Every planet's surface sample in 1 go.

[Zhetaan]

2 hours ago, NicholaiRen said:

Actually, I was thinking of using planes for Eve and Laythe(still not sure, but Laythe has a thick atmosphere right?), and then a special type of space plane for the others.

For the special space plane. I want to use a reaction wheel, and RCS thrusters, to allow me to land on planets with virtually no atmosphere. When I need to slow down, I'll burn retrograde, and when I need to land I'll use RCS Thrusters to keep me up right when I land. And then if I can figure out how to use mining equipment(I just got them) then I'll try to find a way to refuel the space plane so I can refuel the rocket.

 

Basically, I think space planes are much more advanced and cost efficient then landers. Plus, I absolutely despise landers. I don't know why. I just hate them. It's probably how I design them tough.

Planes are not cost-efficient if you use them on airless bodies; the wings are pointless weight in that case.  Whether a plane is advanced depends on the parts you put in them ... but not on whether they have wings.  However, if you hate landers, then go for it; there's no reason to use a vehicle you don't like.

You can fly planes on Eve, and they actually fly quite well (it's easy to fly when the air is almost thick enough to walk on), but you will absolutely want to test designs before the real mission.  Some engines shiver and die at Eve sea level, and in any case, when you come back to orbit--whether or not you try to do it in a single stage--you will almost certainly want to start from above 6,000 m.  Wings on a spaceplane are dead weight below that altitude, and Eve takes the concept of dead weight literally.

Laythe has a thick atmosphere, but it is thinner than Kerbin's atmosphere at .6 atm.  Many planes for Kerbin work at Laythe, but you usually want to tweak the wing area up a bit if you want an efficient plane.  However, the reason you often get away with less is because although the air pressure is less, the gravity (.8 g) and atmosphere height (50 km) are less, as well.  This means that you need more from the engine to push you up because you're getting less lift with the wings, but the wings have less weight to lift and don't need to lift so far, so it evens out.  Adding more wing gives you far better performance because you can get a lot more lift, and you get to keep the benefits of lower gravity and atmosphere height, too.

You may want to use Vernors for your RCS for both the power and the fact that it uses the same fuel as your main rockets.  They're twelve times more powerful than the quad block and six times more powerful than the linear thruster.  You shouldn't need them to keep you upright, though; planes use horizontal take-off, so why not come in horizontally?  That works for regular airless landing, too; here's a video:

I had an archaeologist dig this video out of some pre-K-T strata (@Kosmo-not and pre-procedural Mun craters!  Ah, the memories....) but the concept is still good.  Learn to land like that and it won't matter whether you're using something with wings, but it will make things much easier if you're using something with landing gear, because you won't need to do the pitchover manoeuvre at the end.

Edited September 15, 2017 by Zhetaan

[AeroGav]

18 minutes ago, Zhetaan said:

Planes are not cost-efficient if you use them on airless bodies; the wings are pointless weight in that case.  Whether a plane is advanced depends on the parts you put in them ... but not on whether they have wings.  However, if you hate landers, then go for it; there's no reason to use a vehicle you don't like.

A plane is much heavier than a lander so will use more fuel on an airless body...  but somewhere like pol or val, that doesn't matter much, especially if you are mining your fuel anyway.  My spaceplanes are usually nuclear powered which makes me want to figure a way to have them push the mothership - no sense carrying NERVs that aren't moving the mothership right?

[AeroGav]

1 hour ago, AeroGav said:

My spaceplanes are usually nuclear powered which makes me want to figure a way to have them push the mothership - no sense carrying NERVs that aren't moving the mothership right?

OK,  I've had a look at this myself.    Here's what I came up with for my Starsailor ISRU SSTO, which has 4600dV and 0.3 TWR on nukes -

https://kerbalx.com/AeroGav/Starsailor-motherdock

So,  the idea is you'd separate this contraption at the docking port,  launch the spaceplane separately,  then the other half of this contraption goes on one end of your mothership.  Now the spaceplane can dock with the mothership and be in line with its centre of mass, and help to push it.

[Zhetaan]

Is there a specific reason you chose to use all of that steel bar rather than put a shielded port on the nose?  Docking ports that already line up with the centre of mass wouldn't require those guide bars, for example, and the fact that you're using nukes at .3 TWR means that even if the misalignment is slight, the length of the burn combined with the lever arm of the plane on the rest of the vessel lets the error build up substantially.

[Spricigo]

10 hours ago, AeroGav said:

 - no sense carrying NERVs that aren't moving the mothership right?

Right,  carrying anything you don't use is a waste.   (Of course I know that you use the nervs at some point. I suppose you get what I mean)

12 hours ago, NicholaiRen said:

Actually, I was thinking of using planes for Eve and Laythe(still not sure, but Laythe has a thick atmosphere right?), and then a special type of space plane for the others.

...

Basically, I think space planes are much more advanced and cost efficient then landers. Plus, I absolutely despise landers. I don't know why. I just hate them. It's probably how I design them tough.

Can't argue with taste, if that is the decisive factor for you just go with what you heart asks for. But...

That impresion that planes are superior to more traditional spacecraft often appears. I have no qualms to say: not at all. Those are just different tools that are better suited for different tasks. A hammer is not a bad tool because it don't cut, a lander is not a bad tool because it don't glide.

Also that impression most often arise from a misunderstanding of the limitations and, worse yet,  advantages of winged designs. Let me explain:

For any spacecraft, winged or not,  weight is a hindrance (often referred as the ultimate cost). All else being equal a winged design will be heavier and, thus, less capable. To make things worse for the winged craft they also have more trouble with drag so even less capable (everything else being equal). 

In any case, while subestimating the limitations of winged crafts happens, overestimating its advantages are by far more common (and I risk to say, more nocive).

One common misconception is to consider lift as some kind of magical force that push the winged craft up 'for free'. In fact what happens (simplified for the sake of this discussion. Technically incorrect but close enough for the relevant point there*)  is that wings 'redirects' some forward momentum to upward momentum , the problems are: that [edit]1.wings always produce some drag(resistance) associated with that lifft (useful force)[/edit]2.only a fraction of the forward momentum will be directed upward. 

At this point (if you accepted what I said so far**) you may ask what advantages wings really offer. 1st) better control over your trajectory, you can much easily follow the ideal path for your craft than if you didn't had wings 2nd) you can use weaker engines, as long as those can build up and maintain enough momentum to generate lift > weight.

Now, the 2nd advantage is often misunderstood in the sense that is considered something that wings can always exploit.  But that only happens when winged crafts can use very efficient engines (jets for Kerbin and Laythe, maybe nervs in some circumstances {I really don't know}) and at the same time those engines are not powerful enough to be used by crafts without wings.

Considering all that, using a spaceplane to liftoff from Eve is pretty much out of question. Your craft will be too heavy and draggy; you don't have super-efficient engines to exploit; and the horizontal trajectory that make wings useful will hurt the engine performance (efficiency drops with pressure). Let alone other problems of lifting off Eva (drag/gravity losses and overheating).

You can still use wings for your advantage,  to land in a high enough spot so you will be above the worst part of Eve atmosphere when lifting off. Maybe to pick better landing sites while 'biome hopping' and maybe ( in a stretch) even for a very short first part of your ascent to orbit. But traditional, non-winged, staged rockets will be, by far,  the best tool to put your crew back in orbit. 

Given the WallOfText let me provide the TL/DR version:

In most circumstances winged craft are objectively worse, but there's some where they offer significant advantages and can have the upper hand. Those situations are, in no particular order:

-pickings a precise trajectory (in particular a precise landing site) on planets with atmosphere. 

-travelling at around,  including to  space/orbit when jet engines are available.  (Kerbin and Laythe)

-possible edge cases (nervs at Duna? Ion or nuclear engines at extremely high altitudes?) . Arguably,  not practical to explore.

*if necessary I may clarify it, just ask.

**by all means don't just accept it. Check it and see if you reach the same conclusion. 

Edited September 15, 2017 by Spricigo
To fix a mistake

[NicholaiRen]

27 minutes ago, Spricigo said:

Right,  carrying anything you don't use is a waste.   (Of course I know that you use the nervs at some point. I suppose you get what I mean)

Can't argue with taste, if that is the decisive factor for you just go with what you heart asks for. But...

That impresion that planes are superior to more traditional spacecraft often appears. I have no qualms to say: not at all. Those are just different tools that are better suited for different tasks. A hammer is not a bad tool because it don't cut, a lander is not a bad tool because it don't glide.

Also that impression most often arise from a misunderstanding of the limitations and, worse yet,  advantages of winged designs. Let me explain:

For any spacecraft, winged or not,  weight is a hindrance (often referred as the ultimate cost). All else being equal a winged design will be heavier and, thus, less capable. To make things worse for the winged craft they also have more trouble with drag so even less capable (everything else being equal). 

In any case, while subestimating the limitations of winged crafts happens, overestimating its advantages are by far more common (and I risk to say, more nocive).

One common misconception is to consider lift as some kind of magical force that push the winged craft up 'for free'. In fact what happens (simplified for the sake of this discussion. Technically incorrect but close enough for the relevant point there*)  is that wings 'redirects' some forward momentum to upward momentum , the problems are: that 1.wings always produce more drag(resistance) than lift (useful force)2.only a fraction of the forward momentum will be directed upward. 

At this point (if you accepted what I said so far**) you may ask what advantages wings really offer. 1st) better control over your trajectory, you can much easily follow the ideal path for your craft than if you didn't had wings 2nd) you can use weaker engines, as long as those can build up and maintain enough momentum to generate lift > weight.

Now, the 2nd advantage is often misunderstood in the sense that is considered something that wings can always exploit.  But that only happens when winged crafts can use very efficient engines (jets for Kerbin and Laythe, maybe nervs in some circumstances {I really don't know}) and at the same time those engines are not powerful enough to be used by crafts without wings.

Considering all that, using a spaceplane to liftoff from Eve is pretty much out of question. Your craft will be too heavy and draggy; you don't have super-efficient engines to exploit; and the horizontal trajectory that make wings useful will hurt the engine performance (efficiency drops with pressure). Let alone other problems of lifting off Eva (drag/gravity losses and overheating).

You can still use wings for your advantage,  to land in a high enough spot so you will be above the worst part of Eve atmosphere when lifting off. Maybe to pick better landing sites while 'biome hopping' and maybe ( in a stretch) even for a very short first part of your ascent to orbit. But traditional, non-winged, staged rockets will be, by far,  the best tool to put your crew back in orbit. 

Given the WallOfText let me provide the TL/DR version:

In most circumstances winged craft are objectively worse, but there's some where they offer significant advantages and can have the upper hand. Those situations are, in no particular order:

-pickings a precise trajectory (in particular a precise landing site) on planets with atmosphere. 

-travelling at around,  including to  space/orbit when jet engines are available.  (Kerbin and Laythe)

-possible edge cases (nervs at Duna? Ion or nuclear engines at extremely high altitudes?) . Arguably,  not practical to explore.

*if necessary I may clarify it, just ask.

**by all means don't just accept it. Check it and see if you reach the same conclusion. 

I'd assume you've heard of spaceX using rocket boosters that can land again upright.

What if, I made a rocket like that. I had detachable wings so that on entry into eve it would slow me down and I could jettison them when they're no longer useful. So that I'd save fuel on the landing. And then, the rocket's ready to take off again as a single multistage rocket again.

The wings would serve the purpose of slowing down the massive rocket and helping to direct where it lands.

Would that be a valid idea? Because mainly what I'm getting out of this is that while space planes are helpful that doesn't always mean they're as good as they seem. But what about the wings? Surely they could serve some kind of purpose in that. If not, then okay.

I've yet to return a mission back from Duna. So I'm still working on interplanetary flight on a small scale.

I'm practicing my orbital maneuvers and landers on minmus and the mun. Eventually I want to go to Jool and go to multiple moons there to get lots of science. But I suspect that by the time I get to that point, I'll have my entire tech tree done.

 

 

[AeroGav]

11 minutes ago, Spricigo said:

For any spacecraft, winged or not,  weight is a hindrance (often referred as the ultimate cost). All else being equal a winged design will be heavier and, thus, less capable. To make things worse for the winged craft they also have more trouble with drag so even less capable (everything else being equal). 

Just to put some numbers on this -   The screenshot shows that at mach 5,  the Big S delta Wing is producing about 5.5kn of drag and 38.98 of lift.   that's just under 8 to 1 exchange rate.   Look at the stats for the short mk2 cargo bay - 13.98kn drag.         The smallest possible segment of fuselage is making nearly 3x as much drag as our wing.  Also, the wing holds 300 units of liquid fuel,  a mk2 liquid fuel fuselage (short) holds 400.   Instead of 1 big S delta wing we could have had the same lift, drag and dry mass with 5 big S strakes and had 500 units of liquid fuel tankage instead of 3, the only cost being part count.  I later remade this craft with incidence angle on the wings,  and halved our overall drag by flying on prograde lock.

Obviously mk2 parts are especially bad.   Your rocket would use 1.25, 2.5 or 3.75m parts instead.

And yes, this plane doesn't use any oxidizer to fly to orbit because with wings you can make do with 0.3-0.5 to 1 so the NERVs don't need any help.

Wings are just dead weight in space.  They reduce the delta v of the craft with their dry mass, as you say.   But then so do engines, if more wings allow less engines that's a trade off.   With the very low TWR of NERVs , that tradeoff works in favour of more wings,  with chemical engines less so, but if you go chemical you have much worse ISP.    Obviously  you can't go comparing staged rockets and say "look at how inefficient that thing is with its wings, you can't match my delta V" ,  a fairer comparison would be an SSTO rocket with SSTO airplane.

A wingless spacecraft will use less fuel once out of the atmosphere no question, and will have higher delta v, no question.    However, for most of the Kerbol system,  the biggest delta V required in one jump is to get to orbit.    And with the exception of Tylo, all the bodies with >0.3g gravity have atmospheres.   Once you're in orbit,  there's going to be a moon you can go mining at only a short distance away in delta V terms.    Most interplanetary transfer burns are also only a fraction of the delta V cost of getting to orbit, and you can often stop halfway and mine something, or dock with someone and be refuelled - which you can't do midway though the flight to orbit.

So rather than turn this into an "I hate spaceplanes" vs " I hate rockets",  consider what's going to be the best SSTO lander.

Most rocket SSTOs have quite slim delta V margins operating from somewhere like Kerbin, whereas a good space plane should make orbit with 2000-3000,  if not significantly more.    On the other hand,  an SSTO rocket that can land and return from Tylo would be able to land on Laythe and Duna as well, so that begs the question why bother with an aircraft.    That's going to be quite some rocket though.      

Or you could bring a staging rocket which is smaller, use it only for the Tylo mission and the SSTO spaceplane for the other places.

Eve's   and   Moho are special.     Moho because the transfer burn is huge.  Takes like twice the delta V to get there as it does getting from the surface of kerbin to orbit,  with most destinations it's the other way round.    How you'd bring an entire mothership there is beyond me.  

Eve is just an awful place to get out of.   The stock game needs some kind of nuclear turbojet that can use the atmosphere for thrust.    Otherwise,  I did have a prototype staged spaceplane which used nervs etc. to get from 20km to orbit,   and some droppable aerospike boosters to  get us up to 20km subsonic.    I think I'll need to finish that thing off so we can get a better of what an Eve lander might look like.   I'll do the plane option and i'm sure there's rocket versions out there too.  Whichever option you go for though, one thing is certain - it's not going to be re-usable.

 

19 minutes ago, NicholaiRen said:

What if, I made a rocket like that. I had detachable wings so that on entry into eve it would slow me down and I could jettison them when they're no longer useful. So that I'd save fuel on the landing. And then, the rocket's ready to take off again as a single multistage rocket again.

The wings would serve the purpose of slowing down the massive rocket and helping to direct where it lands.

I don't see the point in that.      BTW on eve you will not use fuel to descend,  you will use parachutes.     I am trying to build something with wings so i can make my run to orbit from  about 180 m/s at 20km  to   90km  and 3500m/s (orbit) with nervs.    That way we're getting 800 ISP.   But with eve having twice kerbin's gravity,  getting a twr of 0.4 to 1 is going to be tough.  Hence, wings.    

[Spricigo]

@AeroGav how about docking the spaceplane at one side of the mothership and have one or more engines on the mothership itself on such way that results in a balanced configuration. 

Also suggest to fetch the MM patch that makes docking ports to snap at certain angles.  (Will make docking harder but prevent misalignment)

Finally,  its possible (someone need to test it) that a similar plane with chemical rockets can overcome the Isp disadvantage with weight advantage. (Probably only useful if the spaceplane is meant only for Laythe {and kerbin, where it may use drop tanks/engines}. Mentioned for completeness sake) That last way is how I do to deliver planes to Laythe (never meant to leave the planet or Laythe SSTO {orbital station -> surface -> orbital station, refuelling at orbital station})  the mothership  spacetug stay in space for further use (often repurposed as refuelling vessel).

[AeroGav]

Jeebus,  what did I let myself in for ?   Now   I need to add on the Aerospike drop nacelles to get us to 25km min 

5 nervs,  5200dv and 0.35 twr on eve gravity.  gonna be tight..

the service bay has a mk1 lander can inside.  expecting things to get hot..

edit -scratch notes

from 17km nerv engines will start to get better isp than Darts, so may as well stage them on

considerable oxidizer tankage in body,  if i put lf only mk1 tanks on the drop nacelles, the darts can run from the lf in those and the ox from the body tanks.  would need 1800 lf to use all the ox in the body..     4 darts, onion staged?

Edited September 15, 2017 by AeroGav

[NicholaiRen]

2 minutes ago, AeroGav said:

Jeebus,  what did I let myself in for ?   Now   I need to add on the Aerospike drop nacelles to get us to 25km min 

5 nervs,  5200dv and 0.35 twr on eve gravity.  gonna be tight..

the service bay has a mk1 lander can inside.  expecting things to get hot..

If I'm correct, you'll be one of the first to land and fly a plane on and off of eve correct?

[AeroGav]

28 minutes ago, NicholaiRen said:

If I'm correct, you'll be one of the first to land and fly a plane on and off of eve correct?

If that thing makes it to orbit it will be some achievement, but i am not sure if it hasn't been done before.   It is not single stage to orbit, we are throwing away 4 quite nice dart engines, 4 decouplers, nosecones and mk1 fuel tanks.  Oh and the landing gear.    But yes, if the bulk of the vessel gets back to orbit that'll be something.  My prediction is that it will fall just short and Val will have to jump out and use her jetpack to circularise.     The payload is only 2% of the mass of this stage,  the rest is nervs and fuel.   I don't think you can get more delta v with that twr on nervs.

Thinking about it,  ...  5 nervs generate 25 ec/sec,   how about some xenons to use that...    and  as i start nearing orbital velocity and our tanks are getting empty, i could drop some nervs.  Not very enviromentally friendly, but then Eve isn't friendly to us so why should we care.

[NicholaiRen]

The moment you realize all you need to get the first lander that will be part of the mother ship into orbit was a twin boar engine...

 

I've never used the twin boar engine before so I figured I'd quickly test it before building a MULTI STAGE PAYLOAD ROCKET to get this Duna lander into orbit so it could be docked with. I figured it'd get to 20k feet and then I'd just revert.

 

5 minutes later I'm sitting there looking at it floating around in orbit.

Screw this I'm done.

 

 

BTW I used the landers engines to get it to finish the orbit.

Edited September 15, 2017 by NicholaiRen

[DerekL1963]

One common mistake I see even experienced players make...  they start with a vehicle that's too big and keep making it bigger to attempt to overcome the inevitable problems, which actually ends up making things worse.

[AeroGav]

@DerekL1963  I think that's where I am with the Eve flyer.       The problem is that the first stage (Aerospike) manages to gain about 1800m in altitude before running out of fuel.   Added four 4FT800 tanks worth of extra fuel, it can now climb maybe 3km from starting point at the very most, and the weight is upsetting the flying qualities.

In the end,  I enabled infinite fuel cheat just to see how the nuke stage performs.     Around 20km the airplane wants to go supersonic.    Around 25km at 450 m/s i stage off the darts and disable infinite fuel...

I must say it looks pretty cool from this angle.     With the boosters gone it no longer flies like a dead parrot too.   4.2 to 1 lift drag ratio is good, but with 0.35 to 1 TWR,  we've got 276kn thrust and are still loosing 199 of it to drag.    As we get lighter, and orbital freefall effect kicks in, we'll drift higher and drag will decrease, but at the moment things are pretty stagnant.

Main engine cutoff at mach 15.    At least we're getting sub orbital.   Didn't think we were going to get that far, but in the last few minutes acceleration went up exponentially, so much so i think we could have staged off some of those nukes.   We were accelerating so fast we were at risk of overheat.   I cut the power with the ap at 85km but lift continues to raise it till it's 100km.

Only 166 delta V :-(    Val's gonna have to jump and use her jetpack.      Above 90km we're in space , but as soon as I open the service bay the landing can starts overheating - it starts heat soaking from the very hot airframe.    I close it again.   Val's gonna have to be very quick getting out before the lander can explodes....

well, would ya believe it.  Somehow that tiny amount of fuel was enough.

Still some way off success though.  

[bewing]

4 hours ago, Spricigo said:

1.wings always produce more drag(resistance) than lift (useful force)2.only a fraction of the forward momentum will be directed upward. 

This is exactly wrong. They produce more lift than drag. That is why the lift/drag ratio is a postive number, and why wings are useful at all in the first place.

 

[AeroGav]

2 hours ago, AeroGav said:

Still some way off success though.  

Post mortem time.  Initially this started as a 3 engine ship.  But with 3 nukes at the back and only a lander can in a service bay up front, CoM was just too far back.

So it gained the side nukes to pull CoM forward.    And of course more fuel till i was back down to my original TWR, and ended up with perhaps 300 more delta v total, because payload fraction was already so low we were in diminishing returns.   Actually the extra fuel really came from the strakes stuck on the back of the wing trying to bring CoL far enough aft.

So, the final nuke stage could be made a bit smaller which gives the chem stage some hope of not being utterly ridiculous.

On the chem stage though, I hope we cam do better than those aerospikes.   At eve sea level, they were getting like 210 ISP.   Worse than a Flea solid booster.    Maybe the order should be  Vector > Aerospike > Nerv .  Then we can prefix those with a rover stage to pull it up to a mountain top before launch.

Or maybe i should just learn how to make stock propellers and have that pull the thing to 20km.

EDit - nope,  Aerospike is the best there is,  Mammoth and Vector next best at 190 something.    Tried to build a rocket to lift a lander can , got to 19km.....   jeez no wonder no-one ever goes here

Edited September 15, 2017 by AeroGav

[Spricigo]

1 hour ago, bewing said:

5 hours ago, Spricigo said:

1.wings always produce more drag(resistance) than lift (useful force)2.only a fraction of the forward momentum will be directed upward. 

This is exactly wrong. They produce more lift than drag. That is why the lift/drag ratio is a postive number, and why wings are useful at all in the first place

*reads, notices error, figures out how to correct it, says:

Du'h! Brainfart.  Thanks to point out. I will fix that.

[Spricigo]

7 hours ago, AeroGav said:

Just to put some numbers on this...

All your argumentation don't invalidate what you quoted: Everything else being equal a winged craft is heavier and draggier. I meant literary "that craft" compated to "that craft plus wings strapped".

However that don't imply that the drawbacks can't be overcome.  (In fact I mentioned that winged crafts can effectively use engines that would be too weak without the help of wings) 

Nor it imply that "that craft" don't have  different shortcomings that don't affect "that craft plus wings strapped" so badly.

I think the whole "which one is better?" Discussion is not necessary because we agree that "depends, sometimes wings are usefull, sometimes is better to not have it" ( not counting preferences and the cool/challenging factors)

7 hours ago, AeroGav said:

 a fairer comparison would be an SSTO rocket with SSTO airplane.

Well, not fair to multi staged rockets and planes. IMHO we either compare all option available or the analyses will be incomplete. OTOH , any set of parameters we can choose may favor a particular approach and,  as result, became skewed. 

[Cpt Kerbalkrunch]

@AeroGav, the first thing I think when I see your spaceplane is how cool it looks (and it really does). As a fan of the Purple Widow Maker however, I see those Nervs and cringe (and not just cuz I hate 'em). To me, it's the Holy Trinity of Eve; Mammoth, Vector, Dart. Preferably the Mammoth or Vector (though I've used the Mainsail to good effect, as well). Something big and powerful, in other words. I won't say it can't be done, but getting that thing to orbit would be an exceptional achievement. Especially from sea level; where most engines are slightly better than useless. 

[AeroGav]

1 hour ago, Cpt Kerbalkrunch said:

@AeroGav, the first thing I think when I see your spaceplane is how cool it looks (and it really does). As a fan of the Purple Widow Maker however, I see those Nervs and cringe (and not just cuz I hate 'em). To me, it's the Holy Trinity of Eve; Mammoth, Vector, Dart. Preferably the Mammoth or Vector (though I've used the Mainsail to good effect, as well). Something big and powerful, in other words. I won't say it can't be done, but getting that thing to orbit would be an exceptional achievement. Especially from sea level; where most engines are slightly better than useless. 

The rocket I attempted, used 9 Aerospikes , with an average of 520 units of liquid fuel oxidizer per engine but it was all asparagus staged.     The upper stage was a Terrier with an FT800.

The lower stage got us to 17km at 200-300 m/s before running out of fuel.    The upper stage  not up to the job , having only 0.6 twr.  I was kind of hoping to be well on my way to space at this point , but i guess not.  

Anyway, that fail rocket was 7.4 times heavier than the upper and it only got us to 17km

 

[NicholaiRen]

8 hours ago, AeroGav said:

The rocket I attempted, used 9 Aerospikes , with an average of 520 units of liquid fuel oxidizer per engine but it was all asparagus staged.     The upper stage was a Terrier with an FT800.

The lower stage got us to 17km at 200-300 m/s before running out of fuel.    The upper stage  not up to the job , having only 0.6 twr.  I was kind of hoping to be well on my way to space at this point , but i guess not.  

Anyway, that fail rocket was 7.4 times heavier than the upper and it only got us to 17km

 

It appears we've started our own ultimate challenge.

Design the most effective way to get on and off of eve.

[Helmetman]

Isn't Eve's highest peak the best place to get a surface sample and the easiest place to get back from? (8500meter I think) This probably only works if you allow yourself the rule to quiksave and quikload. One could use detachable fins to glide their if not approached completely accurately if one refrains from quiksave/loading.

I've seen a YouTube video a while ago about a grand tour where one used a rocket in the area of 15 tonnes or thereabout. Personally I would like to be told why it's better going to Eve last since someone made that argument? Is that, last last? What's the best order?
Would you not want to get rid of the Eve landing stage first? I think you can save on aerocapture with the reverse oberth effect at Eve and knowing the exact temperature limits of your craft. Then leave the mothership in the highest elliptical orbit set for kerbin for further slingshotting. Then use the Eve lander for further aerobraking and leave a rcs/ion salvage module in circular orbit of Eve detached from the lander. Land at the peak, get back up and rendesvouz with the salvage module. Enter it and get back to the mother ship who stands ready for going back to Kerbin. Maybe actually save something by limiting the fuel on the module and doing the rest on backpack.

This way you toss most of your motherships heaviest modules away for 1500m/s of delta V from LKO if you do it right.

Going to Jool first may be better because you optimized your design for it. But going to Eve first can be just or even more efficient. 

PS: No I haven't done my own tour yet, probably will between now and R.I.P.

[IncongruousGoat]

All right, speaking as someone who's actually flown such a mission (and, yes, it's completely possible):

All these people conjecturing are planning their missions around some assumptions that are, if you plan well, completely wrong. These assumptions are:

1. Landers are heavy. No, they really aren't. You can get a lander capable of handling Moho, Gilly, Mun, Minmus, Ike, Dres, Bop, Pol, and Eeloo below 1 ton, and reusable to boot, if you build it using ion engines and a command chair. The landers for Vall and Duna need to be liquid-fueled due to delta-V and TWR limits, but they shouldn't weigh more than a ton either. Tylo and Laythe landers can be built in under 3 tons, and the Eve lander should weight at most 20. None of these (except Eve) is particularly heavy, With that in mind, let's look at some more bad assumptions:

2. You can't build a transfer stage big enough to schlep all these heavy landers everywhere. As we've already seen, landers aren't heavy. It is possible to build a transfer stage big enough to move light landers around, but a better idea is to build a modular craft, i.e. one that can reconfigure itself depending on how much fuel is needed for a particular leg of the journey. Better yet, make your craft multiple craft, and only send each lander exactly as far as it strictly needs to go in order to fulfill its purpose.

3. You need ISRU to refuel your big landers and big, inadequate transfer stage. You don't need ISRU, because landers aren't big and the transfer stages needed to move them are adequate.

4. You need SSTOs, orbital assembly, and other complications to move your heavy ISRU rig and inadequate heavy transfer stage and heavy landers to LKO, because efficiency. Since you don't need ISRU, heavy landers or super-heavy transfer stages to move those landers, you don't need SSTOs (or orbital assembly, for that matter) either.

The trick is learning to build things that are only as heavy as they absolutely need to be. Figure out this, and the system is your oyster (or mollusk of choice).

Oh, and if you're curious here's the album of my attempt: https://imgur.com/a/SFUuC

[Spricigo]

2 hours ago, IncongruousGoat said:

All these people conjecturing are planning their missions around some assumptions that are, if you plan well, completely wrong. These assumptions are:

While I agree with what you said, I think maybe you missed one assumption:

Single stage designs are superior. Much of the discussion there revolves around the idea of using a single ship and not  losing parts the whole trip. A mothership with dedicated landers for different celestial bodies is something didn't occurred for many or was dismissed as a lesser achievement. 

Well, doing something for a challenge or for the rule of cool is a good reason as any other.  But IMHO people underestimate the value of a mission with specialized crafts.

[bewing]

Plus, the OP basically specified that this was supposed to be a single ship -- not a flotilla of discardable pieces.