Eve and back?

[techgamer17]

On 12/13/2016 at 11:41 PM, bewing said:

If you want a lot of science experiments, then you will probably need a rover. The nice part about that is that you can leave it behind. The hard part is building and testing the rocket that gets your Kerbals back to orbit from the ground. So you start by designing and testing that. So I'd say your mission goes like: launch all the parts from Kerbin, assemble and refuel in Kerbin SOI if necessary, travel to Eve, drop a rover and land it, drop your lander, EVA to the rover, zoom around and take your data, load all the data into your lander, get back to orbit, move all your data into some little Kerbin return vehicle, get back to Kerbin, then maybe transfer your experiments and Kerbonauts to a Kerbin RV, and deorbit.

So maybe a few spacetugs to drag all this junk to Eve, and one to drag your Kerbals and experiments back to Kerbin in some tiny capsule. Maybe expend a spacetug or two to help deorbit your rover and lander at Eve. But definitely that lander is the tricky part.

In all fairness i could just send an unmanned craft to eve with a rover and just scrap taking kerbals for now. Furthemore, i also have a life support mod installed and i cant imagine the pain id have to go through to get them the supplies as im not too far into the tech tree. 

[Blaarkies]

5 hours ago, techgamer17 said:

In all fairness i could just send an unmanned craft to eve with a rover and just scrap taking kerbals for now. Furthemore, i also have a life support mod installed and i cant imagine the pain id have to go through to get them the supplies as im not too far into the tech tree. 

You definitely need to send a Kerbal to Eve's surface and return them safely to Kerbin in this decade...you must choose to do this and the other things, not because they are easy but because they are hard!

Seriously it's a great feeling, once you pull off an Eve landing and return mission, you could be talking with real astronauts one day, listening to them going to space and reply with "yeah, but have you ever landed one Eve? "

But life support will definitely make it more difficult...maybe an extra living hab rover for the kerbal to wait in? just drive that up to the lander and wait till ISRU fills up the ascent vehicle

[Lukaszenko]

I've been messing around with an EVE lander for a while now, optimizing and testing the tiniest changes. Just a few tips:

• TWR: VERY important. The more the better, because the gravity losses are MUCH greater than the aerodynamic ones (if you streamline properly).

I'm talking a TWR of at least 2 and maybe even 3 (Eve, atmospheric), especially on the first stage, before the weight of the engines gives diminishing returns. You might think otherwise, but it's worth it, despite the expense of delta-v. Vectors are really good here.

• STREAMLINING: Aerodynamics is VERY important. Just like the gravity losses, it can quickly make your theoretical delta-v a moot number. Gravity and atmosphere are the biggest bottlenecks in getting to orbit.

Seemingly stupid things, such as solar panels or radiators (the ones that go "flush" with the fuselage), can make a difference. Even a fairing that angles a bit too high or a bit too low, can make a difference. It's subject to experiment, but it's good to know. Use pointy nose cones, they are are demonstratively better than even the narrowest docking port, despite the temptation (that at least I've had) to use one. I've even experienced the same amount of engines at the bottom of the rocket (supposedly secluded from the airstream), give hugely different performance depending simply on how they were positioned. That said, some wings and winglets give surprising little drag, making them quite useful when compared to the (much needed) stability they provide.

• CONTROL: I've seen the theoretical delta-v take a dump when I realized I can't utilize it, because my rocket goes out of control.  

Stabilizing wings and/or powerful vectoring engines give good control and can make a large difference between orbit or not. 

[Lukaszenko]

By tweaking the above, I've made this ~50t, ~6000 dv vehicle which can claw its way from Eve surface to its orbit, with hundreds of delta-v to spare:

It's not the lightest, but it's compact, simple, and can be piloted by any idiot. It needs some sort of gravity turn, but it can handle any that I threw at it. It can be made even simpler.

 E.g. remove the aerospike for less performance (but still orbit capable), as per the the TWR point.

It can also, with few modifications, be augmented to give you ~1000 dv to spare in orbit, even despite a sloppy ascent. 

 

 

 

[Lukaszenko]

Of course the full landing package gets a bit more hairy. Still, at ~75 t it's easily enough to be hurled by one launch from Kerbin.

 

 

Edited January 4, 2017 by Lukaszenko
Updated pic

[Blaarkies]

14 minutes ago, Lukaszenko said:

By tweaking the above, I've made this ~50t, ~6000 dv vehicle which can claw its way from Eve surface to its orbit, with hundreds of delta-v to spare:

It's not the lightest, but it's compact, simple, and can be piloted by any idiot. It needs some sort of gravity turn, but it can handle any that I threw at it. It can be made even simpler.

 E.g. remove the aerospike for less performance (but still orbit capable), as per the the TWR point.

It can also, with few modifications, be augmented to give you ~1000 dv to spare in orbit, even despite a sloppy ascent. 

 

 

 

I love the design, sleek and pretty. How do you land that, and how does the kerbal get into the command pod?

How is the drag losses compared to a 2.5m only rocket?...the 3.75m parts add lots of cross-section based on my experiments

[Palaceviking]

On 13/12/2016 at 11:35 PM, techgamer17 said:

If this is already a topic then my bad. I've done kerbin to duna and back with a realtively large lander and 2 kerbals. It required several stages and an orbit stage to fly around Duna while I land, do experiments then take off and redock with it. After completing this mission, I'm now eager to go to eve but everyone says it's really difficult because of its thick atmosphere like the real Venus. How might one go about landing AND returning with a Kerbals and a lot of science experiments (I use a lot of mods too to make it more realistic e.g mechjeb,scatterer and universal storage) 

I would seriously consider doing this unmanned first because of the life support complications. and maybe you could drop supplies /isru ready for your manned mission, I've tried eve a couple times and it has sadly been the doom of a few kerbals

[Foxster]

1 hour ago, Palaceviking said:

I would seriously consider doing this unmanned first because of the life support complications. and maybe you could drop supplies /isru ready for your manned mission, I've tried eve a couple times and it has sadly been the doom of a few kerbals

Eve has gotten a little easier in the last release of KSP. Not easy by any means but just a little less insta-doom. 

The atmosphere is more forgiving in terms of heating on ascent. This means you don't have to go vertical for 25+km before turning to avoid heatplosion as you did before. You can start a gravity turn at, say, 5km now. This means you can save quite a bit of dV without being quite so likely to die horribly. 

[Palaceviking]

Yes, i remember instaboom on contact with eve, I may give it another whirl if it's only slightly more forgiving, also does anyone else feel that if you return from eve you've completed ksp? I think that's why I've been putting it off

[Foxster]

1 hour ago, Palaceviking said:

Yes, i remember instaboom on contact with eve, I may give it another whirl if it's only slightly more forgiving, also does anyone else feel that if you return from eve you've completed ksp? I think that's why I've been putting it off

Ah but once you have done a manned return to Eve you have to it with a <25t lander. Then you need to do it with a science rover on-board and visit at least 5 biomes. Then land and return a crew of three. Then land the lander on disposable wings rather than use 'chutes. Then...

[Sharpy]

On 18.12.2016 at 11:06 AM, techgamer17 said:

Gilly is a complete b**ch to land on because of its really low gravity.

Bullsh.

Gilly is wonderful for landing and all that stuff. You just need to approach to it like to an asteroid and not a planet. Forget everything KSP was teaching you about efficient orbits, orbital mechanics, Oberth, suicide burns and all the fancy stuff.

Switch speed display to Surface. You won't need Orbit speed on Gilly, ever.

Point your nose at where you want to go, then fly up to that place, completely ignoring the fact Gilly has any gravity. Turn around and stop over the surface, some 5 meters above it. Let the gravity set you down.

Don't worry about orientation. If you land nose-down and engines-up, you can flip your rocket using reaction wheel.

Construction of a base resembles construction of a space station, except you can leave kerbals and stuff lying around, and they won't float away when left unattended and unattached.

If you want to drive a rover, that is tricky, but give it RCS and treat it as a dinghy for flying everywhere around and you'll be fine.

If you leave things, try to leave them on the surface, and not above it. They would be entirely unharmed by the fall, but the physics sometimes will glitch at the moment of collision surface and delete them if left unattended.

And watch your kerbal EVA propellant levels. You really don't want to be stuck without jetpack. It's pretty much equivalent to being stuck without jetpack in deep space.

 

 

Edited January 3, 2017 by Sharpy

[bigcalm]

All 3 of my Eve rockets failed (got some great screenshots though!).  The plane I sent on the offchance with the feeling "This will never work" actually worked relatively well.

However, I know what I did wrong (and version 3 was oohhhhhh so close)!  Next transfer window I'm sending something that will, this time, make it!

I should add to my caveats

* The more aerodynamic your craft is, the less delta v you will need.

* There's no point in packing stupid amounts of delta v into it if it's just going to turn on it's side (possibly the same as point 1).

I refuse to use Hyperedit and/or cheat menu - any suggestions on how to test the aerodynamics for an Eve ascent vehicle on Kerbin?

 

[Foxster]

56 minutes ago, bigcalm said:

I refuse to use Hyperedit and/or cheat menu - any suggestions on how to test the aerodynamics for an Eve ascent vehicle on Kerbin?

When it comes to Eve you really do want to indulge in HyperEdit and/or setting orbit on the cheat menu because you will need to try lots of iterations before you get a successful craft. Think of it as time in the simulator - you practice first and when its all good you then fly the proper full mission. 

You really can't simulate the extra atmosphere height, increased gravity and denser atmosphere on Kerbin (without cheating that is) in any useful way. 

Edited January 3, 2017 by Foxster

[Rath]

Maybe you could shove a drogue chute on the bottom for testing?

[Lukaszenko]

On 1/3/2017 at 7:20 AM, Blaarkies said:

I love the design, sleek and pretty. How do you land that, and how does the kerbal get into the command pod?

How is the drag losses compared to a 2.5m only rocket?...the 3.75m parts add lots of cross-section based on my experiments

Thanks. The pic is just the naked ascent vehicle I used for testing. I added labels to the picture of the whole stack I posted above. You can see the lander and some ladders attached to one of its sides. They are jettisoned prior to takeoff. It enters the atmosphere using an inflatable heat shield on both ends (for stability). It also has a science package and a 4 parachutes above the command module (jettisoned using a launch abort system). The 4 parachutes slow it enough to land on its landing foot. 

I quickly ruled out using only 2.5 m parts, due to how long and unstable for landing it would be, but I will still be interested to test it.

Anyway, I still hadn't flown a full mission with this thing. I am doing that right now, and taking some pics. 

EDIT:

So I did change the lower tank to a 2.5 m one as per your suggestion. Indeed it still easily made it to orbit, despite less fuel (and ~4 tons less weight and a sloppy ascent). I couldn't do a proper back to back test, however, but there's clearly a difference.

Still, I like the looks of the previous one better 

Edited January 4, 2017 by Lukaszenko

[Blaarkies]

15 hours ago, Lukaszenko said:

Thanks. The pic is just the naked ascent vehicle I used for testing. I added labels to the picture of the whole stack I posted above. You can see the lander and some ladders attached to one of its sides. They are jettisoned prior to takeoff. It enters the atmosphere using an inflatable heat shield on both ends (for stability). It also has a science package and a 4 parachutes above the command module (jettisoned using a launch abort system). The 4 parachutes slow it enough to land on its landing foot. 

I quickly ruled out using only 2.5 m parts, due to how long and unstable for landing it would be, but I will still be interested to test it.

Anyway, I still hadn't flown a full mission with this thing. I am doing that right now, and taking some pics. 

EDIT:

So I did change the lower tank to a 2.5 m one as per your suggestion. Indeed it still easily made it to orbit, despite less fuel (and ~4 tons less weight and a sloppy ascent). I couldn't do a proper back to back test, however, but there's clearly a difference.

Still, I like the looks of the previous one better 

44tons, thats really efficient! My lander was about 38tons fully fueled(but i only lifted a command seat inside a fairing). Maybe me going 5-stages wasn't as efficient as I thought at first.

I used the same idea of extendable ladders on decoupling pylons(saw in in some video of a RO venus landing), and landing legs on big pylons. It landed empty with little fuel in the bottom tank. this gave me a low COM which leads to landing on 45 degree slopes easily. The shape profile was 2.5m only, so the small probecore+seat craft was kept inside a 2.5m fairing at the top. Used ISRU to fill up, while the kerbal landed in a separate rover elsewhere to collect science enroute to the EAV.