Medusa Grand Tour Architecture. Go where you please!

[Rune]

Looking to traverse the solar system? Just finished the nth station assembly and are looking for new and challenging construction projects? Or perhaps you are just as awed as I am by humongous, multi-part behemoths assembled and designed purely for deep space. The Grand Tour is a challenge very few kerbals ever seriously consider, much less attempt, but in this great enterprise, the real value is the struggle itself: Your can't equal the pride you feel when you turn on a Medusa-class main drives on for the first time! (Don't worry, you will have plenty of time to look at the ship during burns. PLENTY).

Just you look at that big guy! Now some juicy details on how that works. You will notice that I provide 4 craft files at the end, but the ship itself is just the first one. The thing is, as it comes, it's just a completely useless heatshield (completely crucial in the aesthetics department, of course) and the long spine that houses the habitat, comm gear, and a lab to process the scientific data (equally useless of course, since you need pretty much the whole tech tree to build this). No engines, no fuel, but everything docks here. Oh, and a tiny probe you can drop during Jool aerocapture to explore the atmosphere of that unlandable planet. 6 chutes on the probe means I'll actually try to land it.

Then the second file is the tanker that lifts big reds to build the fuel section. This is where it gets interesting. See, the whole idea is to have a reconfigurable ship that you can tailor for a specific mission, and alter as you go. I have no idea the delta-v I'm going to end up using to do a grand Tour, but I'm pretty sure I won't be able to pack it in a single stage, so I've accepted that the mission will have to be flexible and preposition some extra supplies along the way (the most important, the yet-to-be-designed Eve Lander). So, the number of fuel tanks and drive nacelles you install is entirely up to you, and will change you range and possibilities to make this one of the most flexible designs I have ever made. In fact, I'm in the process of repurposing it to transport base modules across the system, more on that soon I hope. This is how it looks once you bring the first tank to orbit and unpack the structural section and the heatshield:

I must admit doing the exact same flight 9 times can be boring, of course, but for most destinations you don't need that many tanks, and you could always pick some other launcher and launch the tanks two at a time or more. I recommend Temstar's wonderful Nova (the one I use for everything here is a fairly basic orange tank+skipper x6booster asparagus capable of putting 50mT on orbit). Here are some delta-v's I came up with for different example configurations of engines and tanks, with the payload being the 2 SSTOs and the Tylo Lander (about 60mT total):

Delta-V's without dropping tanks:

Minimal configuration (1xTanks - 4xDrive pods, 141.04mT): 2019m/s

High T/W configuration (3xTanks - 8xDrive pods, 231.64mT): 4200m/s

Medium configuration (5xTanks - 8xDrive pods, 308.64mT): 5734m/s

Design configuration (9xTanks - 8xDrive pods, 454.64mT): 7876m/s (Note: MR=~e, 530parts)

Max. configuration (17xTanks - 12xDrive pods, 761.4mT): 9836m/s

And of course, auxiliary vehicles! I'm especially proud of the chemical Tylo-Class lander, it is an absolute beast in a very compact package. It sports a full science suite and weights only 50mT, and yet it packs more than 4km/s in each of the two stages and T/W 1.2 under kerbin gravity. Yeah, huge overkill, but I want the dreaded Tylo landing to be as easy as possible. And since I put landing gear on the upper stage, well, it can double as a short of universal lander. It carries itself to orbit with a bit of fuel rom the upper stage, and careful! it carries no RCS tanks, so you have a very limited RCS supply. The two SSTOs are mostly to look good, if chutes were added to the lander you could make do without them, but I wanted to do the atmospheric planets special, and besides, they are really light in both parts and weight (7.25mT and 41 parts). And they can ferry the crew to and from the ship, of course.

The Eve lander is notoriously missing, mostly because I haven't done anything more than a very preliminary design, and because it'll join the expedition in orbit around the target. I'll post it here when it's finished! In the meantime, I'm sure you can think of something you would do with these pieces... Post screenies here if you take her out for a spin!

IMGUR ALBUM:

Javascript is disabled. View full album

DOWNLOADS:

Mothership (Spine and heatshield)

Tanker (Includes the engine nacelles)

SSTO (rated for Laythe and Duna)

Tylo-Class lander (Upper stage doubles as single stage lander everywhere else)

Rune. Reach for the stars!

Edited January 25, 2014 by Rune

[GusTurbo]

Rune, you continue to cement your reputation as one of the best designers around here.

[Rune]

Rune, you continue to cement your reputation as one of the best designers around here.

Thanks! It's mostly a matter of experience, I think, you can learn a lot in the forums! And I guess that the fact it's not just my hobby, but I also study this kind of stuff in the real world also helps. This is in fact a homage to all the Grand Tour mothership concepts in real life that I've seen over the years, with a few other ideas thrown in (like puller nuclear engines, those were inspired half by the Avatar ship and half by the real-life concept MEDUSA for nuclear pulsed propulsion). Notice how the hab section is in the shadow of the nuclear reactors, protected by the fuel tanks, and the exhaust angles slightly under thrust away from the ship. Also, I specifically redesigned the Tylo lander so no nuclear engines are close to it and all RTG's are at the other side of the ship. Couple that with the heatshield, and this manages to look realistic!

A couple of other points I forgot to mention, call them assembly tips:

The tankers are the key to the assembly. Even though the spine and the heatshield have independent RCS subsystems, the tanks don't, so to perform the dockings you must rely on cleverly placed drive pods and their RCS systems. But, with the help of the reaction wheels that I placed in the auxiliary tanks you can see in some the pictures, you can handle the tanks just as they come form the launcher into a docking, even if you have to take things slow when trying a dual side dock. The Dock align indicator mod is awesome to ease the task once you familiarize yourself with it, especially for night dockings, I do those completely by instruments even though the ship is decently illuminated. I totally recommend it, and I mastered docking long before it appeared. It just eases a task that can become repetitive once you master it, fast.

The extra fuel that is there in the grey tanks doesn't only make the tanker look good and ease assembly, it is also useful to refuel the auxiliary crafts, and you have more than enough for an assembly, so you might keep some of them (by this point, I don't have to tell you how to dock them, or where, or point the fact the nuclear engines can also dock behind what they push, not just at the side). They add torque power, and let me tell you, turning this monster takes time. Very stable during burn if you align the nukes properly, though. They do, however, have much, MUCH excess RCS fuel, so they will make you take a hit on delta-V if you keep them, I'm not sure it is worth it. But perhaps for the shorter range versions you could keep them on instead of the rear tanks and use the RCS like it's free.

Rune. I pride myself in the fact that this is a 100% robotic assembly, the ship is patiently waiting on orbit for its crew and launch window.

Edited January 25, 2014 by Rune

[RC1062]

Nice! I think I'll finally get on with my long term mission now after seeing this!

[Umlüx]

thats a great ship! gives me some ideas for my own interplanetary project.

[Deathsoul097]

If you used Ubio-Zur's plugin you could easily cut the number of parts in half, if not more.

I am working on a very similar thing, and I have a giant heatshield that was over 100 parts, condensed down into one with said plugin.

[Rune]

If you used Ubio-Zur's plugin you could easily cut the number of parts in half, if not more.

I am working on a very similar thing, and I have a giant heatshield that was over 100 parts, condensed down into one with said plugin.

Probably, but I do like doing things 100% stock so people only have to muck around with craft files, and for my rig, 530 parts is not excessive to play with. You are definitely on yellow time, but I can make do with a bit of patience. besides, it being 13 different pieces would mean I could probably only use it to get a real advantage in the heatshield.

And thanks everyone for the kind comments! This thing sunk so fast into the second page that I thought you guys didn't like it... and it took a lot to get it done, so yeah, better this way.

In fact, watching the downloads, I see the most popular piece by far is the SSTO, which I threw together the fastest of them all. So what is it bout it that throws you guys off slightly? Too complicated a build? Too many parts? Just so I can focus on releasing the crafts that the customer prefers!

Rune. And the poor Tylo lander sits at 0 downloads... I think it looks cool!

[Umlüx]

i may be mistaken, but iirc people can use welded .crafts without the actual installed plugin as it only combines stock parts.

or was it the save file? hmm.. gotta test this tonight.

[Dodgey]

Can you guys look around for my jaw? I dropped it around here somewhere

[Rune]

Can you guys look around for my jaw? I dropped it around here somewhere

Thanks! Nothing you can't do yourself if you keep playing this game as long as I have...

i may be mistaken, but iirc people can use welded .crafts without the actual installed plugin as it only combines stock parts.

or was it the save file? hmm.. gotta test this tonight.

If I understand how the mod works, it creates custom parts that I would have to include with the download, so in effect I would be providing my own special mod without which the ship would not work. Not that it is a bad mod, mind you, just that I don't use it. Yet.

Rune. But I do have to revisit the carrier concept now that kerbals can walk on floating ships...

[Captain Sierra]

I'm basing my own grand tour architecture off of this (to an extent). I'm opting for more thrust, less fuel, and a welded heat shield. Because I'm not dealing with 80+ useless parts when I can knock it down to 1.

[Camaron]

This craft is amazing but what's the point of the heatshield? Wouldn't something like that only serve as a massive deadweight? The only thing I can figure a starship like this needing one for is Aerobraking + Deadly Re-entry, is that it?

[Rune]

I'm basing my own grand tour architecture off of this (to an extent). I'm opting for more thrust, less fuel, and a welded heat shield. Because I'm not dealing with 80+ useless parts when I can knock it down to 1.

I've always thought that imitation is the greatest form of flattery, so please go on! Post pics here so I can also find out if you have some cool idea I didn't come up with. And perhaps a link so people can see where you got your inspiration from if you post it? I'll be the first to admit my mothership projects (this is like the fifth iteration, each more refined) started more or less when I saw the huge "Vanguard" by Erendrake (google it right now if you haven't seen it!). Though I have of course pilfered from many people along the way...

This craft is amazing but what's the point of the heatshield? Wouldn't something like that only serve as a massive deadweight? The only thing I can figure a starship like this needing one for is Aerobraking + Deadly Re-entry, is that it?

Absolutely none other than looking cool, since I have never installed deadly reentry (and I doubt plates can make do for heatshields for the kind of aerobrakes that it is going to see). I am thinking of welding it if I end up using this ship much due to suggestions, but you are also welcome to just take it out in the VAB and carry on like it was never there, or deorbiting it once you launch, it's an independent craft.

Rune. It took many performance sacrifices to look realistic, so it's kind of the point.

Edited January 29, 2014 by Rune

[Captain Sierra]

This craft is amazing but what's the point of the heatshield? Wouldn't something like that only serve as a massive deadweight? The only thing I can figure a starship like this needing one for is Aerobraking + Deadly Re-entry, is that it?

Good roleplay. Even without DRE, we can still pretend we have to contend with re-entry heating.

-snip-

Look at my sig, link there.

My heat shield is welded, and I'm also using a different fuel tank and engine layout than you. I'm still experimenting with different configurations for the utility section, so nothing past the kethane refinery should be taken as final.

[Patupi]

So you're doing a Grand Tour with no kethane refueling? Cool, I've been designing a ship for the past couple of weeks for that. My current rough estimate is a total of maybe 20,000 dv total, less with small craft doing some of the shuttling. IE send the mothership to Jool orbit, then shuttle landers from there to moons with a small nuke tug. Have you estimated Delta V for your ship yet? I mean with staging drop tanks included in the maximal design you listed. I'd be interested to see what you've come up with. Do you have a schedule for where you're going and in what order yet? I haven't planned mine out other than going to Eve first so I can loose that mass! The Eve lander weighs a hundred tons on it's own!

Right now my ship has 9000 dv without allowing for drop tanks being ditched and loosing the Eve lander early on. Me, I'm trying to be purist and attempting to carry everything with me and no refueling from Kerbin. Gonna be tricky certainly!

(EDIT: I like the idea of the multi-purpose SSTOs, with the rapier engine able to get off Laythe on jet mode, and Duna on rocket mode. What is it's Delta-v on rocket mode only? I'd have thought it'd waste a fair bit on take off on Duna, but then I'm notoriously bad at planes in KSP )

Edited February 9, 2014 by Patupi

[Rune]

So you're doing a Grand Tour with no kethane refueling? Cool, I've been designing a ship for the past couple of weeks for that. My current rough estimate is a total of maybe 20,000 dv total, less with small craft doing some of the shuttling. IE send the mothership to Jool orbit, then shuttle landers from there to moons with a small nuke tug. Have you estimated Delta V for your ship yet? I mean with staging drop tanks included in the maximal design you listed. I'd be interested to see what you've come up with. Do you have a schedule for where you're going and in what order yet? I haven't planned mine out other than going to Eve first so I can loose that mass! The Eve lander weighs a hundred tons on it's own!

Right now my ship has 9000 dv without allowing for drop tanks being ditched and loosing the Eve lander early on. Me, I'm trying to be purist and attempting to carry everything with me and no refueling from Kerbin. Gonna be tricky certainly!

(EDIT: I like the idea of the multi-purpose SSTOs, with the rapier engine able to get off Laythe on jet mode, and Duna on rocket mode. What is it's Delta-v on rocket mode only? I'd have thought it'd waste a fair bit on take off on Duna, but then I'm notoriously bad at planes in KSP )

Hey! Glad to see a fellow masochist. Well, I for sure have it less planned than you do! I have no idea the delta-v I'm going to end up using, so basically I'm packing them most I see reasonable. But I think I do have a couple of tips to pass on on the general trip direction. First, Jool is much better to do first. Why Jool and not Eve? Well, several things. First, it has an atmosphere to break with. That means shaving a big chunk of delta-v, when your ship is heaviest. Yeah, that could also apply to Eve, but the breaking burn at Eve is much smaller. Second, you need one of the big landers for Tylo. Yeah, the Eve lander is going to be bigger. But you pretty much have to choose one of those, because if you want to carry both at the same time you are going to be running into memory issues due to the part count alone. Even if doable in theory, you have to choose in reality. And since you eliminate one of the landers, well... how about only taking the light one with you?

Also, Jool sits at a vantage point on the system, and has a freakingly huge gravity well. Means from there I can pretty much go anywhere, and the hop to Eeelo is so tiny, I would make it on a lander if it wans¡t one of the long ones., But, once you have stopped fooling around the outer system for some small change in delta-v after the initial big kick in the butt out of kerbin, getting back to the inner system is really, really easy: that's when Eve is awesome to break with. Or even better, Duna, to not miss the middle part of the system. Eeelo-Duna with aerobrake is basically nothing in delta-v (and a lot of precision in maneuvers), and puts me in a very good position to go first to Dres, then back in to Eve for the third aerobrake. I think I could squeeze that just by staging tanks around, after dropping the heavy Tylo lander. Then comes the second delta-v hogger: Moho. You just can't cheat there, you have to pay the energy to slow down that much. So better to do it after picking up supplies at either Eve's or Duna's orbit, as close as I can make it on the original fuel. Considering that the SSTO's stop being useful at Duna and get ditched there, so Duna-Eve is done by a very light ship, I might make it.

That puts the two biggest burns (LKO-Jool and Eve-Moho) on opposite sides of the trip, one with the full ship right at the start (pretty much unavoidable) and the second with an empty ship with a tiny lander (the Tylo lander upper stage). Getting back from Moho to kerbin is also hard, but at least you only have to pay half the ticket price again, since you can aerobrake for a... fourth time? fifth if you brake at Laythe inside Jool's system? Anyhow, the idea is to maximize the number of times you get free delta-v. Short of doing several flybys for gravity assists (I might try when going Eeloo-Duna, if the planets are halfway close to a decent position, if only to drop some velocity from the most demanding aerobrake of the trip), I think that is as good as you can get.

As for the SSTO's, it's one of the iffiest things in the whole thing. They just pull 1,700m/s when doing 100% rocket, and that's barely enough to make orbit, I think. Which means you have to land unpowered. On Duna. Yikes. I think before departure, I might want to look more closely at that... perhaps a doubling of wing area is on order. Or just modifying a White Dart, which is much more suited to Duna operation. Or now that I think about it... just ditching them at Laythe, really, the Tylo lander ascent stage can do powered descents and ascents on Duna (the little bugger has 4 point something km/s), and that would be lighter in fact, and have a cascading effect by saving mass at a lot of other earlier burns. Yeah, I think that is what I should do.

Rune. And now the reason for the useless heatshield becomes evident: that things is pretending to be half my fuel supply, not putting anything would feel cheaty. Besides looking cool, of course.

Edited February 9, 2014 by Rune

[Patupi]

Wow, a lot to think about. Right now my Tylo lander is, like yours, a standard High Gravity Lander for Laythe (no planes in my ship More due to my poor history with them), Duna, Eeloo etc... but it gets one of the main mothership boosters docked on the underside for the descent. The High Gravity Lander on it's own has a Kerbin TWR of 2, 4267 delta V, and it's engines can just see around the nuke engines of the mothership booster when attached, so the combined ship has a TWR of 1.58. Should get it down OK. Have to use TAC fuel balancer as since it's assembled in orbit normal fuel lines aren't an option to make sure the booster is used up first.

HGL:

HGL with Booster attached:

I have three of those boosters on the mothership as part of the fuel stack, the stack able to be dumped one tank at a time (it's arranged with seven in each layer, so one dumped from the center, then pairs around the outside 'hexagon'). Each tank has it's own ASAS to minimize wobble during turning this beast. It's still slow. But I'm using one of those boosters to slow the Tylo ship down, one to slow the Eve lander during descent, and the other will be used as a tug during various missions. I'll have to gradually rearrange the stack as I go and the boosters, as they have a probe core and RCS, can be used to do that job too.

Here's a snap of the final ship assembled in high orbit around Kerbin.

As you can see, the Eve lander... that ungainly mess on the front... is a lot to deal with. Much more so than the HGL tucked in behind it that I'll use for Tylo. I'll take a look at the savings of coming from Jool to other bodies, but honestly, I'm going to save so much dumping the Eve lander first I think I'll stick with that.

(EDIT: Oh, and as to aerobraking... well, I'm not sure it's going to do well in that. I don't think I'll be aerobraking at Eve, instead doing an insertion burn. Leaving Jool till later means less drop tanks in the main stack and less wobble, thus less chance for spontaneous unplanned dissembly during such an aerobrake. )

Edited February 10, 2014 by Patupi

[John Crichton]

Very very nice!! I just launched the core of my grand tour ship and the drive/tanks will follow over the coming days. Using a few less tanks because I'm bringing along a Kethane lander allowing me to refuel at a lot of destinations. Still 10.5 deltaV

Weird launch, Jeb grinned the entire trip while the other 2 looked at him in horror. They all survived though...for now.

There are 4 large docking ports in the back for my drives, the one in the front is to refuel before launch and will then push my Kethane lander. There are 4 additional docking ports on the side for 2 SSTO planes an escape pod and a bunch of satellites.

Edited February 10, 2014 by John Crichton

[Patupi]

I planned a Kethane Grand tour... almost a year ago. Yeah, been putting it off for a LONG time. Seeing Czokltemuss' grand tour AAR ages ago got me back into it again... but again I put it off. Finally actually built and assembled the thing! Eventually I think what spurred me was seeing that it was possible without refueling. (I forget who it was I saw, a little over a couple of weeks ago anyway.) When I tried it again I finally found that having such a huge ship (as is needed for stock grand tour) the Eve lander wasn't such a huge proportion of the mass.

Is your ship using Ion engines JC? I mean, you have a lot of solar panels, and unless you're doing a science grand tour there isn't a lot of use for solar like that unless it's Ion drives. Or is this just for fast Kethane conversion? I can't imagine it'd need that much energy! When I'm K-converting I usually make do with four Gigantors at most. Usually a lot less than that. Though of course you'd be including Eeloo and the power would be way lower out that far.... didn't think of that.

When I started my current scheme I did consider an Ion approach, but I wanted it to be mostly stock, and to get any heft would require so many ion engines and tanks... the part count would be seriously hefty!

(EDIT: Love the teeth grating look Bob is giving in that shot Anyway, looks like in the bottom right they are happy after they got to orbit. Or is that just relief?)

Edited February 10, 2014 by Patupi

[John Crichton]

The only reason I have that many solar arrays is because I'll have to retract some when docking the 2 larger SSTOs...and yup, further our I'll be happy for those extra arrays. Haven't decided on a final loadout yet, so the core is quite modular.

As for them being happy once reaching orbit, yup...Bob even made a weird dance out of joy. I guess they didn't believe I could lift those 123t into orbit without crashing

I so wanted an ion drive grand tour ship, but it's simply not feasible in stock...and while I'm willing to use that Kethane mod (and that funny spinning habitat), I don't really want to use any other mods. Would need mods to make ion drives work on such a large ship (especially if I want landers with me).

Edited February 11, 2014 by John Crichton

[Patupi]

I've seen quite a few mods for ion drives, but most seem to make them at least a little over-powered compared to stock. I think one of the stock-a-likes has some boost to ion tech, mostly in larger Xenon tanks, and some multi-engine ion-drive. Still wouldn't be enough I think for ships THIS big with ion propulsion.

(Oh, and I should add that, although Mechjeb is the only non-stock part I use, I do use quite a few mods in this one. Editor extensions, AGM, Texture Replacer (and pimp my kerbals pack), enhanced navball, TAC fuel balancer (necessary with all those drop tanks with no fuel lines... since they are docked & assembled in orbit), select root, alarm clock, crew manifest, and Clouds & City lights. Actually I'm thinking of taking out texture replacer and clouds and city lights as I've had a few crashes... though that might be the aggressive compression in active texture compressor I was using. It certainly wasn't parts textures crashing stuff! )

Edited February 11, 2014 by Patupi

[Odielthen]

I had intended to start my own grand tour with a design that reminds me of the one you posted. I only have the first stage in orbit right now, so changing things won't be too much of a problem. I have learned that I probably don't have enough fuel though! Currently I have plans for six big red tanks of fuel running eight nukes. I have some skipper engines that will be attached at some point in case I need a lot of thrust right away. I've never made it past Duna, but I have learned that nukes are very slow! Much like your design, I have intended my ship to be completely robotic in assembly. The concern I have is if I will be getting enough solar energy at the outermost planets. I don't see any way to shut down the robotic controls, so they will be a constant drain on energy.

[Patupi]

Did you mean robotic because I'm using Mechjeb? It does have a crew, six as a matter of fact. Right now I'm considering a different design of Eve lander and meanwhile the whole assembly is waiting at a 650km orbit. I have a slightly better design, but although it does only weigh about 85 tons rather that a little over a hundred, it looks similar to more generic Eve landers. Central core and tall 1.25m tanks with aerospikes on around the core. OK, my 'core' is just a 2.5m ASAS unit and gets dumped with the last radial tank. Then it goes on the last two stages. Still kind of looks boring to me.

Basically still thinking.

[Rune]

Did you mean robotic because I'm using Mechjeb? It does have a crew, six as a matter of fact. Right now I'm considering a different design of Eve lander and meanwhile the whole assembly is waiting at a 650km orbit. I have a slightly better design, but although it does only weigh about 85 tons rather that a little over a hundred, it looks similar to more generic Eve landers. Central core and tall 1.25m tanks with aerospikes on around the core. OK, my 'core' is just a 2.5m ASAS unit and gets dumped with the last radial tank. Then it goes on the last two stages. Still kind of looks boring to me.

Basically still thinking.

I think he meant robotic as in "no kerbal risks life an limb to assemble something which may or may not work". And yeah, I struggle to keep my dudes out of harm's way until I have a design certified as safe. So far, no deaths in career!

So yeah, good luck on your respective Grand Tours, and I hope you both get nice ideas from here! Feel free to pilfer anything you think is cool, or ask whatever you wanna know.

Rune. Though more than a few flights reverted to launch.

[Captain Sierra]

I've seen quite a few mods for ion drives, but most seem to make them at least a little over-powered compared to stock. I think one of the stock-a-likes has some boost to ion tech, mostly in larger Xenon tanks, and some multi-engine ion-drive. Still wouldn't be enough I think for ships THIS big with ion propulsion.

(Oh, and I should add that, although Mechjeb is the only non-stock part I use, I do use quite a few mods in this one. Editor extensions, AGM, Texture Replacer (and pimp my kerbals pack), enhanced navball, TAC fuel balancer (necessary with all those drop tanks with no fuel lines... since they are docked & assembled in orbit), select root, alarm clock, crew manifest, and Clouds & City lights. Actually I'm thinking of taking out texture replacer and clouds and city lights as I've had a few crashes... though that might be the aggressive compression in active texture compressor I was using. It certainly wasn't parts textures crashing stuff! )

I now feel compelled to go run a manned Joolian tour with NFP engines.

Where's that 10MW Reactor when I need it! I gotta cluster 5MPDTs so I can haul my 30 ton craft out there.