EVE_M (madness).. the first cpu-friendly eve-return design! (+howto fly)

[SpaceGibsy]

The requirements were:

- get to eve and back with a few liters Spare in each Stage.

- use as few engines as possible to both cpufriendly and efficient

- look kerbal (added by jeb)

- less than 500t

This 437t rocket was designed and build like this. The engineers designed almost perfect stages from LKO to Eve and back. Then they were struggeling how to get these into orbit.. they already figured out that it had to be 4 BIG engines. It was a few hours before the next startingwindow so jeb became nervous. He came into the lab screaming "IT CANT BE THAT HARD TO BUILD 4 F*** BOASTERS! ILL DO IT!"

Leaving the engineers already thinking about his gravestone (and how to deliver that one) - his design has prooven both functional and kerbal - kerfect!

I want many people to achieve this great goal so here comes the detailed "How to Fly":

1. Wait for the right time to start, eve has to be in ~51° behind kerbin:

2. Takeoff! Gravityturn should be around 13000 meters.

3. As soon as the last tank of the last boosters are used drop the remaining 2 big Engines.

4. You should end in orbit still having plenty of fuel in the big bag!

5. Slightly after the edge of sunrise fire your engines. The bag should be enugh to get you on a collision course to Eve. It has some spare liters for inclanationchanges to. As soon as you see a "desired periapsis" on eve try burning in any direction that lowers this desired periapsis the fastest. Like this you can get a collisioncourse using only a few liters to aim.

6. (optional) Pros can use the Mun to save fuel by a swingby manouver..

7. Once your in the influence range of Eve drop the bag. You should go to the orbial view and focus Eve use (TAB) to find out where you would hit the ground. Thats neccesary to land on the highest mountain on Eve as the atmosphere is already <1atm and the drag is Kerbin-like. If the mountain happens to be on the wrong side just retro/pro-burn a little. since you're still serveral days away that will change the orientation completly when you hit the ground. Attitional aiming should be done by burning 90° relative to proburn. With a little try and error you should hit the desired landingspot +-~3km using almost no fuel.

8. Landing is done powered using the rest of that stages fuel. Only burn below 12,600meters as there is no fuel to hover and stuff. you may savely use 500liters of the next stage to.

9. After landing drop the empty fuel to make room for the ladders. If you happen to have a rover 1.4km away like me go there and have fun for the next ~150 days.

10. Anyways..

11. Once Kerbin is ~36° in front of you leave Eve. The gravityturn should be 24km bringing the last stage with at least 230units fuel to a stable orbit.

12. DO NOT burn yourself to kerbin like the calculator is telling you! Since your orbit is inclined a lot due to the non-equator landingspot it may help to even burn 10° before the nightside. That takes less fuel than correcting 11° of inclination later. After a few trys i managed to get a Transferorbit with only 2° of inclination. A little more aiming and you are ready to hit kerbin.

14. Now let jeb take care of the nuklear waste - leaving it in space. I still had 20units of fuel left so aiming for KSC would have been easy, but after such a long time even jeb was homesick. "I.. WANT.. HOME.."

15. If you already punched your chute right now your doomed. As we are approaching veeeery fast the atmosphere will rip that thing appart in no time. You will have to wait until you've lost most of you speed.

Get the ship here:

http://teatime.nerdbox.de/downloads/kerbal/eve_return/EVE_M.craft

Edited October 18, 2012 by sal_vager

[sjwt]

Well done, you've beaten me =>

[Wayfare]

Bravo, sir - bravo!

[r_rolo1]

Looks nice

Without seeing the .craft file ...

a) Do you really need the nuke engine? As far as I can deduce from the pics, the aerospikes do most of the work on the landing stage up to ev and the nuke engine only works solo in the return. Eye-balling the issue the nuke engine alone weights almost a third of the return ship even when the tanks are full so it wouldn't have been more economical to use a LV-909 ?

Using chutes could had helped with the Eve landing fuel wise? Again eye-balling things but 6 small chutes could probably make you to not use any fuel at all to land ...

[SpaceGibsy]

thanks ..

a) That nuke engine is neccesary for several reasons. even with 2.25 tonns it provides way more dV than a lv909 of the same weight and even that extra 10KN of thrust are neccesary to escape eve.. (that last stage ist burning since eve/50000m/1500ms..) i just dont have much time to get to orbital velocity. every lv909 attemt ended with way more than 4000m/s loss when leaving.

I have designes with a nuke + one fuel tank. and 4*3 tanks instead of 4*3.5.. thats most likely able to reach kerbin (i missed it once just 700.000km). that would be an option. the whole design might be possible with <350 tonns

i've tryed chutes.. but they dont work as well as you might think in 11k+ altitude.. i would need ~20-30 to land without powering in that altitude. bringing 3-4 tonns of fuel for a powered landing is just way more easy than placing 3 tons of chutes.

[melaus]

congrats SpaceGibsy,

I have to be honest, I didn't think that ship design could do it without some adjustments. Landing on eve with chutes isn't about making a powerless landing, its about decreasing the fuel used to land. they also have a diminishing rate of return in terms of using lots to slowing you down even more, so a powerless landing might not even be possible. chutes weight a fraction of a ton, while the fuel used to land usually ends up being far more than that.

and yes R_rolo1, you're better off with the nuke engine (even with the weight) than with an aerospike, by the time you're on the last stage, if you're not in space or near space with a good enough velocity, you've probably failed anyway. trust me, i've tried.

Edited October 10, 2012 by melaus

[SpaceGibsy]

i tryed again with some chutes - and jet managed to save another ton.. stay tuned for the 3-booster version,.. with way less than 400 tonns :-)

[sjwt]

Fantastic job, I was up late last night working on my version of a Eve lander and return.. I've not got time to make it look nice and check it dose do the trip <G> cant get the transfers right, even with mods.. :<

[Tommygun]

Great job SpaceGibsy, would you mind listing the map coordinates of that mountain?

I have been looking at three possible mountains and I think that is one of them.

[SpaceGibsy]

@sjwt: If its the transfer home that struggles you? Try burning your way home several degrees before the nightside.. that happend to kill a lot of inclination..

@Tommy: i dont know the actual coordinates .. its the only one with a white dot on this map http://kspwiki.nexisonline.net/w/images/e/ed/Eve_isa_mapsat.png .. in the south west of the "ring". the 11k+ area is ~ 20km wide.. but it helps a lot to hit the exact top! I'd suggest to put a rover there in the first place - it helps a lot when you're landing!

[EvilotionCR2]

It look like my Eve back design...Anyway,good job!

[sjwt]

@sjwt: If its the transfer home that struggles you? Try burning your way home several degrees before the nightside.. that happend to kill a lot of inclination..

Its the transfer to any planet im still working on =>

[Tommygun]

@Tommy: i dont know the actual coordinates .. its the only one with a white dot on this map http://kspwiki.nexisonline.net/w/images/e/ed/Eve_isa_mapsat.png .. in the south west of the "ring". the 11k+ area is ~ 20km wide.. but it helps a lot to hit the exact top! I'd suggest to put a rover there in the first place - it helps a lot when you're landing!

Yes that one was my first choice of the three mountains.

I was able to get the highest elevation off of one of my map scans as 11,799.3 meters at Longitude -88.91 ; Latitude -12.12 .

That would put it in the location in the South West.

Thanks.

[RealHogweed]

+rep for you, you deserve it.

[Millitron]

You could've done the launch a little more efficiently. Since we're transferring to a planet in a lower orbit, your Kerbin parking orbit should have a heading of 270 for best efficiency. Your launch will lose about 170m/s deltaV, but your transfer will be significantly cheaper.

[Maxed-Rockets]

You could've done the launch a little more efficiently. Since we're transferring to a planet in a lower orbit, your Kerbin parking orbit should have a heading of 270 for best efficiency. Your launch will lose about 170m/s deltaV, but your transfer will be significantly cheaper.

No, it is always better to go for a 90 degree orbit, you lose about 340m/s of DV because you have to overcome and make up for the rotation of the planet. It goes like this.