[Stock 0.16] The Eve Project =Guard13007 Industries=

[mark_mazz]

I have a recommendation, but I'm not sure if it will work. Would it be possible to load multiple stages of parachutes? So you could use one parachute stage to land on Eve, and another to land back at Kerbin, so you don't have to waste precious fuel on landing.

I'll make a concept rocket and upload an image and possibly a download in a while.

[ltpeanuts]

Hey mark, welcome to the forums and such.

As it stands the general plan here is a 2 rocket system. The first is an orbiter to get from Kerbin to Eve, which will carry 2 of our brave crew, the second will be a lander stage carrying just one Kerbal, which will be launched separate from the orbiter. This saves us a bunch of fuel, and thus mass, but it also adds the challenge of orbital rendezvous. That being said, I'd love to see your designs.

[mark_mazz]

Here's the final stage sequence for my example lander, with pictures.

Edited August 29, 2012 by mark_mazz

[ltpeanuts]

Overall I like the design, but can that lander reach Kerbin orbit?

[Thobewill10]

How do you know any of these landers will be able to leave eve? it's got 170% of Kerbin's surface gravity, so it'd need to be a lot more powerful to get up.

[ltpeanuts]

How do you know any of these landers will be able to leave eve? it's got 170% of Kerbin's surface gravity, so it'd need to be a lot more powerful to get up.

Not to mention 500% atmo. My personal plan is to use a spaceplane to take advantage of the nice thick atmosphere, one of my better designs is posted a few pages back. The problem there being finding somewhere to land and take off from.

[Guard13007]

Update time! After much work and many lives sacrificed to science, my team of "engineers" has come up with the Arrowhead. It's a nice small ship, easy to land and glides like a dream(75m/s at 6500m, pitched to 18 degrees seems to work best.) So far I have no system of getting it to Eve, but that will come in time.

As always feel free to use my ships in any way you please so long as you credit my design. Any and all help is welcome

Credit will always be given where credit is due. I think the final version will have a long credits list to various people for their ideas that are incorporated. xD

The main two questions I have with that vessel, how does it behave with a rocket stuck on it? And how well does it get itself into orbit?

I have a recommendation, but I'm not sure if it will work. Would it be possible to load multiple stages of parachutes? So you could use one parachute stage to land on Eve, and another to land back at Kerbin, so you don't have to waste precious fuel on landing.

I'll make a concept rocket and upload an image and possibly a download in a while.

Parachutes can be staged in the way you suggest, however the massive amounts of fuel and huge rockets that would need to be created to do everything with one vessel is staggering. Powered landing being required is an issue with testing on Kerbin, and may not end up being an issue on Eve. Even if it is, the current solution should translate well to Eve, and we can land with very minimal fuel usage. Not an issue.

Please send in design ideas anyhow! ^^

@ltpeanuts Thank you for explaining that (it gets tiring having to repeat it so much xD) and hopefully orbital rendezvous won't be too much of a challenge in the end. I bet it will be even better once they add docking...which isn't happening with 0.17, but one can always hope anyhow.

[Russian Flame]

Cool lander but do you even know if you have enough fuel left to get back to kerbin

[ltpeanuts]

The main two questions I have with that vessel, how does it behave with a rocket stuck on it? And how well does it get itself into orbit?

It's a little unstable with a rocket strapped to its ass, but it flies ok if you keep it from tipping over. As for getting into orbit, I used my normal flight plan with no real problems and got a 150x150 orbit. Doesn't need much in the way of runway either. Basically fly up to 4 km and build up speed untill the jets are nearly dry, turn up to 75-80 degrees, and at about 6.5k fire the main engine and eject the 2 jets. Climb to around 35-40k and by then your apoapsis should be above atmo. You should be able to coast and circularise with half a tank remaining.

Also it glides like a dream. A 4 hours and still going dream.

[mark_mazz]

Overall I like the design, but can that lander reach Kerbin orbit?

I tweaked the design and added a rocket to get it to Eve. I was able to get it into orbit, land with the lander, get back into orbit with the lander, and land with the capsule safely, so it seems promising. It is, however, quite unstable when you are taking off, so getting into orbit takes a little flight prowess, but an experienced pilot can do it with not too much work.

http://filesmelt.com/dl/Eve_Concept_Craft.craft

[Guard13007]

Overall I like the design, but can that lander reach Kerbin orbit?

Without the fuel glitch, there's no way that thing can make it back. I honestly can't believe it even gets into orbit.

How do you know any of these landers will be able to leave eve? it's got 170% of Kerbin's surface gravity, so it'd need to be a lot more powerful to get up.

Pretty much we don't. I need to try out the Eve engines that what-the made to assist with this project.

It's a little unstable with a rocket strapped to its ass, but it flies ok if you keep it from tipping over. As for getting into orbit, I used my normal flight plan with no real problems and got a 150x150 orbit. Doesn't need much in the way of runway either. Basically fly up to 4 km and build up speed untill the jets are nearly dry, turn up to 75-80 degrees, and at about 6.5k fire the main engine and eject the 2 jets. Climb to around 35-40k and by then your apoapsis should be above atmo. You should be able to coast and circularise with half a tank remaining.

Also it glides like a dream. A 4 hours and still going dream.

Wow, where do you find the time? I just downloaded the design and tested it. Do you use a joystick to fly? Because that thing is way too hard to fly accurately. If it were mine, I would've put an Avionics Package on it instead, because planes are too hard to fly with and ASAS, remember one of the goals is to make a design that is easy to fly for novice pilots.

I tweaked the design and added a rocket to get it to Eve. I was able to get it into orbit, land with the lander, get back into orbit with the lander, and land with the capsule safely, so it seems promising. It is, however, quite unstable when you are taking off, so getting into orbit takes a little flight prowess, but an experienced pilot can do it with not too much work.

(By orbit I assume you mean into Kerbin orbit. If it gets to escape velocity and then is recaptured, that's cool too, but still not enough.) If it can only do that, it's still a far way off from making it to Eve and back.

[mark_mazz]

We should establish some sort of test to see if a plane is capable of making it to Eve and back. For example, Take off, orbit around the mun and back, land on Kerbin, take off and orbit around the moon again, and land back on Kerbin once more. Assuming you have ample fuel left after each of these tests, I assume that means the rocket is promising. Should this be the official test for seeing if a rocket is at least close to making it to Eve and back?

[mark_mazz]

Also, I had another idea. What if we were to send a return module to Eve, kill the crew (sorry) so that the capsule is empty, send another lander to land on Eve, send the lander in Eve orbit, and send the crew back to Kerbin in the return module? Would this be allowed (considering we have to kill the crew of the first rocket but nobody has to know about that)?

[MSGundrium]

Also, I had another idea. What if we were to send a return module to Eve, kill the crew (sorry) so that the capsule is empty, send another lander to land on Eve, send the lander in Eve orbit, and send the crew back to Kerbin in the return module? Would this be allowed (considering we have to kill the crew of the first rocket but nobody has to know about that)?

I'm sorry, that just seems like an awful idea. killing the first batch to make way for the second? Not plausable. Our best bet? put one half meter ship on a full meter ship. Use the Full meter launching stage to get the smaller rocket to Eve and just spam parachutes to keep it safe. then launch the half meter ship out of the planets gravity well. Simple as that.

[Guard13007]

We should establish some sort of test to see if a plane is capable of making it to Eve and back. For example, Take off, orbit around the mun and back, land on Kerbin, take off and orbit around the moon again, and land back on Kerbin once more. Assuming you have ample fuel left after each of these tests, I assume that means the rocket is promising. Should this be the official test for seeing if a rocket is at least close to making it to Eve and back?

If I could remember how much dV it takes to do these orbital maneuvers (to orbit -> to Mun .. and repeat) and knew how to calculate dV usage and stuff, this could be a good way to measure how well a rocket will perform. (With probably a few different additions to change it up.) Going into a low orbit of the Mun and back twice could be a pretty good measurement, but I really don't know.

I've been trying to learn how to calculate dV and other things, but haven't made much progress yet. If I can figure out a good test (preferably without having to go to all the math I will be trying) I will report back.

Your other idea...I'm sorry but it doesn't even make sense. Why send three ships? The lander goes down, comes back up, rendezvous/crew transfer, return. If the lander can't make it back up, then we proceed with testing the return vehicle with our remaining crew. We will have to re-design the lander/lander LV, but we would at least know the return ship is capable of returning (unless it isn't, in which case, time for another re-design).

As a side-note, Scott Manley (szyzyg on YouTube) is also working on this project (or rather, he's working on his own designs by himself), I suggest anyone wanting to get to another planet starting watching his videos, especially the most recent few that have been about this topic.

[r_rolo1]

All I can remember from heart is that you need +/- 840 m/s of dV to do a munar injection from a 100*100 km orbit and that you need +/- 1300 dV from a 70*70 orbit to get a Kerbol orbit Pe consistent with the Eve orbit Nova posted in page 1 if you burn near the right place ( that is, +/- 40º from the daylight line into the sunny side ). So I assume that a rocket with 2200+ dV can deliver something to Eve... that means that in theory a rocket that can do the munar injection twice will be enough for Eve ( that is, liftoff, munar injection (, circularize around the mun? ), burn to Kerbin (, circularize ? ) and do a munar injection again ) ... it might be even a little too much, but as you need some extra fuel to do corrections ( and to put the ship in Eve orbit ? ) it probably fits well enough

On Scott Manley ... well, I steal ( er... borrow, I mean ) a lot of him for a long time and he actually seems to have seen some of my designs, given his new heavy lander design ( or atleast has got there independently ). Even today I gave him a suggestion on a fuel lines issue he had

Edited August 30, 2012 by r_rolo1

[Jeebs24]

Would this be a proper simulation?

1. Orbit Kerbol

2. Land on Kerbin (simulate landing on another planet)

3. Take off from Kerbin

4. Orbit Kerbol again

5. Get back home to Kerbin

[ltpeanuts]

Wow, where do you find the time? I just downloaded the design and tested it. Do you use a joystick to fly? Because that thing is way too hard to fly accurately. If it were mine, I would've put an Avionics Package on it instead, because planes are too hard to fly with and ASAS, remember one of the goals is to make a design that is easy to fly for novice pilots.

Hey so the easiest way to fly the Arrowhead's jet stage is to use the navball. Keep the ASAS on hit caps lock to turn on fine controls. While you're flying use the F key to make adjustments, it's pretty easy once you get the hang of it. As for hours of glide testing, I run those on my laptop so I can do redesigns and flights on main battlestation.

[Guard13007]

All I can remember from heart is that you need +/- 840 m/s of dV to do a munar injection from a 100*100 km orbit and that you need +/- 1300 dV from a 70*70 orbit to get a Kerbol orbit Pe consistent with the Eve orbit Nova posted in page 1 if you burn near the right place ( that is, +/- 40º from the daylight line into the sunny side ). So I assume that a rocket with 2200+ dV can deliver something to Eve... that means that in theory a rocket that can do the munar injection twice will be enough for Eve ( that is, liftoff, munar injection (, circularize around the mun? ), burn to Kerbin (, circularize ? ) and do a munar injection again ) ... it might be even a little too much, but as you need some extra fuel to do corrections ( and to put the ship in Eve orbit ? ) it probably fits well enough

On Scott Manley ... well, I steal ( er... borrow, I mean ) a lot of him for a long time and he actually seems to have seen some of my designs, given his new heavy lander design ( or atleast has got there independently ). Even today I gave him a suggestion on a fuel lines issue he had

I commmented a link on that video to your Eve I, like hey, your rocket is looking like this guy's rocket! xD

As for a test, because we want to have a ship with extra fuel, I think there should be two tests, one to simulate for far you can take the lander (go into deep space and go into an orbit a bit lower than Eve using a non-optimal flight path (we want to keep it easier) without using any fuel that is supposed to be for landing/takeoff), and the second one is just to get into Kerbin orbit, de-orbit, dump everything but the lander, land with the lander (preferably trying it both with a steep angle and a shallow angle to see how well it can take it), and return to orbit.

And actually, there needs to be a third test, for the return vehicle to get to a bit lower an orbit than Eve, then burn off a bit of fuel, and all it's RCS (I think it should have RCS onboard to make orbital rendezvous easier), then return to Kerbin. Since you already know the proper burn times and places, you should be writing up the guide on how to get there, and I should start flying things and following your guide half-incorrectly (to see how much the design can withstand error and still make it).

@Jeebs24 The idea is two ships fly to Eve, one stays in orbit with fuel to bring them both back (well, the crew member), and the other is able to land and return to orbit. Your test presumes we are trying for one massive ship.

@ltpeanuts I envy your ability to just have a spare computer for this kind of thing. I'm also gonna assume you have air-conditioning and envy you for that as well.

[Jeebs24]

@Jeebs24 The idea is two ships fly to Eve, one stays in orbit with fuel to bring them both back (well, the crew member), and the other is able to land and return to orbit. Your test presumes we are trying for one massive ship.

I was thinking of two ships in mind as well and exactly the way you just described. I was just wondering if it was a good Eve route mock-up.

[silent_prtoagonist]

Ok, some back-of-the-envelope calculations:

Kerbin properties:

surface gravity: 9.807m/s^2

GM:

3530 km^3/s^2

radius: 600 km

Eve properties:

surface gravity: 9.807*1.7m/s^2 = 16.66m/s^2

radius: 700km.

assume a 200km orbit to be safely above the atmosphere

Law of Gravity:

g = GM/r^2

=> GM = g*r^2 = (16.66E-3km/s^2)*(700km)^2= 8164 km^3/s^2 for Eve

(as a side note, this means Eve has a mass = 1.223E23 kg, about 2.3x Kerbin)

Circular orbital velocity:

g = v^2/r

=> v = sqrt(g*r) = sqrt(GM/r)

=> At surface:

v_700 = sqrt[(8164 km^3/s^2) / (700km) ] =

3415 m/s

At 200km altitude

v_900 = sqrt[(8164 km^3/s^2) / (900km) ] =

3011 m/s

Gravity drag:

Find an altitude above Kerbin equivalent to 200km above Eve; reaching this altitude should incur the same gravity losses in either case.

specific energy change to go from Eve surface to 200km:

dE = GM/r2-GM/r1 = (8164 km^3/s^2)/(900km) - (8164 km^3/s^2)/(700km) = -2.592 km^2/s^2

equivalent altitude above Kerbin:

r2 = GM/(GM/r1+dE) = (

3530 km^3/s^2) / ((

3530 km^3/s^2)/600km -

2.592 km^2/s^2) =

1073 km

Air drag:

This is a bit trickier. Drag force scales linearly with density, but I'm not sure how that translates into drag losses. Maybe the best way to deal with this is to modify a small part (maybe a parachute) to add the appropriate extra drag for each design.

Oi, that was more complicated than I thought. I'm doing all of this off the top of my head, so feel free to check my numbers, but these seem about right.

So in total, a normal rocket that can launch from Kerbin and reach a speed of ~3000 m/s at an altitude of ~1000km (which would put it in an escape trajectory and then some) should be able to reach low Evonian orbit, not accounding for drag...

[what-the]

How much Delta-v does the EVA pack have? Using it in the calculations for total delta-v could save a lot of weight if you don't mind the risk of losing your Kerbal.

[silent_prtoagonist]

How much Delta-v does the EVA pack have? Using it in the calculations for total delta-v could save a lot of weight if you don't mind the risk of losing your Kerbal.

Haha that's an awesome idea, lob yourself out of the atmosphere on a sub-orbital capsule and then make up the rest with EVA, very kerbal I tried getting a kerbal into orbit from the surface of Mun once, and he fell just a few m/s short of reaching orbit, so they have at least 550m/s dV, and maybe up to 700 or so (I'm not sure how much I lost to gravity drag).

Keep in mind though that you'll need a little in reserve. Even if, once you get him in orbit, the kerbal is the passive member in the rendezvous, he'll still need a little to reach the hatch. Trying to maneuver the ship that close and then switching sounds like somewhere between maddeningly difficult and impossible. Hmm...I feel a challenge coming on

[r_rolo1]

I commmented a link on that video to your Eve I, like hey, your rocket is looking like this guy's rocket! xD

As for a test, because we want to have a ship with extra fuel, I think there should be two tests, one to simulate for far you can take the lander (go into deep space and go into an orbit a bit lower than Eve using a non-optimal flight path (we want to keep it easier) without using any fuel that is supposed to be for landing/takeoff), and the second one is just to get into Kerbin orbit, de-orbit, dump everything but the lander, land with the lander (preferably trying it both with a steep angle and a shallow angle to see how well it can take it), and return to orbit.

And actually, there needs to be a third test, for the return vehicle to get to a bit lower an orbit than Eve, then burn off a bit of fuel, and all it's RCS (I think it should have RCS onboard to make orbital rendezvous easier), then return to Kerbin. Since you already know the proper burn times and places, you should be writing up the guide on how to get there, and I should start flying things and following your guide half-incorrectly (to see how much the design can withstand error and still make it).

.

Well, I do not know the best places to burn I am pretty much eyeballing the issue here , but there are some guides in the "How to" area to get more precise answers ( like here and here ). The basics is quite simple: you want to burn in the lowest orbit possible ( makes the burn more efficient ) and, in the case of wanting to go to interior planets, you want to burn to the inside side of the planet in a way that your trajectory inside the body SoI is hyperbolic ( duh ) and the closest possible to a antiparallel from the orbit the body you're leaving is doing around the center of the system. If you want to train that kind on manouvers you can just do it from the Mun to return to a arbitrary Kerbin orbit ...

[Guard13007]

@Jeebs24 Well you said steps 1-5 and didn't specify that it would be with two ships. Bad wording dude. xD

@silent_prtoagonist Wow. Thanks for the math. I'm a little overwhelmed. xD The only thing I can say about changing drag properties to account for the atmosphere is that it should be scaled on several parts, because else you'd have a really imbalanced rocket in-atmo.

How much Delta-v does the EVA pack have? Using it in the calculations for total delta-v could save a lot of weight if you don't mind the risk of losing your Kerbal.

I read that wrong the first time, as in, who cares about losing the pilot of the lander? xD

Well I replaced the X5's engines with the Eve-simulation ones and gave it a little test. Went up to 2 km, dropped down and landed safely (full burn at 800 meters until chutes open, another full burn at 200 meters until touchdown, which didn't take that much fuel out of the extra tanks).

I managed to get into orbit by taking the idea of throwing the pilot outside. Got into a 82.9 km orbit with 57% pack fuel left, but this does not account for drag, and as silent_prtogonist said, the atmosphere may go much higher up as well. Also, I had to burn off the extra tanks and half of the first set of tanks on the lander to even get off the ground.

Basically, the X5 is pretty close to what we need, but doesn't quite cut it. Or it may be way off, depends on drag, which I really don't know how to deal with.

@what-the I hope we don't have to get out and push to get to orbit, but if we do, hey, we don't litter space with debris cause the ship falls back down. xD

@silent_prtogonist I think if we have to jump out in order to make it, we should have at least 10% pack fuel for final maneuvers. As you say, it is pretty damn hard to do otherwise (although I have seen someone do it! The before-mentioned Scott Manley).

Well, I do not know the best places to burn I am pretty much eyeballing the issue here , but there are some guides in the "How to" area to get more precise answers ( like here and here ). The basics is quite simple: you want to burn in the lowest orbit possible ( makes the burn more efficient ) and, in the case of wanting to go to interior planets, you want to burn to the inside side of the planet in a way that your trajectory inside the body SoI is hyperbolic ( duh ) and the closest possible to a antiparallel from the orbit the body you're leaving is doing around the center of the system. If you want to train that kind on manouvers you can just do it from the Mun to return to a arbitrary Kerbin orbit ...

Oh sorry. It seemed like you did, either way, you're still closer to figuring it out than me. As for the last part about leaving the Mun to a certain orbit, I think I know what you mean, I've done that before (or rather could have, I instead just set myself into falling straight into Kerbin to return).