How Do I SAFELY and EFFECTIVELY launch modules for my space station

[Glaran K'erman]

Payload fairings suck, cargo bay is COMPLETELY useless. Getting very frustated here and I know I am doing very little incorrectly, this game is simply not allowing me to construct EFFICIENT and SAFE craft.

What does this game want me to do to launch big payloads, I've given up trying.

Edited June 17, 2015 by Glaran K'erman

[Red Iron Crown]

Maybe show us a picture or two of how you're building your rockets and we can give some advice on how to improve them to be more safe and effective.

[kStrout]

How large are your space station modules, I never had issues, just stick them in a 2.5m fairing and stick a 2.5m rocket below it, add boosters for larger payloads. Can we see some pictures of your modules and launch vehicles?

Edit: Ninja'd

[Glaran K'erman]

I would love to but I would have to rebuild all the different iterations I went through. I will post the most recent couple though. Launch vehicle stability/delta-v no problem, the issues I have are the limitations on how parts can be connected to the vehicle. For instance a tricoupler with ports attached (also attached to the module I want to launch) will not attach to seemingly intuitive recieving designs with the same tricoupler with either ports, stack separators, or decouplers attached. Modules stored in the cargo bay have only ever stayed in said cargo bay even though I never observed to meshing of parts, RCS moves the whole bay not just the module. So that pretty much has left me with payload fairings which are.....terrible.

[Red Iron Crown]

The tricoupler-to-tricoupler attachment thing is a limitation of the tree structure that KSP craft use. You can workaround it with struts or docking ports, but I've found it better to avoid such designs if possible.

WRT modules in the cargo bay, are they being decoupled via docking port or decoupler before RCS is used? (Sorry if this is an obvious question)

In what way are you finding payload fairings terrible?

[xtoro]

Attaching a 3-point coupler to a 3-point coupler in the VAB doesn't work because it really only attaches one of them. Docking in space together will work however. Also, is sounds like you're saying that your payload moves around in the cargo bay? If so, attach struts from your payload to the inner walls of the cargo bay.

[capi3101]

Okay - so the question is how to launch a large payload. About what mass range are we talking about? Most I've ever gotten into space with a reliable booster was 450 tonnes on a dare - I'll have to search for the screenie. Meantime there's this one, which does 180:

Granted, this was from an earlier version of KSP (so it probably could do more now; stock air recommended TWR on the pad for 1.0.x is 1.5 or thereabouts). My observation, though, has been that anything that worked in pre-1.0 KSP will work in the current game, provided you A) add fins, add nosecones and C) fly it carefully down towards the ground (don't start turning until 5k, then be gradual about it - try to be at 45 degrees by 15k but don't rush it and DEFINITELY don't turn all at once). As for attaching the payload, struts are still going to be necessary, even if you use a fairing. All the fairing does is protect the internal bits from thermal damage and reduce drag; it doesn't add much in terms of structural stability to the vehicle. They're expecially necessary if you've got a really narrow connection point (like say if you've got a docking port on the bottom of the payload and the booster uses large or extra-large radius parts right off.

If you're having problems with parts coming apart from one another, you could try an old trick from the days where the connections weren't as strong - put cubic octagonals on the side and stitch those together with struts. Like this:

Makes things a big stronger - less likely to come flying apart at the seams...

BTW if you think stock fairings blow and aren't adverse to mods, try Procedural Fairings. Waaaay more user friendly, IMHO.

The bit where the parts mesh to one another in the cargo bay - been there, and I agree it sucks. Had it happen to me the other day - I moved the payload around and thought I'd reattached it to the right spot, only to discover that I had dumped the probe core controlling the thing smack into the docking port that was supposedly holding it in place...

Edited June 16, 2015 by capi3101

[georgTF]

Finnicky payloads require or even demand a different lift approach/ascent. Here's a few tips:

- Use a stable lifter with above average fuel. You *will* waste fuel. This is intentional.

- Fly straight up to above 35km using lower than normal thrust. Try to keep velocity between 200-300 m/s. Do no break mach 1. Not even near it. This minimises the effect of drag and reduces the likelyhood of the rocket being pulled by air friction. This costs/wastes fuel.

- Try to avoid SAS lock because it has a nasty habit of wobbleing rockets to death. If you must make manual inputs be very gentle and try to keep pointing straight up.

- Don't worry too much about inclination (veering north/south), but try not to let the rocket turn retrograde.

- As your lifter climbs, the effect of gravity decreases and velocity increases. Adjust throttle as needed to avoid going too fast.

- Once past 35km air friction subsides to the point where it is safe to gently begin turning prograde. Gently. Hit Alt-F5 to quecksave a specific save and use Alt-F9 to reload if bad things happen.

In addition to being susceptible to drag, fiddly payloads often lack structural integrity and can be broken off by high thrusting engines. Sadly high thrusting engines are needed for sub-optimal 35km prograde turns otherwise the rocket will fall back down before it reaches orbital velocity. If high thrust is impossible, then it's best to keep the angle of ascent high and keep wasting fuel. If the payload can be strutted up tightly then it's time to throttle up and gain orbital velocity.

If you keep running out of fuel, use stonger engines and bigger tanks. This ascent is initially slow and steady but eventually needs to make up for it. Maybe someone has a better idea but i prefer Mainsail + Skippers for the job unless payload is also stupidly heavy as well as drunk & disorderly.

If wobble is incurable then the lifter needs to be redesigned. Try a more vertical lifter with additional vertical support structures. Gratuitos struts should be used to connect the payload to the load bearing part of the lifter. If drop tanks are used, struts *can* be used to attach payload to them, but keep in mind that they will be dropped.

By 'more vertical' i mean a central stack with 2 additional companion stacks that can be used as anchor points for struts keeping the payload in check.

Image of a medium sized rover/lander hybrid craft strutted up on top of a medium lifter. This failed to make orbit on the first attempt but second time with an extra bit of fuel and better piloting it worked.

A rather silly ore transporter rover/lander secured using vertical extensions of the lifter. I was too lazy to rebuild the lifter with fuel tanks instead of girders. Both ideas would work.

In conclusion, i too have been driven crazy by KSPs refusal to let me lauch silly things into space. My stubborn solution was to WASTE FUEL, lift straight up above 35km thereby wasting more fuel, make sure that i have firmly strutted up the payload, keep wasting fuel and eventually it relented and let me have my way.

[edit]

Also, if you have rover wheels, engage the parking brake to keep the wheels from spinning. Not sure if they affect anything but they might.

That trick capi3101 mentioned to secure central tanks to one another is an oldie but a glodie. However i will be damned if i will ever resort to it again post 23.5 joint strenghtening. It's a flaw in the game and using this as a solution would increase part count. But it does work. I just hate it.

Edited June 16, 2015 by georgTF

[SAI Peregrinus]

That uses modded parts because stock engine clusters & tanks could work for such a payload, but they'd lag to all hell. And I'm not Whackjob, so I don't like having craft that turn my game into a slideshow.

Anyway, 1000 Tonnes to a 100km circular orbit, reliably. Behemoth Aerospace engines, Procedural parts for the tanks & decoupler. NRAP test weight.

[Mic_n]

you're launching 1000T payloads? Dear god, that's nuts. No wonder you're having trouble launching them. I mean.. play the game the way you want to, by all means.. but IMO if you're trying to launch things you can't achieve with even the biggest stock engines out there, then you're doing it wrong.

Edited June 17, 2015 by Mic_n

[Lelitu]

The best approach I've found in 1.0.2 for superheavy constructions (>100 tons) is quite simple.

Do it the way they did the ISS. ship up standalone components, and dock together in orbit.

This works, and works well, because each component can be kept to a cylindrical form, and reasonableish mass, which plays really nicely with stock aero and lifters.

It's not always the prettiest, but does get quite effective structures a long way.

Is how I put together my jool orbit refinery and science lab base. I don't have the total mass on hand, but the volume is such that it could not have been launched sensibly as a single payload. Too long and wide.

[Glaran K'erman]

Thanks guys, definitely helped me slow down and think it out a bit. I've linked to pics of the two modules and vehicles that got them there, including the original(ish, it's the second version becuase I saved over the original worst model) build that gave me headaches. In the end I opted to ditch a cargo bay or fairing all together in favor of a bit of weight balancing and good old fashioned piloting. One pic is the original "Kalpha" module that I BARELY got into orbit. The payload fairing as some of you have mentioned produced a highly unstable load that wobbled 6-8 deg off axis nearly the entire flight. I really don't know how I got it but yea it worked out and then I ran into the trouble with the second module that includes the Zoology lab. Thanks again and I think I am going to move this over to a different place on the boards to just get some cool ideas on how to build it out some more. I have big plans!!!

Original bad design for second module 1: https://www.dropbox.com/s/2tr4mhdgc1d1fl1/Screen%20Shot%202015-06-16%20at%209.24.45%20PM.png?dl=0

Original bad design for second module 2: https://www.dropbox.com/s/6ch0ipzxgz40q7t/Screen%20Shot%202015-06-16%20at%209.24.58%20PM.png?dl=0

Second module vehicle: https://www.dropbox.com/s/49vbg4wnb2m90ko/Screen%20Shot%202015-06-16%20at%209.01.46%20PM.png?dl=0

Kalpha module vehicle: https://www.dropbox.com/s/b2z1fdz02r53vz9/Screen%20Shot%202015-06-16%20at%209.00.34%20PM.png?dl=0

Station 1: https://www.dropbox.com/s/ybirbu0xppxfknc/Screen%20Shot%202015-06-16%20at%209.02.51%20PM.png?dl=0

Station 2: https://www.dropbox.com/s/zdosir8hz6f79cx/Screen%20Shot%202015-06-16%20at%209.03.26%20PM.png?dl=0

[A_name]

finnicky payloads require or even demand a different lift approach/ascent. Here's a few tips:

In conclusion, i too have been driven crazy by ksps refusal to let me lauch silly things into space. My stubborn solution was to waste fuel, lift straight up above 35km thereby wasting more fuel, make sure that i have firmly strutted up the payload, keep wasting fuel and eventually it relented and let me have my way.

This is hilarious.

Regarding OP:

If you like mods, check Kerbal Joint Reinforcement and Claw's Stock Clamshell Fairings (assuming confetti fairings is why you don't like fairings, why don't you like fairings anyway?).

[Glaran K'erman]

I'll check them out and yes I forgot to mention that. My beef with fairings is that they only play into the aerodynamics, nothing to do with structure! I know it may be a bit to ask for the ability to add reinforcements to the inside of fairings but at least make it bounce around INSIDE the structure and not ghost through all over the place.

[A_name]

I'll check them out and yes I forgot to mention that. My beef with fairings is that they only play into the aerodynamics' date=' nothing to do with structure! I know it may be a bit to ask for the ability to add reinforcements to the inside of fairings but at least make it bounce around INSIDE the structure and not ghost through all over the place.[/quote']

There is a technique to strap stuff to the inside of fairings. It's a bit tedious but works. You Have to build a kind of scaffold around your rocket with structural girders. Use symmetry to attach three or so horizontally extending from the center stack, then connect vertical ones on top of the edge and build upward, until the vertical part reaches your payload. Then attach the struts, with the same number of symmetry as you used for the scaffolds, from the payload to the scaffolds. The struts will in fact attach to the inside of the fairing instead of the scaffold. Then remove the scaffold. Scaffold.

[SAI Peregrinus]

you're launching 1000T payloads? Dear god, that's nuts. No wonder you're having trouble launching them. I mean.. play the game the way you want to, by all means.. but IMO if you're trying to launch things you can't achieve with even the biggest stock engines out there, then you're doing it wrong.

Oh, I've never had a NEED to launch a payload that big. I was just making & testing a bunch of launchers (1T, 5T, 10T, 25T, 50T, 100T, etc) and got carried away. Almost anything over 50T I build in orbit. Though I did see a contract to mine 140T (14,000 units) of ore from Eve and deliver it to Gilly, doing that in one go would require a monstrous launcher.

[MaverickSawyer]

Oh, I've never had a NEED to launch a payload that big. I was just making & testing a bunch of launchers (1T, 5T, 10T, 25T, 50T, 100T, etc) and got carried away. Almost anything over 50T I build in orbit. Though I did see a contract to mine 140T (14,000 units) of ore from Eve and deliver it to Gilly, doing that in one go would require a monstrous launcher.

Ore... from Eve... to Gilly...

*spasm*

One moment...

*drags contract writer out back and beats him*

[KerikBalm]

Ore... from Eve... to Gilly...

*spasm*

One moment...

*drags contract writer out back and beats him*

Note that you don't actually have to do that to complete the contract.

It may tell you to mine X units of Ore on Eve

Then to deliver X units of Ore to Gilly

You can in fact just mine the 600 units on Eve, and forget about those... and then ship 600 units of ore from *somewhere else* to gilly.

You could probably even get the ore direct from Gilly.

I know when it asks me to land X units of Ore from the Mun/Minmus... I can just launch a new craft with the ore tanks already full... hop 5 meters into the air to get it to change status from ready to launch to landed, and the contract will complete.

Likewise, if it wants me to deliver the ore to kerbin orbit, I can just launch a SSTO with some full ore tanks to orbit, after my Mun/Minmus ISRU mined the required ore amount (assuming I want to simply use that ore to supply a Mun/Minmus fuel depot, and not go through the trouble of bringing it to kerbin orbit... although in that case its probably easier to just exist Mun/minmus SOI, complete the contract, and then reenter it and rendevous with the fuel depot).

The same tricks should work with Eve/Gilly.

The only reason for ISRU on Eve is so you can land an empty rocket, and fill it up.

The rocket will stage like crazy of course, and the ISRU equipment should be left behind

[capi3101]

Alright...so your payloads are somewhere in the 80 tonnes range then? No problem - we can calc the asparagus for that easily enough.

First, let me point out Temstar's guide to good asparagus. Those guidelines were written for 0.20 but they're still good in the days of 1.0.x (the main differences being that you don't want your TWR to be quite as high as it needed to be in the old days - 1.5 is plenty - and that you actually need nosecones and fins these days). 0.20 was the days before thrust limiters, so you couldn't fine-tune your engine thrust; these days you can.

So let's do the math based on those guidelines. Your payload is 80 tonnes; 15% payload fraction gives you a theoretical rocket mass of 533 tonnes. With a 1.5 TWR on the pad for that mass, you'll need 7840 kN of thrust on the pad. Putting 22% of that in the core - 1724.8 kN; a Twin Boar set at 92.5% could do the job. Alternatively, you could use a rocket cluster (like Temstar used to do). BZ-52s, Cubic Octagonal Struts or even Modular Girder Segments could easily be added to the bottom of a fuel tank, and the rockets attached to those. Say 4 Swivels and 6 Reliants - that would give you 1879.02 in the core, a little more than you need but nothing that can't adjusted (adjust the Reliants to 87% - you want the Swivels at full blast).

So, let's say then you want three booster pairs. You have 78% of the 7840 kN left to allot, distributed among six engines - that comes out to 1019.2 kN each. That one's easy - use Mainsails set at 74% thrust. So, assuming you go with the rocket cluster and the Mainsails, you've got 49.5 tonnes worth of engines.

Now to figure up fuel in each stack. Your theoretical mass is 533 tonnes - you've got 80 tonnes of payload and 49.5 tonnes of engine. I always say three tonnes for unexpected sundry crap like decouplers, nosecones and fins. So subtract all that from the theoretical mass - you have 400.5 tonnes of fuel left; dividing into seven stacks gives you just over 57 tonnes of fuel tanks per stack. Your options are partially drained S3-14400s, or a combination Jumbo64/X200-32/X200-8 - the second of which would give you 58.5 tonnes of fuel, which is close enough for jazz, and would keep your stacks to the 2.5 radial size (so you wouldn't have to waste mass on adapters and such). They'd also save you about √24,000 or so, if that's a consideration. You'd need a little more thrust to offset the extra seven tonnes of fuel but that shouldn't be a problem since we've got engines tuned down all over the place - they have room to go up a bit.

If you did go with a Twin Boar in the core, you'd have 46 tonnes of engines plus 32 tonnes of fuel in the core already. The 3.5 tonnes of fuel saved for engines comes out to an extra 0.5 tonnes of fuel tanks per stack, so not much change over what you already have. You'd need to add 25.5 tonnes of fuel to the top of the Twin Boar - an X200-32/X200-16 combo could do the job, though you'd have to drain off 1.5 tonnes of fuel from one of those two tanks. Or just go with it and up the thrust.

One other thing you might want to try is the Optimal Rocket Calculator site; it's a handy tool that will calculate the parts required to build a booster for specifications you define. It's a really handy tool when it comes to booster design.

Other than that there's not much else I can suggest. I'll plug the Procedural Fairings mod again and call it a day at this point.

Edited June 17, 2015 by capi3101

[Glaran K'erman]

Thanks capi, going to definitely check out a rocket calc it should make designing a bit less of a exercise in chance!