How do you design your staging?

[Stealth2668]

Right now I use one stage to get me to about 10km, then a stage to circularize, and lastly the lander stage that goes to another planet. What about going to far planets? How do you go about that? Just wondering what more experienced people do. Also this is for career mode. Thanks

Edited August 28, 2014 by Stealth2668

[Taki117]

I usually design a three stage arrangement. First Stage get's me off the pad (Altitude varies depending on how much dV the rest of my rocket has) Stage Two will get me into orbit, Stage 3 get's me where I need to go, and everything else is payload.

[Skorpychan]

Currently, a central stack with detachable boosters and fuel tanks, and an upper stage for heavy loads. I'm currently dialing in the amount of boosters and tanks needed, though.

[cantab]

My return landings typically follow an Apollo-like pattern. Two or three serial stages on the launcher. I try and give each about equal delta-V, though I might also consider engine Isp when decided when to drop the first stage and ignite the second. I sometimes use fuel crossfeed on the upper stages to get some extra delta-V, but not on the first stage. A single stage orbiter, and a single or two-stage lander (or landers) as appropriate.

[Jouni]

I basically have four categories of vehicles: launchers, ships, shuttles, and fuel tankers.

• A launcher lifts the payload (a ship, a part of a ship, a shuttle, or a fuel tanker) to orbit or to Kerbin escape trajectory. With stock aerodynamics, I prefer using two vertical stages and two side boosters. The boosters are usually quite big, with burn times from 90 seconds to 180 seconds. With FAR, reaching orbit is so much easier that I usually skip the upper stage.
  
• Ships do the interesting stuff. They are usually designed to be completely reusable, and rarely ever return to Kerbin surface. Once reaching the target, a lander usually separates from the ship. Alternatively, the ship itself may land on the target planet, after leaving excess fuel tanks and other modules in orbit.
  
• Shuttles carry crew between Kerbin and ships in its orbit.
  
• Fuel tankers refuel returned ships for new missions.
  

[mhoram]

Usually I design my stages top to bottom.

Currenty I use the following approach.

- the payload gets fuel and engines that can bring it from LKO to it's destination with a reasonable TWR of ~0,3 - 1,0 (depending on burn times) and add 10% fuel for errors and additionally 300-500 m/s for circularizing the launch

- then add 1-2 serial stages that have together ~3000 m/s Delta-V for the upper part of the launch with a TWR > 1,5

- add an additional radial booster stage with Solid-Fuel booster that ignites together with the next stage and that adds enough Delta-V to reach orbit.

I aim for 4500-4700 m/s Vacuum-Delta-V for the lifter stages. This is enough so that the upper stage can circularize but not too much so that they don't end up as space junk.

Also if the target destination requires additional staging, I try to time the stages in a way that leaves no space junk.

My Lopac Lifters are a little bit too expensive for career mode since they don't use Solid Fuel Boosters.

[juanml82]

My basics are usually as the OP described:

A radial set of SRBs (one or two dozen of them depending on payload) to help lift the craft to 10,000 m

A booster stage which usually starts with the rockets to kickstart the velocity but I then lower the throttle until the rockets are gone. With the new SLS parts aspargus isn't needed unless the payload is too big. However, this stage might be using crossfeed or a combination of different engines which means I'm dropping some in the upper atmosphere (say, a couple of LFBs accompanying a KR-L2)

The upper stage, made to boldly go wherever I want to go. The booster stage may have enough fuel left to make a first burn before I drop it to attempt to return it safely to the KSC. What this upper stage is depends on the mission.

For interplanetary missions, it's usually a fully controllable unmanned vessel centered around an orange tank and a couple of nukes radially mounted (by making an L with girders). Some lander (or landers if I'm going to Jool) gets docked to it.

I've discarded that approach in my latest Laythe lander. The lander is going to Jool on its own power because I didn't like the long burn times of nukes. It will be circularizing the orbit with the last drops of fuel though, so the orange tanks with nukes which I send separately will have to RV with it on Jool's orbit and refuel it or that ship isn't going anywhere. Assuming, of course, that the fuel I have left is enough to circularize.

[EdFred]

Depends how heavy my final stage is and where I'm going with it.

[Stealth2668]

Very helpful tips, thanks. Does anyone have a link to that DV chart by any chance? Or perhaps a more updated one? (if things changed)

[Drew Kerman]

I design each stage separately for accurate dV without having to deal with Engineer or VOID getting confused by staging. Each stage is designed for a specific mission use from top to bottom. Mainly similar to what others have posted here (boost off pad, lift to orbit, transfer to wherever). More details in this guide I wrote up last week (including dV chart)

[Zylark]

It all depends upon the job to be done.

For getting off the ground most my boosters are based off a central core, to which extra oomph is attached radially and dropped as they run dry. I tend to go wide rather than tall for stability. Usually I get to orbit in three stages. 1st Stage is SRBs, 2nd stage are attached LFO + engines (gets me to roughly 25km) and last central stage do the rest plus circularizing the orbit at LKO - with a smidge of fuel to spare to de-orbit the stage.

In my current career I have four such boosters, for up to 6Tons, 20Tons, 40Tons and 60Tons. Only the first is a vertical design, the others are radial. The 60Ton is a full on Asparagus set-up (Core + 6 radial LFO dropped two at a time + 6 SRBs attached to the last pair).

For getting to other celestial bodies, unless really early in the career I tend to assemble whatever is needed in orbit, and then get going. Right now for instance, I'm in the planning stages to go to Duna with a lightweight manned mission, three Kerbals there, land one and get back to Kerbin again. All the stuff needed is built in the VAB, then split the thing roughly in half for getting it to orbit in two launches. Once in orbit the two halves will meet up, well actually the second will catch up to the first, and then the assembled vessel will get fueled.

The big cost in career mode is getting stuff to LKO. So having a reusable infrastructure of bases, stations, resource gathering (Kethane or Karbonite) and vessels to truck stuff back and forth is key to not going bankrupt. Sending up a dry module with a mass of 15Tons is a lot cheaper than sending up a wet module at 40Tons...

[AlexanderB]

Since carreer mode, I either use SRB's (because cheap) on the tinyest of launches, or SSTO's (because cheap and re-useable, no parts are lost). The turbojet is a big part of most of my current missions, it just saves so much fuel to get to LKO, haha.

Before carreer mode, I had aspargus on everything, but not anymore, except for my Eve return vehicle, which has something like 7 aspargus stages with mostly aerospikes.

I even found a way to lift a full orange tank into space using less than an orange tank worth of fuel. (Jet-assisted SSTO rocket, no wings.)

[Pecan]

I wrote 109 pages of tutorial about it (link in the signature)! Relax - the re-edited version isn't that long.

(It's only 101 including appendix).

[mhoram]

Very helpful tips, thanks. Does anyone have a link to that DV chart by any chance? Or perhaps a more updated one? (if things changed)

Pick yor poison ;-)

• A more accurate delta-v map
  
• http://wiki.kerbalspaceprogram.com/wiki/Cheat_Sheet
  
• http://forum.kerbalspaceprogram.com/threads/25360-Delta-V-map
  
• http://forum.kerbalspaceprogram.com/threads/20993-Request-Delta-V-maps?highlight=delta (incomplete)
  
• System Delta-V Maps by JellyCubes V0.18.4
  
• A Delta-V Map for simple flightpaths
  

I prefer the first one.

[Stealth2668]

Looking at the dV chart, to get to Jool you need roughly 25,000 dV to get there. Should you build a massive rocket or do you have refuel points in orbit along the way?

[Alshain]

For me it depends on what I'm doing. Right now I'm building a Karbonite processing orbital station around the Mun, the launcher for each component (which often is two components in one) is a mainsail and orange tank on the first stage, this gets me to about 35-40km, the second stage is the delivery vehicle, it establishes orbit, gets to the moon, rendezvous, and dock (possibly twice). That stage is the half size tank (half the orange tank capacity) a poodle, a small battery and a few of the small panels, a probe and some small amount of Monoprop/RCS.

Keep in mind I use NEAR, so it's not quite a big as you need for stock. I also do very efficient launches (by the time I hit 70km apoapsis, my periapsis is about 40-60km)

Edited August 28, 2014 by Alshain

[cantab]

Looking at the dV chart, to get to Jool you need roughly 25,000 dV to get there. Should you build a massive rocket or do you have refuel points in orbit along the way?

That figure is what you'd need to ascend from a "landing" on Jool and return to Kerbin. To just encounter Jool you only need to go up to the Kerbin-Jool transfer. Then you can get into a closed orbit by aerocapturing at Jool or Laythe, or catching a gravity assist from Tylo, Laythe, or maybe Vall, or with an engine burn close to Jool to go to the "capture/escape" stage.

[mhoram]

Looking at the dV chart, to get to Jool you need roughly 25,000 dV to get there. Should you build a massive rocket or do you have refuel points in orbit along the way?

I believe you misunderstand the map. 22.000 m/s is needed for the transfer between Low-Jool-Orbit and Jool-Ground. But since Jool has an atmosphere, landing is much cheaper.

However due to Game Engine restrictions do not expect to survive a landing on Jool.

In order to bring a ship from Low-Kerbin-Orbit to Low-Jool-Orbit, much less Delta-V is needed according to the map: around 4900 m/s if you don't use aerobraking and gravity assists.

And this should be doable without refuelling and even with a reasonably small ship.

[capi3101]

I'm like some of these other folks; I'll pick the type of staging I'll used based on the job to be done, and usually the mass of the payload factors heavily into it. If I can get away with it, I prefer to do things dual-stage (i.e. payload-booster, with the booster covering as much of the 4500 as possible). Really light stuff I might do single stage (as in no seperations whatsoever except for launch clamps - useful for things like Kerbin-orbiting temperature probes for moola; probably could do that for Mun and Minmus too with a bigger tank/engine combo). I still prefer to resort to asparagus for heavier things, though with the economics that's definitely less viable of an option than it has been in the past (and so far in my career game nothing that massive has been necessary as yet).

[Mitchz95]

Stage 1 has roughly 3000m/s and a TWR between 1.5 and 2 to get me through the thick part of the atmosphere. Stage 2 has 1500m/s and a TWR of about 1.5. That's usually enough to get me into orbit, and my transfer stage has whatever is needed to get the lander to my target's orbit and back.

[Rusty6899]

I rarely need more than 2 stages to get into LKO, and for light crafts it is doable in a single stage (due to vastly overpowered large engines). Normally, I design my stages so that they run out at a particular milestone, e.g. if I am going to Moho, I'll try to make one stage finish after my ejection burn from LKO, so that I have a good idea of how much fuel I have left relative to my expectation. I manually calculate delta-v so, after I launch, I only know exactly how much delta-V I have at the moment of each discrete stage. It therefore helps to get this information at the same point at which I know how much delta-V I need for the rest of my mission.

[Frank327]

Without noticing I've been using the same basic design for quite a while now. The landers are a central stack with capsule/fuel/engine/electricity, with two side stacks with all the landing/science equipment and as much fuel + engine as I need. They're designed to depart from LKO, I usually detach the two side stacks when I take off from my destinatin.

The stage to get to LKO is again three stacks of liquid fuel + engines. Attached to that is six solid fuel boosters on the side to get to 10km height. If those six aren't enough, I put a booster under every stack (9 stacks in a 3x3 square).

[nadreck]

With the new economics I am trying to always build a 1st stage that is pretty close to SSTO for the payload so that I can be sure of recovering it and getting at least 50% of the costs back. So the full vehicle weight ratio to the empty weight of 1st stage plus subsequent stages is generally between 4 and 5.

Also I am a huge proponent of assembling expeditions into 1 or 2 vehicles for the interplanetary transfer so, about 9 out of every 10 launches is bringing up the parts for something or fuel. Every part that I might separate into its own unit is equipped with a automatic control pod. This makes eventual docking and re-integrating much more convenient. Almost everything gets sent up without crew too. The most senior kerbonauts (Bill, Bob, and Jeb) are quite busy and take more junior staff with them, but they get the first choice at the best missions, but they don't hang around while the expedition is being put together. I would like the ability to upgrade some of the other kerbonauts to that elite, orange uniform, status.

[Geschosskopf]

Right now I use one stage to get me to about 10km, then a stage to circularize, and lastly the lander stage that goes to another planet. What about going to far planets? How do you go about that? Just wondering what more experienced people do. Also this is for career mode. Thanks

It's just like going anywhere else. Always start with the payload because on this all else depends. First, decide what the payload's job is, like land on Duna and return with 2 each Goo and Material bays plus whatever other science you can do. Having thus spec'd out the payload, design and build it to meet the specs. Now it's simply a question of providing sufficient motive power and there you have many options depending on what all else you want to accomplish. For a Duna trip, you can have anything from a bigger version of your Mun rocket and flying it the same way so the lander gets itself home. Or you can have a mothership and leave the lander at Duna for future use, and many other things. It only depends on your ambitions.

As to the staging, however, that depends on 3 things: 1) the mass of the payload, 2) where you're sending it, and 3) what mods, if any, you're using. Some mods have such big rocket parts that you can, with a sufficiently light payload, do a single-stage-to-Duna thing. But there are also things like FAR/NEAR and Deadly Reentry that make you build rockets within some constraints as to their shape. FAR/NEAR, for example, like long, tall, skinny rockets so asparagus, while possible, isn't the end-all and be-all it is with stock air.

When I use FAR/NEAR, I therefore tend to make vertically staged rockets. Usually there's a stage that gets it off the ground and up a good ways, sometimes with the help of SRBs. Then there's another stage to finish reaching altitude and circularizing. Then there's a transfer stage which may or may not be big enough for a round trip. Then there's the payload with whatever engines it needs.

[Tank Buddy]

I generally use my sub-assembly launch stages, which consist of a core rocket with a single set of liquid boosters and additional SRBs if needed. The next stage is the transfer stage which I use to circularize my Kerbin orbit (I design my launchers to have just short of the needed Delta V for orbit). Next would be the payload of a lander, rover, or probe. I also sometimes put the 1.25 or 2.5 meter probe cores on the launch stage if I plan to use it to circularize, in which case it has a little more Delta V so it can get into orbit and retroburn to have a Perikee of ~35 Km

Of course, if I launch unusually large payloads I may use MOAR BOOSTERS!