Lightest Eve Lander

[Red Iron Crown]

Working on my own entry. Landing weight is around 47 tons as you can see, takeoff is about 40. Atmospheric dV just manages to squeak by at 8742, but I brought rover wheels for a reason, I can climb up to the top of a mountain to take off. The vacuum dV is over 10000. I'll post again once I get it to Eve and back.

http://i.imgur.com/FEz4mOL.png

That is one lightweight Eve lander! Would you mind sharing the .craft file?

Here's a thread I created about my mission:

http://forum.kerbalspaceprogram.com/threads/76012-Eve-Manned-Return-Mission

Congrats on the successful mission! You definitely brought more back up to orbit than the rest of us did, every little bit of mass in that final ascent stage means many tons on the surface.

[sdj64]

Alright, finished the mission. I'm surprised how well it performed as a rover, it only broke 5 wheels and I had to quickload 3 times! Not bad for a 45 ton rover in Eve's high gravity (and my reckless driving). Anyway great challenge, this is actually my first stock Eve return. I enjoyed trying out all of the new 23.5 parts in the lifter and the upgraded Ions.

Landing weight: 47.69 tons

Takeoff weight: 40.56 tons

As requested, craft file (Requires KER): http://www./download/hhak574ui4kx71d/EveAndReturn.craft

This includes the launcher and ion return stage.

Some things are not action grouped (namely the solar panels and engines on the ion probe)

Ladders are action group 10 (0).

The science modules are a bit too high for the Kerbal to get the science out of them. As you can see in my picture I had to decouple them (on top of the parachute debris since they would explode if they hit the ground), so if you want to use them you might want to put a ladder on them.

With the flight plan I used there is no debris left in space at the end.

Pictures!

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Edited April 16, 2014 by sdj64

[Nedal]

wow. One I just finished testing is about the same stats. I think mine was 48.8tons with the landing legs on. lil different design philosophy.. but basically same principles as yours. Will do the proofs sometime in next couple days.

[Nedal]

So I was able to land at a nice altitude of around 6500 meters. So the whole amount of stages i brought wasnt required. The lowest i could go from there was with 30.63 tons of launcher. 28 could be possible perhaps with a better ascent profile.. but i didnt quite make it when i tried. I could imagine perhaps a 26ton ship making it from the highest altitude possible.

But my entry is 30.63 at launch.

I dont have any spiffy mods so i made a proof video using the info screen in the map view to show weight.

craft file http://www./view/q49m21ocf4jvcfm/LilEvee.craft

It's got a stupid big launch system attached to it.. cause im impatient with burns.. and wanted lots of dv to pinpoint a landing.

Video. http://youtu.be/VzT_H6EPqcw

Edited April 18, 2014 by Nedal

[GeorgeG]

Here's my entry. It is not quite the lightest for liftoff (31.868 ton). But the ship seems to be the lightest for landing of any others mentioned here.

So, I officially apply for the "lightest at landing" category, at 33.197 ton.

I don't think I can get it any lighter for launch without going to the "flying pancake" extreme asparagus approach.

Coming down on chutes, the mass was 33.418 ton.

It uses 7 chutes (one being a drogue), but does a very short "dab burn" to cushion the landing for the last 10-15 meters.

After that burn and landing, sitting on the ground before jettisoning the "landing stuff", the mass was 33.197 ton. Landing/launch site about 6500 meters.

A small top-off tank was attached to the parachute assembly on top of the vehicle. After transferring fuel from the top-off tank to the lander's tanks to fill them up, the parachute/top-off tank assembly was jettisoned, pushed away by a separatron.

After the jettison, the ready-for-liftoff mass was 31.868 ton

So, the mass at moment of liftoff: 31.868 Ton.

Delta V calculated capability before liftoff: 7672 m/s atmo, 8814 m/s vacuum

Some exploring….

Then back inside and liftoff

Action Groups were used to turn on and off some of the Rockomax 48-7S engines in the upper group of Asparagus tanks. This was done so that when the thrust to weight was more than needed some of those engines could be shut off because their ISP was somewhat poorer than the other engines (LV-T30 and the aerospikes). Shown here, two tank/engine sets just jettisoned, the ship climbing on the last set of Asparagus tanks and the core.

An uncluttered view.

Final stage burn towards orbit.

Stable orbit achieved.

Data after reaching orbit:

Mass .868 Ton

Orbit 100.149 x 99.790 Km

Delta V expended 8478 m/s

Delta V remaining 52 m/s

Ship file is here: http://www./view/xh32o8z8ehk8ttj/Eve_2014_-_6.craft

Stock plus Mechjeb.

As some of you may know, from sometime late fall of 2012 until the April 2013 forum crash, there had been the SEAV challenge. Smallest Eve Ascent Vehicle. I made a number of ships for that, often being the lightest, though they were all ladder-riders. In the SEAV challenge, it was the mass of the ship as it descended towards the ground (the assumption was that a separate stage had been used for de-orbiting, so the starting point was the lander itself falling thru the atmosphere).

- George Gassaway

Edited April 25, 2014 by GeorgeG

[Nao]

I remember the SEAV! It was great fun.

Only 8478m/s expended from 6500m, that's some great piloting. The mass at liftoff is really low too. Great work, my hat's off!

[rtxoff]

GeorgG that is an awesome rockeet.

[GeorgeG]

Thanks for the comments.

Here's a few other images to show other views, launched from KSC.

This one shows the chute/top-off tank assembly on the top.

Close view of all the engines burning.

First set of tanks jettisoned. The landing gear could have been mounted to those tanks, in real life it would be best (I added the legs to the Aerospike tanks before realizing the need for some more fuel, adding the smaller tank set later). There is a bug in the game that gives those aircraft gear legs zero mass (If I'd been very close to being the lightest I'd have done it just to get rid of their "drag" values early). The big steerable fins are definitely needed to be aerodynamically stable and to maintain control due to no vectoring by the Aerospikes and T-30 engine).

The ship after jettisoning the outer Aerospike tank set.

After dropping the lower core with its LV-T30 engine, firing seven Rockomax 48-7S engines. For the test flight from Kerbin, it had enough Delta-V left (3830) to fly to the Mun or Minmus (no legs though) and back, and soft land at KSC.

I had used the Eve ascent profile for the Kerbin test. For a more optimal Kerbin launch, I reflew it to a 72 km orbit, it had 4154 m/s left over. For the heck of it, I had added landing legs to the last two outer tanks. Landed it on the Mun with 2399 m/s left. Flew back to Kerbin, and soft landed at KSC with 529 m/s left.

Edit - pic of the above described Mun-landing version.

- George Gassaway

Edited April 26, 2014 by GeorgeG

[GeorgeG]

OK, so I got out the hacksaw, hammer, screwdriver, crowbar, sandpaper, and a new slide rule. Thunked, tweaked, swapped parts, fiddled, cogitated, and buffed and got a lighter ship to make Eve orbit.

So now I'm making an official claim for lightest at launch with a liftoff mass of 30.407 ton.

I figure if Nedal does some similar tweaking with his, he'll be able to beat it.

A descent mass of 31.957 ton before landing.

After landing, 31.639 ton (some fuel used to cushion the landing, as before). An EVA before preparing to lift off.

After jettisoning the chute and top-off tank assembly, ready-for-liftoff mass of 30.407 ton.

A good liftoff, shown here is the ship after jettisoning the lower sets of tanks/engines.

And…. in orbit.

Orbital data:

101 km x 98.7 km

Delta V remaining: 22 m/s

Delta V expended: 8577 m/s

Vessel mass: .861 ton

craft file: http://www./view/xqc4qnadjo9xjsd/Eve_2014_-_9.craft

Action groups for this ship and the previous one are:

1 - ladders toggle

2 - engine toggle on twin engine upper tank pair

3 - engine toggle on the single engine upper tank pair

5 - all chutes deploy (drogue opens at 2500, two at 1200, final four at 500 meters).

9 - jettison of the chute/top-off tank assembly

- George Gassaway

Edited April 26, 2014 by GeorgeG

[Nao]

So now I'm making an official claim for lightest at launch with a liftoff mass of 30.407 ton.

Beaten by 71kg and in 2 stages less hehe

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The ship has 202m/s dV in orbit and with some tweaking could break below 29t at launch, ill wait for others to submit before repeating the flight. Cheers!

Edit: sorted out the album link... Is there way to pick what image will be displayed on page load when using the "[ imgur ]" code?

Edited April 26, 2014 by Nao

[GeorgeG]

Great job Nao.

The latest ship I showed, it had been a bit lighter (than yours) but kept coming up short of a stable orbit by about 10-15 m/s. So I ended up adding one more tiny 1/2 meter tank to the final stage.

So, that's probably it for me.

- George Gassaway

Edited April 26, 2014 by GeorgeG

[Nao]

Tried your rocket, and really liked the drop tank, very well vectored thrust.

Only managed 106x81km orbit with it(too ascent shallow, as usual for me) hahaha

Wonder if switching the type of engines around, with LV-T30 (two) staged before aerospike (one) (and rebalancing fuel per stage to match TWR) could bring benefits. The LV-T30 and aerospike are pretty evenly matched on eve but the spike wins in longer runs.

Also, did get some MJ glitches? My current TWR kept changing randomly between ~2.6 and ~1.8, so im wondering if its bug on my side or in MJ...

e: Ahh, and what happened to your account? There is no way you could have 20posts by now

[Red Iron Crown]

Great designs, Nao and GeorgeG. Who can break the 30-ton barrier first?

[Nao]

Great designs, Nao and GeorgeG. Who can break the 30-ton barrier first?

"OK" !

>>cue Danger Zone<<

Tom "Kruise" Kerman, starring in Top Eve

Launch mass 28t and 15kg

Twr 0.81 "I'm off!!"

"Maverick where are you? I'm in space Ice!"

(I know i bended the rules a little, but this is just technology demonstrator... it's possible to make it better. (it's actually much better starting from lower atmosphere, I've already tried versions above 100t liftoff mass with some success.) e: added one more picture

Edited April 26, 2014 by Nao

[GeorgeG]

Tried your rocket, and really liked the drop tank, very well vectored thrust.

Only managed 106x81km orbit with it(too ascent shallow, as usual for me) hahaha

Wonder if switching the type of engines around, with LV-T30 (two) staged before aerospike (one) (and rebalancing fuel per stage to match TWR) could bring benefits. The LV-T30 and aerospike are pretty evenly matched on eve but the spike wins in longer runs.

Also, did get some MJ glitches? My current TWR kept changing randomly between ~2.6 and ~1.8, so im wondering if its bug on my side or in MJ...

e: Ahh, and what happened to your account? There is no way you could have 20posts by now

Thanks, glad you liked it. As I mentioned, it also is an interesting ship to fly to the Mun and back, just adding 4 legs to the last two outer tanks.

Really nice winged Eve rocket.

Yes, technically I only have 20 posts (Well, 21 with this one). When the forum crashed a year ago it wiped out all of my messages (I had made hundreds). Including the loss of my massive mission reports to Eeloo, Moho, and Eve/Gilly, which many people liked. It really depressed me to have all that lost. And also about then I needed to stop playing to concentrate on other things for the summer. I've posted a little bit but not a lot. Also only played a little bit in December and this past week. And now I have the summer stuff to get ready for again.

BTW - Saturday, I attended Air Space Minnesota's "Go Boldly" exposition. Four astronauts were in attendance:

Buzz Aldrin - Gemini 12, Apollo 11

Karen Nyberg - Two ISS missions, one aboard STS - 124 in 2008, and one aboard a Soyuz in 2013

Harrison "Jack" Schmdt - Apollo 17

Curtis Brown - Flew 6 shuttle missions, 3 as commander, including STS-95 that John Glenn flew on.

Aldrin, Nyberg, and Schmidt had talks and presentations.

- George Gassaway

[GeorgeG]

Well, like the strong gravity of Eve, I could not resist the pull to make one more shot.

Liftoff mass of 28.022 ton

A key part of the improvement was using the 7.5 km site that Nao used for his winged vehicle. It is sloped enough that I had to extend the footprint of the legs to keep it from falling over (though it fell a few times before getting a good landing).

And I swapped out the T30 from middle to outer, and aerospike from outer to middle, as Nao suggested.

Also did some other tweaking of tanks.

Mass at landing 29.177 ton, chute and top-off tank assembly still on.

EVA

Mass at liftoff 28.022 ton

Jettison of first tank pair with legs.

In orbit.

Orbital info:

100.26 km x 100.09 km orbit

8218 Delta V used

37 m/s Delta V remaining

Ship file: http://www./view/tb7ey2vov7sz76t/Eve_2014_-_12-3.craft

- George Gassaway

[bhauth]

Challenge says a minimum of 8700 ∆V, GeorgeG. :-)

Here's a craft, <26.5t without landing stuff, that should work if anyone wants to fly it. Double tap 1 to steer.

www.bhauth.com/files/eve_lander_challenge.zip

[Red Iron Crown]

Challenge says a minimum of 8700 ∆V, GeorgeG. :-)

Here's a craft, <26.5t without landing stuff, that should work if anyone wants to fly it. Double tap 1 to steer.

www.bhauth.com/files/eve_lander_challenge.zip

Got any pics?

[bhauth]

Hmm, probably tomorrow.

Edited May 3, 2014 by bhauth

[GeorgeG]

Challenge says a minimum of 8700 ∆V, GeorgeG. :-)

Hmm, I have to wonder.... why did the OP do that?

Might as well be a challenge just to make the lightest rocket that has a Delta V of 8700, forget orbiting Eve.

I had tweaked out my rocket more, getting it to something like 27.3 ton.

But I guess it's not worth posting it or anything else. I'm not going to screw around with rockets that have far more Delta V than they need to accomplish the task of making orbit.

Also not going to screw around downloading craft files blindly. I have to DL on my laptop, transfer by thumb drive to the one I play KSP on, which I do not have access to as easily as my laptop. Too much hassle to go thru for something that I don't know beforehand if it's something that I would have wanted to DL and try out.

- George Gassaway

[Nao]

...BTW - Saturday, I attended Air Space Minnesota's "Go Boldly" exposition. Four astronauts were in attendance...

Ah, that forum crash was really unfortunate indeed

The exposition thou, meeting with astronauts irl is really cool, especially with both old and new generation I'm jelly.

Here's a craft, <26.5t without landing stuff, that should work if anyone wants to fly it. Double tap 1 to steer.

www.bhauth.com/files/eve_lander_challenge.zip

The ride was as you would expect, rough . Tried taking off from 6500m flat area, was short 950m/s off orbit

Still some of that craft concepts are great, although i did not use double tapping 1 but tweaked engine power mid flight, (this made unbalanced fuel load at 3rd stage from top thou). Still it was a fun idea!

Well, like the strong gravity of Eve, I could not resist the pull to make one more shot.

Liftoff mass of 28.022 ton

Nice work! Although i think you have a little too much thrust there. But i know how hard is to divide the thrust with bigger engines... that said our friend bhauth here had none of it with hilarious results.

Hmm, I have to wonder.... why did the OP do that?

Landing precisely at that 7500m point is *very* difficult with parachutes in normal mission. Even landing at that flat spot of 6500m nearby is quite tricky. I guess he wanted something that could be actually used.

In the mean time I went on ahead and improved on the plane lander.

25.805 t before takeoff, 8815m/s deltaV, 7536m start height. Finished with 93m/s left in 100.5x101.5 km orbit (848kg final mass)

And this is the extension of the above craft with top drop tanks, it can ascend from 5000+m and weights only 35,035kg (MJ is wrong in VAB) (since the OP really wanted to have a more versatile Eve ascent vehicle)

I really love rocket planes on eve, much safer landings, as it's possible to cherry pick a spot, including mountains. And its really easy to add detachable rover wheels and just drive from sea level landing to some sufficient high mountain to ascent from.

The wings on top of the droptanks are there more as a balancer to thrust not pointing on the CoM. Its very well possible to install them on the sides without any wings, and still have normal flight characteristics.

Since i'm lazy both ships have MJ module installed.

http://www./download/5ejlw8db958l9w8/ (The first ascent vehicle - VAB)

http://www./download/96uate8ebaibegx/ (The plane with droptanks - SPH)

Edited April 28, 2014 by Nao

[bhauth]

Also not going to screw around downloading craft files blindly.

Yes, fine, here's a picture.

http://i.imgur.com/S8HKnph.jpg

Ah, so beautiful. I am an artiste.

The ride was as you would expect, rough . Tried taking off from 6500m flat area, was short 950m/s off orbit

Still some of that craft concepts are great, although i did not use double tapping 1 but tweaked engine power mid flight, (this made unbalanced fuel load at 3rd stage from top thou). Still it was a fun idea!

It didn't make it? Noooooo!!! Do you think it could, with perfect piloting?

Landing precisely at that 7500m point is *very* difficult with parachutes in normal mission. Even landing at that flat spot of 6500m nearby is quite tricky. I guess he wanted something that could be actually used.

Yeah, I think takeoff from <=6500m should have been the challenge. (That disqualifies your plane, of course...) Is a plane still lighter if not going for a ∆V requirement?

[Red Iron Crown]

Yes, fine, here's a picture.

http://i.imgur.com/S8HKnph.jpg

Ah, so beautiful. I am an artiste.

That makes my rocket symmetry OCD twitch uncontrollably. Did you manage to get it into orbit from Eve?

[EdFred]

Yeah, but what about the lightest one departing from less than 500m elevation?

[rtxoff]

Nao, with that many control surfaces your craft is considered using the infiglide exploit....