Single Launch to Eve and return Challenge

[Red Iron Crown]

That would be interesting to see how he lands safely on Kerbin. Or even leaves Eve's SOI.

I think he means to complete getting into orbit with the jetpack, then rendezvous with the return craft.

Or maybe not. I'll just leave this here (not mine, but funny and awesome).

[Nao]

Sooo....

"Year 4 Day 140 Arrive back on Kerbin before this date, and add 5 points per day, deduct 5 for every day afterwards."

If i launch at Y1 day1 (using 2200m/s dV transfer) land on eve around day 125 and launch immediately for a (3400m/s transfer) to arrive on kerbin at Y1 day 418, that's worth 5000 points.

Now Kerbin -> Eve transfer will take ~1200m/s more than optimal but by using nuclear engines it's not that big of a number

And Eve -> Kerbin the ship will be super light so the ~1600m/s more dV will not be a problem (assuming we left "command module" with nuclear engines in orbit to dock, apollo style). With properly build ship i wouldn't be surprised if somebody managed below 300d trip from day1 of sandbox.

Is this intentional? Because this transforms the challenge from ascent from near eve surface on minimal cost, to who can do the trip fastest. The tremendous gain in points from speed, also trumps any disadvantages like part count and mass making this a "who has better PC to launch ridiculously big ship" challenge. (I'm not really complaining thou, just rising the issue.)

[Red Iron Crown]

^^ That was my analysis of the scenario after playing with alexmoon's calculator. I've got the ion-powered return stage for a high energy return transfer put together already. The mass and part count scoring pales compared to the early completion scoring.

[EdFred]

Sooo....

"Year 4 Day 140 Arrive back on Kerbin before this date, and add 5 points per day, deduct 5 for every day afterwards."

If i launch at Y1 day1 (using 2200m/s dV transfer) land on eve around day 125 and launch immediately for a (3400m/s transfer) to arrive on kerbin at Y1 day 418, that's worth 5000 points.

Now Kerbin -> Eve transfer will take ~1200m/s more than optimal but by using nuclear engines it's not that big of a number

And Eve -> Kerbin the ship will be super light so the ~1600m/s more dV will not be a problem (assuming we left "command module" with nuclear engines in orbit to dock, apollo style). With properly build ship i wouldn't be surprised if somebody managed below 300d trip from day1 of sandbox.

Is this intentional? Because this transforms the challenge from ascent from near eve surface on minimal cost, to who can do the trip fastest. The tremendous gain in points from speed, also trumps any disadvantages like part count and mass making this a "who has better PC to launch ridiculously big ship" challenge. (I'm not really complaining thou, just rising the issue.)

That was unintentional, I wrote that part before I realized how much time you could save while not waiting for Eve to come around. When I had a high dV burn like that with nukes going to Jool, my burn time was longer than an orbit around Kerbin. Unless of course, you were planning on putting 60 nukes to work. I may have to cap the max points on that, or toss it completely. I was thinking more along the lines of getting a perfect aerobrake so you didn't waste time making repeated aerobrakes around Eve.

[Red Iron Crown]

Nuts, I figured with my 5 point head start I was a shoe in.

Still interested, though, I haven't done Eve in a single launch before.

[EdFred]

After further review the time frame aspect has been removed. Sorry guys, I didn't realize it would skew the results that badly.

[Emod]

Hi guys, I'm new here, almost.

Two weeks ago I was tinkering with an Eve lander and return craft just for fun, and realized now it might fit in this challenge.

I call it "Eve concept v2". 1656 tons at liftoff with 489 parts. Mechjeb and kerbal alarm clock used. (Also the chatterer and some cloud mods are used but those shouldn't affect gamleplay.)

Lander works fine from sea level, and has a rover for Jeb's pleasure.

However, I *really* should go to bed now, so if I'm not disqualified I'll do the point count tomorrow. ok? I'll try to post some pictures:

At liftoff.

Goodbye kerbin

At Eve. Detaching lander from "the pig". Lander tanks are very big just to land at places that are far from where the orbit goes. Rest of ship will remain in orbit.

Down we go. The small chute is the rover. Will we land on land or sea????

Both, hahahaha!! Lander weight is 124 tons with rover I think.

Flag is there. My almost first try to make a nice rover, and it performs very well.

Liftoff.

Rendezvous with the main ship. Lander har 250 dV left at 100km, but main ship (aka "the pig") has a lot more, so the pig will do the manuevers.

Then I didn't want to wait one year for a launch window so I just hit the throttle and came back a lot faster via, almost, duna.

Made it back, aerobraked, and aimed for the space center. Then I realized the ship had more than 1 in TWR, so I (or mechjeb) just landed the pig as it was. I could have saved the chutes...

/Emod

Edited May 7, 2014 by Emod
Stupid DynDNS closed my account..

[Red Iron Crown]

^^ That's a great ship and mission. And welcome to the forums!

Edit: Where did that post go?

Edit again: It's back!

Edited May 7, 2014 by Red Iron Crown

[Emod]

Thanks! I had quite fun doing it.

Here's the craft file : http://kasplutt.dlinkddns.com/L/Eve_concept_v2.craft

(I hope link works. I had a server mess when DynDNS closed my account and I had to get a new one. I hope the images in my last post works too after editing..)

As for ponts count:

1000

-

5*20 for stages =-100

-

6*10 for engines =-60

-

48,9 for parts

+ 250 for land at 0 m

- 165,6 for weight

Should be 875.5!

[Emod]

Posts has to be checked by an admin for some reason?! If edited they disappear until it's done

[EdFred]

Nice score. I updated the leaderboard.

I'm going suicidal with mine. No chutes to return to Kerbin. Why? Not going to refuel or dock when departing Eve, and the chute costs me 400 dV on ascent.

Edited May 7, 2014 by EdFred

[Red Iron Crown]

Posts has to be checked by an admin for some reason?! If edited they disappear until it's done

I think that's an anti-spam measure, it goes away after 5 posts IIRC.

I'm going suicidal with mine. No chutes to return to Kerbin. Why? Not going to refuel or dock when departing Eve, and the chute costs me 400 dV on ascent.

Your own rules specify that all kerbals must return alive to the surface of Kerbin...

Edited May 8, 2014 by Red Iron Crown

[EdFred]

Starting: 1000pts

15 stages: -75pts

4 engine types beyond 1: -40

Part count: 299 parts = -29.9

Elevation: 19m: +240.5

(impact prediction showed 2m, but it came up just a bit short of the shoreline)

Weight at KSC: -212.7165

Extra Kerbals: +0

Total: 882.8835

Screenshots to follow.

Edited May 8, 2014 by EdFred
forgot my part count.

[Emod]

yes, screenshots and craft file please

[EdFred]

http://www.sidnaw.org/kerbal/EveChallenge.htm

Trip documentation and craft file.

Note that the craft file contains MechJeb and KER. So if it won't load, you may have to go into the craft file and remove those parts.

[Emod]

Nice, I tested it and works fine. Nice thinking of not using any lander legs..!

Still, I'd like 10 additional style points for bringing a rover. Please?

[EdFred]

I've actually been to Eve's surface and made it back to orbit a few times with a few different landers. I tried landing legs - and no matter how many I put on, they got wobbly and broke. I tried girders, I tried plates. Nothing seemed to work. Then I noticed the crash tolerance of 20m/s, and I decided to give that a whirl. Is the lander a bit heavy? Sure. But it gives a great initial punch to get off the surface. Tell ya what, I'll give you 10 style points for the rover, if I can give myself 10 for not using parachutes on the return home.

[Emod]

Thanks! More points for everybody

I tried to land in water (or whatever it is) with the LFB KR-1x2 you are using, but they desintegrate at contact while running, so wet landings are not recommended.

Seems like lander legs got weaker when suspension was added. Locking suspension doesn't help either.

If you have tested the mighty Eve Explorer http://kerbalspaceprogram.com/eve_explorer-mj/ recently you'll notice It cant land anymore without crashing because of the legs.

Competition seems a little sparse here, so I've tested the other two Eve can-landers I know. Eve explorer by Steven Lawyer (his youtube video well worth a watch) and Leviathan-17 by Igor Sikorsky. I couldn't find a link to his ship atm, but could be downloaded from some Russian site. Maybe you can add them to your list, just for fun?

Both are sea level landers (assuming 0 m), and I didn't cound the payload (Rover & plane) engines. Also, these were created long before the ARM parts so they're pretty heavy, and not at all optimized for this contest.

Eve Explorer:

2330 parts 88 stages 4430 ton. 2 man lander (also with 4+1 rovers)

1000-

-233 (parts) -440 (stages) -443 (weight) -20 (engines) +150 (sea level) +125 (+1 kerbal)

Should be: 139

Leviathan-17:

1065 parts 36 stages 3085 ton. 1 man lander (Also with a rover AND a plane)

1000-

-106.5 (parts) -180 (stages) -308.5 (weight) -20 (engines) +150 (sea level)

Should be 535.

[Morlock]

Pure Rockets

1000pts

16 stages beyond 0: -80pts

3 different engine models: (3-1)*10 = -20pts

Part count: 578 parts/10 = -57.8pts

Elevation: 3.6m (500-3.6)/10 * 5 = +248.2pts

Weight at KSC departure 1266.28t /10 = -126.628pts

--------------------

Total: 963.772 overall pts

https://www.dropbox.com/s/asybim97savavgk/DL-1.craft

Edited May 20, 2014 by Morlock

[EdFred]

Well done. I didn't think it was going to make it. You could have went even lighter. I downloaded your craft file and still had around 1/2 tanks in the ones that jettison on the Eve descent. (I only intercepted Eve, and didn't make a plane adjustment.)

[Morlock]

Thanks!

I didn't make a plane adjustment, I did a aerobraking and then a circular orbit. This consumes some fuel, but if not how can I fix the coordinates of the landing ?

[EdFred]

Thanks!

I didn't make a plane adjustment, I did a aerobraking and then a circular orbit. This consumes some fuel, but if not how can I fix the coordinates of the landing ?

What I did with your craft was aerobrake a couple times, but still keeping a fairly eccentric orbit and then decoupled the orbiter from the lander. Keeping the apoapsis relatively high, it takes very little to move the periapsis for either craft. Maybe 5dV to move the periapsis to 100km on the orbiter, and less than 5dV to tweak the landing spot.

Turn landing guidance and predicted landings on with MechJeb, tweak at apoapsis and wait till the final 1000m to deploy chutes. (Don't enable the autoland though).

Circularize the orbiter on its own with another aerobrake after the landing using the landing guidance. You can circularize for less than 50dV.

Edited May 21, 2014 by EdFred

[Morlock]

What I did with your craft was aerobrake a couple times, but still keeping a fairly eccentric orbit and then decoupled the orbiter from the lander. Keeping the apoapsis relatively high, it takes very little to move the periapsis for either craft. Maybe 5dV to move the periapsis to 100km on the orbiter, and less than 5dV to tweak the landing spot.

Turn landing guidance and predicted landings on with MechJeb, tweak at apoapsis and wait till the final 1000m to deploy chutes. (Don't enable the autoland though).

Circularize the orbiter on its own with another aerobrake after the landing using the landing guidance. You can circularize for less than 50dV.

It is a good tip, thanks. I'll have to further reduce mass.

[Emod]

Yes that was a very nice one! Also using stack instead of radial decouplers on the lander's final stages were brilliant.

Anyone more than me who has noticed that mechjebs "Land at target" and "Land anywhere" use two different techniques? The first make one efficent "sucidal brake", while the latter brakes more gently, even when chutes open, making it as a whole look beter but needs a lot more fuel. The latter also goofs up when not all engines are engaged or when TWR is so high the lander will go upwards when braking for chutes (and therefore cut the chutes).

Yea, yea, wrong forum, I know..

[Damaske]

Going to make something for this But I am going to use Lack Luster labs parts for the main bits BUT WILL USE STOCK ENGINES to power my craft. To clarify You CAN have a lander land on Eve and then redock back with the mothership provided the lander goes back to Kerban? Or can it be deorbited to crash on eve and the mothership return to Kerban? I have an interesting setup in mind but need to know if the lander is allowed to be separate, if it can does it have to return or can it be ditched.

Also Can you have more than one launch and dock together the mothership in orbit before taking off provided you count the stages form EACH separate launch? If so I can attempt another mothership design I have floating aboot my head.