehicle that I don't have any concerns launching from 1500 m ASL and keep the rover a separate, lightweight vehicle.

Speaking of the ascent vehicle, I had NO IDEA how draggy the windscreen for my kerbals would be.  Turns out the aero model is a little silly, and my windscreen, which I thought would probably slightly decrease drag, was more like a parachute.  I had to jettison the thing early after launch in order to even make orbit (I made a branch save early on in the surface mission just to see how bad ascent would be), even launching from a 2400 m ASL location.  It's nuts. You could probably build a solid metal parachute in the game by just alternating stack widths.  In fact, I plan to try. The aero model's sensitivity to variations in stack width seems MUCH too high, but I'm not an aeronautical engineer. 

For the next version of my Eve ascent vehicle, I plan to put the kerbals inside a fairing.  How to get them in?  Well, IRL, they could just use something called a DOOR.  In game, if they climb up to just outside the fairing on a ladder, you can move the camera inside the fairing and right-click on the command seat and have them board it right through the fairing.  It's kind of silly there is no other way to get into a fairing (other than a lander can inside the fairing already).  I supposed one could use one of those hollow structural fuselages on the bottom and have them climb up through that, but that wastes valuable cross section and weight. 

 

Edited April 3, 2018 by -Velocity-

[-Velocity-]

This is my new Eve Launcher.  Like all my Eve launchers I've made, it's two stacked asparagus-staged groups with a final, vertically-staged stage on top.  I HOPE it's more aerodynamic than the last, but I'm not sure how the game's aero model really works.  Any tips?  I'm not planning on integrating it into a mobile base, it will be stationary, situated on a ISRU-enabled launch pad/base.  The base it launches from will include the ladders the kerbals will use to get inside the fairing.  (Fairings DO shield kerbals from aero forces... right?  Or did Squad screw that up too in the latest patch?  I was reading that service bays do not shield kerbals from aero forces anymore.)   That 11800 m/s dV Mechjeb calculates is WITH kerbal mass simulators installed (4X 0.625m xenon tanks ~= 4 kerbals).

It's quite a bit heavier than the last, but hopefully it doesn't have the drag issues the last one did. 

I am not using Making History, I heard that the parts in it are a little OP and/or buggy.

I'm using the KS-25 engines in the lower asparagus group because they have good atmospheric performance and very good thrust to weight ratio (better than the aerospike) and even better thrust-to-area ratio.  I just can't pack enough aerospikes under this thing, but it's easy to fit enough KS-25s under it. At an altitude of like 1500m on Eve, they still have something like 665 or 670 kN of thrust.    Also, they have a very huge gimbal range to keep your craft under control, though I'm pretty sure that this ship is very close to aerodynamically stable, at least in its first stages.

 

[Lego_Prodigy]

._.

[Foxster]

8 hours ago, -Velocity- said:

This is my new Eve Launcher.  Like all my Eve launchers I've made, it's two stacked asparagus-staged groups with a final, vertically-staged stage on top.  I HOPE it's more aerodynamic than the last, but I'm not sure how the game's aero model really works.  Any tips?  I'm not planning on integrating it into a mobile base, it will be stationary, situated on a ISRU-enabled launch pad/base.  The base it launches from will include the ladders the kerbals will use to get inside the fairing.  (Fairings DO shield kerbals from aero forces... right?  Or did Squad screw that up too in the latest patch?  I was reading that service bays do not shield kerbals from aero forces anymore.)   That 11800 m/s dV Mechjeb calculates is WITH kerbal mass simulators installed (4X 0.625m xenon tanks ~= 4 kerbals).

It's quite a bit heavier than the last, but hopefully it doesn't have the drag issues the last one did. 

I am not using Making History, I heard that the parts in it are a little OP and/or buggy.

I'm using the KS-25 engines in the lower asparagus group because they have good atmospheric performance and very good thrust to weight ratio (better than the aerospike) and even better thrust-to-area ratio.  I just can't pack enough aerospikes under this thing, but it's easy to fit enough KS-25s under it. At an altitude of like 1500m on Eve, they still have something like 665 or 670 kN of thrust.    Also, they have a very huge gimbal range to keep your craft under control, though I'm pretty sure that this ship is very close to aerodynamically stable, at least in its first stages.

....

What's your payload i.e. exactly what is the craft trying to put into Eve orbit?

[-Velocity-]

3 hours ago, Foxster said:

What's your payload i.e. exactly what is the craft trying to put into Eve orbit?

Four Kerbals in command seats attached to a rocket with a probe core, two panels, a  reaction wheel and some batteries and an antenna.  Dry mass about 1.15 tons including the kerbals (see the mechjeb info).  The xenon tanks are kerbal mass simulators.  The payload fraction of this rocket is worse than my last one but it ought to perform vastly better... at least it LOOKS like it will.  I’d appreciate any feedback people who are more knowledgeable about KSP’s aero system might have.  If the rocket is as aerodynamic as it looks, I wouldn’t be surprised if I had enough dV left over upon reaching orbit (from like 1500m)  to escape Eve’s gravity.

The upper asparagus group may be slightly underpowered, but it will kind of hard to fix that... maybe I’ll think of something.  That said, the gravity turn ought to start near the beginning of the second aspargus group so maybe it’s ok.  Maybe if I make the core engine something with higher thrust than an aerospike?(the second aspargus group uses 7-5-3-1 aerospikes).

I’d love to see other designs people have come up with.

Edited April 3, 2018 by -Velocity-

[Freds]

Almost all my missions inside eve atmosphere are one way only, with probes due to my "no kerbal dies, no kerbal are left behind" policy.

The only manned mission to EVE that i  had done was with a spaceplane equipped with karbonite turbines and collectors so it can fly in the atmosphere, and normal LF+O engines plus droptanks to get back to orbit. Due to the karbonite, navigating in eve atmosphere was easy, i even landed near ocean level.
Getting back was the great challenge: The karbonite engines can lift you to +/- 20000M at mach 1 (maximum speed of karbonite turbines), after that, 
you need to burn LFO. I used 2 'Sledgehammer' Air-Augmented Ramrocket from MK2 Expansio mod to get the necessary boost inside atmosphere (that engine, once supersonic, is very powerful)

To get to orbit it was designed to drop everything that is possible - when ascending, the karbonite kit and science instruments was dropped when the LFO droptanks emptied, the craft has 0 monoprop, the only "dead weight" part left was 1 docking port in the lower part of the plane and 1 in the tail, because i wanted to bring it back to Kerbin.

Even with this mods, the plane barely reached orbit (+/- 120Km ). 

I dont have any photos of the craft described, but i have these photos of one test prototypes with karbonite engines that i made to test how a craft handles in Eve atmosphere, passing from low atmo to high atmo, etc. 

 

Spoiler

 

 

[bigcalm]

That's a very pretty plane.  I've never used Karbonite - but have used electric propellers from mods to get around in Eve (with an on-board nuclear reactor) - it's slow but will work pretty much forever.

Here's a one man ascender.  Stock apart from the MechJeb and a small amount of MKS supplies (which basically makes it heavier).

And after I built this eighteen man ascender (which worked), my hard drive ate itself in disgust.  There's an ISRU setup in the middle that's invisible and causes an awful lot of non-fatal explosions on take-off.

[Foxster]

1 hour ago, -Velocity- said:

Four Kerbals in command seats attached to a rocket with a probe core, two panels, a  reaction wheel and some batteries and an antenna.  Dry mass about 1.15 tons including the kerbals (see the mechjeb info).  The xenon tanks are kerbal mass simulators.  The payload fraction of this rocket is worse than my last one but it ought to perform vastly better... at least it LOOKS like it will.  I’d appreciate any feedback people who are more knowledgeable about KSP’s aero system might have.  If the rocket is as aerodynamic as it looks, I wouldn’t be surprised if I had enough dV left over upon reaching orbit (from like 1500m)  to escape Eve’s gravity.

The upper asparagus group may be slightly underpowered, but it will kind of hard to fix that... maybe I’ll think of something.  That said, the gravity turn ought to start near the beginning of the second aspargus group so maybe it’s ok.  Maybe if I make the core engine something with higher thrust than an aerospike?(the second aspargus group uses 7-5-3-1 aerospikes).

I’d love to see other designs people have come up with.

That craft is rather over-engineered.

The biggest battle on Eve is with drag. You will lose loads of dV for every bump, over-sized tank, stack, sepratron, fin, engine, strut and whatever else you bolt on in effort to get the dV numbers up. That leads to the craft ballooning. Whereas the way to go is take stuff away. 

This 25t stock craft can lift 4 Kerbals in chairs inside the fairing to Eve orbit from sea level...

 

Edited April 3, 2018 by Foxster

[GoSlash27]

11 hours ago, Lego_Prodigy said:

._.

Lego_Prodigy,

 Sorry, I know it's not what you wanted to hear... but it's the truth. Getting your kerbals off of Eve is one of the most difficult challenges in KSP. The air density is much higher than Kerbin (most engines won't work at all and those that do work poorly), the gravity is stronger, the DV requirement is higher.

 Eve is not a place you're going to visit successfully in a little runabout spaceplane. If you manage to land without blowing up, you're not getting back out. Eve simply doesn't tolerate that kind of payload fraction without staging.

But you know... All I can do is give you a tip. You don't have to accept my advice

Best,
-Slashy

 

[Cpt Kerbalkrunch]

 

4 hours ago, -Velocity- said:

Four Kerbals in command seats attached to a rocket with a probe core, two panels, a  reaction wheel and some batteries and an antenna.  Dry mass about 1.15 tons including the kerbals (see the mechjeb info).  The xenon tanks are kerbal mass simulators.  The payload fraction of this rocket is worse than my last one but it ought to perform vastly better... at least it LOOKS like it will.  I’d appreciate any feedback people who are more knowledgeable about KSP’s aero system might have.  If the rocket is as aerodynamic as it looks, I wouldn’t be surprised if I had enough dV left over upon reaching orbit (from like 1500m)  to escape Eve’s gravity.

The upper asparagus group may be slightly underpowered, but it will kind of hard to fix that... maybe I’ll think of something.  That said, the gravity turn ought to start near the beginning of the second aspargus group so maybe it’s ok.  Maybe if I make the core engine something with higher thrust than an aerospike?(the second aspargus group uses 7-5-3-1 aerospikes).

I’d love to see other designs people have come up with.

 

Afraid I don't usually go for small and sleek. And since orbital rendezvous around Eve is no fun, I prefer to avoid it whenever possible. This design was for the old Mk1-2. Worked very well in that, but I converted it for a different mission. It now carries the Mk1 Command Module and Service Bay from Eve sea level, on a direct ascent return to Kerbin. I have a little island at sea level I like to test launches from now. The goal is to get from there back to Kerbin without any refueling. This one does it pretty easily.

 

 

As you can see, it's absurdly heavy, though quite a bit more so on the way down.