What do you place on a Mothership/Interplanetaryship?

[Valley]

I am designing a true space ship for travelling the planets, once 1.0 comes out. I know it has to have a ton of docking ports and use nuclear engines. But what else should it carry? And what should I leave out as worthless or something that attending ships will handle? It is sandbox but I am taking a science lab, because I still like science, even in role play. But what is the "Needed" list of equipment and what is "That's nice to have" list?

Remember, the mother ship will likely only visit a planet after the target planet has been slightly developed (at least a refueling station in orbit or fueling ships already waiting for it). And what would you think of as the Max. crew number?

[Windspren]

I would take a spaceplane that can operate in both oxygenated and non-oxygenated atmospheres. Also, bring 2-4 landers so that you have a backup. I would have space for 15 kerbals so that you could start a colony. Bring some probes with ion engines and science equipment, and once 1.0 comes out, resource scanners so that you can map the planets/moons.

[samstarman5]

I still have in my plans in assembling my own all-stock interplanetary ship, with habitat modules, science module, and drones to send down to planetary bodies(which includes asteroids, moons, and dwarf planets) that the ship comes within range of. It will be assembled in orbit with just a pilot and engineer in regular control of the ship along with a probe core. Three scientists will be kept in a habitat module under hypersleep. Nothing will go wrong, and the mission will be a fantastic success.

Just remembered to bring along a backup communications module. Gotta write that down...

[Scotius]

My own motherships are usually just monstrous tugs. Their main duty is to carry landers and space station modules to another planet, drop their cargo in designated orbit, then return home for another payload. Or stay in orbit serving as a temporary fuel depot until mission is over - then bring the crew back to Kerbin. For such kind of operations simple is better. Docking ports of at least two sizes for refuelling, plenty of RCS propellant, small lake of fuel, energy sources form the core of the ship. Rest is just fluff - KAS winch or two, lights, big antenna for communication, some science equipment in case i get a chance to complete a contract along the way.

[EzinX]

Does anyone actually know how to reliably even do this? I've tried to bolt landers to interplanetary motherships several times in several different campaigns. Every time, I would get unacceptable (and unrealistic) wobble that was mission-ending. I usually ended the campaign playthrough at that point. I've heard you can "fix" this with cheat struts, but what I would really like are structural docking ports that bond the 2 spacecraft together in a strong, stiff manner like real spacecraft designers would do it.

[DunaRocketeer]

The way I've solved that is to actually make my mothership the lander: Leave the majority of your propellant tanks, Science lab and whatever else in orbit, and take the drive unit (2-4 LV-N's) with a lander-can, all your science instruments, a small rover etc, down to the surface.

[Scotius]

Weird. Sr. Docking Ports are usually rock-solid when i'm hauling my heavy, overbuilt landers around. If you have troubles, try emptying lander's tanks into the mothership to lessen the strain on the ports.

[Taki117]

I play with KSPI so I usually build my ships a little different. My "Mother Ships" always include a command section, with a decoupler/docking port and some extra fuel and engine so that it can be jettisoned in the event of catastrophic failure on mission. IT also usually includes an aerobraking heat shield for use either at the destination, or upon return to Kerbin (I play with DRE). A habitat section, featuring enough living space for twice the number of crew on mission, this section typically includes a lab/habitat module and a gravity ring. The third section I build is the Power Generation Section. This section features a nuclear reactor, electrical generator, and associated hardware. I also usually include some type of radiation shielding between this section and the living section, though this is usually just me putting a heatshield and decoupler between the two, so that the reactor and drive sections can be jettisoned should the need arise. The final section is the Drive section. This is where the fuel and engines are mounted. Typically this is a thermal rocket attached directly to the reactor, and using the fuel as the previously mentioned radiation shield, or, much more commonly, it is nuclear engines. In the absence of the reactor section, due to either technological or engine limitations, one set of ventral and one set of dorsal solar panels is added to the drive and habitat module. An emergency set is always included on the command section.

[prophet_01]

I prefer to start the design of such a ship with a heavily struted core construction. That center piece only contains a minimum of fuel, the engines and a vast number of docking ports to attach the required number of NASA-sized fuel tanks later on. Since everything heavy is directly connected to the super-struted core the whoble is at least manageable. I usually put the engines somewhere radially around the midle of the ship to decreases the whoble further. Depending on the required delta-v for a mission, I drop the fuel tanks along the way. I try to keep the whole design as konpact as I can, as my experience tells me that long or wide designs tend to cause problems

it's still challenging as hell and takes hours if not days to complete

[magnemoe]

Weird. Sr. Docking Ports are usually rock-solid when i'm hauling my heavy, overbuilt landers around. If you have troubles, try emptying lander's tanks into the mothership to lessen the strain on the ports.

Yes, if you have to transport long items its usualy better to pull, disable reaction wheels on long items who are docked, if you have an asempled ship more than 20 meter long with reaction wheels in both end it might start to fight it self.

Multiple ways to do this, if you send a large ship with lots of kerbals and your target is an low gravity world you can just as well make it able to land, this will be useful in 1.0.

This is my Jool mission ship, 5 2.5 meter stacks each of the four corners has 2 LV-N and a drill for Karbonite.

Core is bridge and extraplanetary launchpad workshop. 3 of the sides have two hitchhiker modules, the last has equipment for karbonite and launchpad. 3 3.75 meter drop tanks, to the right I have an 9 engine heavy tug to push it to kerbin SOI.

[Spartwo]

2 omni-landers + a single Tylo attachment for it and a Lathe lander. That's always my tour setup.

[Cirocco]

Depends on what you want the mothership to do. If it's for exploratory purposes (my designs usually are) then here's what I tend to inculde:

- kerbal storage capacity: Motherships usually carry relatively high kerbal crews in my case (20 and up) for roleplay reasons as well as colony/base crew rotation reasons.

- landers crammed full of science equipment: You want as many landers as you feel comfortable with in the mission plan. Either go with several specialised (possibly one-shot) landers or with only one or two broad purpose, re-usable landers. Both have their advantages: specialised one-shots are very often small, light and easily incorporated into the mothership design. Re-usable ones are, well, re-usable. Also, you'll only need one or two for several different mission targets. That being said, they won't be as efficient as dedicated landers and they will likely also be bigger and more difficult to incorporate into the design.

- science lab + science equipment: optional, but if you're going to be using multi-purpose landers, you'll want to be able to recycle the science experiments. It's also nice to have dedicated science equipment on the mothership itself, that way you don't have to always use those of the landers when you're just orbiting, aerobraking, etc.

- satellites: on exploratory missions, leaving satellites in orbit is a nice way to be able to fulfil contract later down the line.

- (sacrificial) surface probes: if landing isn't planned, undesirable (Eve, I'm looking at you) or impossible (Jool, Kerbol), then sacrificial probes are a great way to get science anyways. Pack a couple and send em off with a wave and a tear to get blown up in the name of science.

- Escape pods/science delivery pods: single man pods with limited fuel supply can have a two-fold purpose: either to evacuate Kerbals in case of emergency (for role-play purposes unless you run breakdown mods) or, more practically, as science carriers upon return to Kerbin. Large motherships are often incapable of landing on Kerbin in one piece, and rather than send up another mission to collect science, it can be easier to just cram all science into one pod and send it down.

- Supply and utility module: usually includes but is not limited to electricity generation, SAS, batteries, monopropellant for use on both mothership and landers, possibly some xenon tanks if you want to refuel some ion-powered things during the mission

Other than that, you obviously want some docking ports and lots of lights. That’s about all I can think of.

[Jouni]

Does anyone actually know how to reliably even do this? I've tried to bolt landers to interplanetary motherships several times in several different campaigns. Every time, I would get unacceptable (and unrealistic) wobble that was mission-ending. I usually ended the campaign playthrough at that point. I've heard you can "fix" this with cheat struts, but what I would really like are structural docking ports that bond the 2 spacecraft together in a strong, stiff manner like real spacecraft designers would do it.

Everything starts with a good design. If your ship looks like a ball, it's probably a good design. If it looks like a stick, it can be good or bad. If it's two balls at the opposing ends of a stick, it's probably bad.

I usually start with the engine module. It should be a single rigid module with engines and fuel tanks. Ideally most of the mass of the ship should be in the engine module, but even if that's not true, the center of mass of the ship should always be within the module. Engines should be behind the center of mass, allowing you to use thrust vectoring to control the ship during maneuvers.

Other heavy modules, such as large landers and fuel tanks, should be docked directly in front or behind the engine module. Their centers of mass should always be as close to the docking port as possible. Smaller modules can then be docked to the remaining ports.

It's important to not abuse the controls. Just as you don't burn the engines all the way to Jool, you don't want to actively rotate the ship all the time. When you're turning a large ship, you switch SAS off, start rotating the ship manually, and wait. Towards the end of the turn, you start slowing down manually, and try to stop the rotation as close to the correct heading as possible. Only after that you switch SAS on and let it do the rest.

Edited March 12, 2015 by Jouni

[Thomas988]

I've built one mothership/big interplanetary craft in my entire time in KSP, named Dunar 1. It was supposed to go to Duna, but I built it so big the framerate became impossible to work with. Plus I had no idea about Delta-V or the Trust-to-Weight ratio back then, so I doubt it could even get to Duna in the first place.

What's on it are three probe landers, three rovers, a manned lander, as well as a huge interplanetary transfer stage with four nuclear engines.

Hey, I knew nothing back then! (I'll post a pic of it once I get home. At school right now!)

[EzinX]

Everything starts with a good design. If your ship looks like a ball, it's probably a good design. If it looks like a stick, it can be good or bad. If it's two balls at the opposing ends of a stick, it's probably bad.

It's important to not abuse the controls. Just as you don't burn the engines all the way to Jool, you don't want to actively rotate the ship all the time. When you're turning a large ship, you switch SAS off, start rotating the ship manually, and wait. Towards the end of the turn, you start slowing down manually, and try to stop the rotation as close to the correct heading as possible. Only after that you switch SAS on and let it do the rest.

This is what would kill my ships. I would need to do a long burn of 20-40 IRL minutes. Trouble is, especially with physical timewarp running, little pertubations would get started in one section of the ship. The oscillations would be amplified by the docking port to the other piece. SAS tends to try to correct for this in a way that actually exacerbates the problem, making the ship oscillate even more wildly. Docking ports are treated like springs by the physics solver, so energy that never existed is being injected into the system, making it even worse. Mechjeb's autopilot is also more aggressive, making this problem worse - and in my playthrough, I consider it completely legit to use mechjeb to calculate a correct transfer trajectory and to execute planned burns.

Anyways, I found that if I cut back the thrust and was willing to wait 2 hours or something to do a burn at 1x, sure, I could do an interplanetary burn. It was just not worth it to me to wait that long, I quit my campaign in the hopes that future patches would fix this.

I feel the implementation of physics in this game is wrong. Pieces of ships should be tied together by rigid body transforms, and the game should only compute stress analytically and not attempt to apply it using springs using inaccurate integrations. At the force summing stage of each timestep, the game should compute all of the uncontrollable forces on a ship, check the ship's intent (basically there would be a number of possible flight modes that reflect what the ship is trying to do), and then cancel all unwanted forces using the ship's engines and control surfaces, limited of course by their maximum available torques and thrusts at this timestep. You simulate the fact that rocket engines can't increase in thrust instantly and control surfaces can't deflect instantly by making their maximums reflect the average availability over a delta T.

[Norcalplanner]

Check out the Milne, the craft I used for the Jool-5 Kethane challenge. Just click on the badge in my signature. The drive section detached to become a universal lander, suitable for everywhere except Kerbin and Eve. It could also bring down a science lab, or a supplemental fuel tank. The design included two small satellites for impact testing and four Kethane scanning probes.

[lextacy]

You do this...........

A close look reveals that you can use a lander (Dragon v2) and return capsule (Orion) and they never touch their fuel untill needed. The main ship full-fills the fuel eating duty for transit to and from planet.

[Kar]

Since it seams when 1.0 gets here more things are going to be introduced, I will probably start a new career game. Also, I am expecting new parts with 1.0, so I wonder if the current designs become obsolete.

[Jouni]

I feel the implementation of physics in this game is wrong. Pieces of ships should be tied together by rigid body transforms, and the game should only compute stress analytically and not attempt to apply it using springs using inaccurate integrations.

Have you been in a tall building during an earthquake? Have you seen a ship bend in a storm? Have you been in a plane during heavy turbulence? Real structures wobble and bend, just like KSP rockets should. The right amount of wobbliness is a matter of taste, but the challenge of designing large ships that behave well should always be there.

[problemecium]

Here's what's currently attached to my Jool mothership:

2 portable stations

Tylo lander

Laythe lander

2 small general-purpose landers (for the small moons, one lander being a spare)

2 skycranes with rovers (same deal)

2 ion-powered boats (same deal again xD)

6 miniature ion probes

4 space tugs (standard and mini space tugs, each with a spare)

And of course the crew quarters, science lab, and (to be added) escape pods.

[Vanamonde]

The mothership should (in my opinion) be only fuel, engines, power sources, and crew quarters.

Then you pile the payload modules on.