Science / Design Progression Stall

[_alphaBeta_]

I'm getting the hang of this game, but have a ways to go. The big problem I have at the moment is I seem limited in my acquisition of science points which seems limited by the amount of fuel I can get into orbit to go exploring. This is a normal career play-through. My standard orbital insertion rocket is perhaps over engineered /too large for this stage of the game or I'm flying it wrong, or some combination of the two. Adding more fuel to the upper (final) stage obviously just necessitates larger lower stages to haul it into orbit. I can barely get to the mun and back.

Here is a screenshot of my current design (click to enlarge): 

Here are the boosters removed and all engines un-shrouded (click to enlarge): 

Here is my tech tree situation (click to enlarge): 

On the science, I wasted 90 science pts on miniaturization thinking that I needed a docking port for rescue missions. Oops.

Anyway, on this design I have the six boosters at 80% thrust or so, and this is usually enough to approach a 80km apoapsis. I'll wait and then fire the swivel expending all three FL-T400 tanks. From there I usually have to use up to 30% of the terrier and its two FL-T400 tanks' worth of fuel to achieve a stable orbit. For an escape to Mun I usually need a deltaV of ~850 m/s and that doesn't leave much fuel to turn a Mun flyby into an orbit, back to a Mun escape, and back to a Kerbin suborbital trajectory. Is this a normal setup at this stage of the game? The remaining fuel I wind up with seems like it's barely enough to explore and earn more science. Is this upper stage too large? I can't see adding even more fuel driving even larger lower stages. Eventually I would need more than just a command module in a respectable mid to late game upper stage, no? How does one manage this? Is there some point in the tech tree that vastly opens up the possibilities of a more fuel efficient exploration of the solar system so my upper stage isn't one huge fuel tank? I realize the Mk1 crew cabin is adding considerably to the mass being hauled around, but this allows me to work some of the tourism contracts to at least stay afloat financially.

I missing some element and how to proceed. Any help would be appreciated.

[AHHans]

Hi @_alphaBeta_, welcome to the forums.

I think we've all been there where you are at the moment. One way to go on would be to download / copy existing designs from other users and use them. If that's what you want and are looking for relevant designs, then please say so. But IMHO it is more fun (and a better learning experience) to design your own rockets.

Some comments that may help you:

• The step from the larger diameter to the smaller diameter from the payload bay to the nose of the MK1 command capsule adds a large amount of drag, so better avoid that. (Putting the MK1 command capsule on top and the crew cabin below it would be better.)
• Do you actually need the crew cabin for your exploration of the Mun?
• Did you do all the experiments that are available to you already? (In particular: have you done the science junior experiments in all situations already?)
• If you use the solid fuel boosters (SRBs) to get your apoapsis to 80 km, then you are probably not doing an efficient ascent. We recently had a discussion about ascent profiles, see here: https://forum.kerbalspaceprogram.com/index.php?/topic/190914-the-launch-profile-challenge/
• You can add more stages, either in-line (so that they start one after the other) or side-mounted (that they start at the same time, but the outer stages burn out first). These stages can be SRBs or liquid fuel stages.
• If you turn on "advanced tweakables" in the settings (from the main menu) then you get to set autostruts on the parts (in the right-click menu of the parts, the PAW). ""root" and "heaviest" can have some dangerous side-effects, but "grantparent" is usually safe. That would e.g. allow you to reduce the number of extra struts.
• My general rule of rocket design is to design top-down. E.g. for a direct ascent(*) Mun lander:
  • Design the Mun lander payload first.
  • Think hard if I need everything in that lander. Is there anything that I do to loose weight without compromising the mission?
  • Design the stage that will get the lander back from the Mun's surface to Kerbin.
  • Think hard if I need everything. Is there anything that I do to loose weight without compromising the mission? Keeping in mind that I need a healthy margin in dV to correct for steering errors.
  • Design the part that will get the lander from Munar orbit to a safe landing. Do I make it an extra stage, or use the same stage that will launch me back to Kerbin? Do I use drop-tanks? (Do I have the technology for drop-tanks?)
  • Think hard if I need everything. Is there anything that I do to loose weight without compromising the mission? (You may notice a pattern here.)
  • Add the additional vacuum stages: capture into Munar orbit, transfer from Kerbin orbit to the Mun, circularizing the orbit around Kerbin. Do I use one stage for this, or do I use multiple stages? Drop-tanks? For these parts the TWR is not so important as all of this happens in orbit. (O.K. yes, the TWR can be too low so that it does mess things up, but that is rare.)
  • Add the lifter to get everything into LKO.
  • (As you can see: saving extra weight at the "top" of the rocket is important, saving extra weight at the bottom not so. Balancing weight against safety-margin is the high art of mid-game KSP rocket design.)
  • (*) "direct ascent" = everything launches in one go, there is only one main craft (crew-capsule) that will land on the Mun and return to Kerbin. No in-orbit rendezvous around Kerbin or the Mun is done.
• Once you managed to orbit: while orbiting the Mun is easier than orbiting Minmus, landing on Minmus is easier than landing on the Mun. (Well, landing in one piece.)

9 hours ago, _alphaBeta_ said:

Is this a normal setup at this stage of the game?

That's actually a fairly good design. It is definitely capable of getting into orbit around the Mun and back with dV to spare. It may or may not have just enough dV to land on the Mun and get back with optimal flying, but I was a 200 m/s or so short of getting back to Kerbin. So it should have enough dV to land on Minmus and return. (Although you may want to redesign it for that so that it doesn't topple over so easily.)

[Fierce Wolf]

Wait, is that a Tourist ship? If not, where's the science-y stuff?

A single visit to a new biome on Mun should give you a lot of science points, if you upgrade the buildings you can do EVAs too. Do this:

1) A return capsule with: MK1 capsule, an Experiment Storage on top, and a parachute. Put a nice decoupler below all that. This is a one kerbal mission, a pilot.

2) Attach a materials bay Jr, barometer, termometer and every device you have access, 1 fuel container below that, and FOUR fuel containers around it. Place landing legs on the 4 containers and a Terrier engine on the middle one (if you don't have a Terrier, 4 sparks would do). Don't forget antenna, batteries, solar panels if you have. This thingy should have 3000 Delta-V, enough for: a) brake around the Mun b) Descend c) Land d) Take off e) Go back to LKO. If you feel bold, you can have radial decouplers to get rid of dead weight.

3) Via decoupler, attach a bigger fuel container on the bottom, and the meanest engine you have (or combination of). This stage is for completing orbit around Kerbin and even help you get to Mun.

4) MOAR BOOSTERS, enough to get up to 70kms and out of atmosphere. Summed up, 3) and 4) should have 4000 Delta V. Around 3600 DeltaV is enough for a full orbit around Kerbin, and you need 800 to 870 to get to Mun.

 

 

Once you land on the Mun, have your pilot do the science and click on the Storage to save all of them for return.

Yes, there are more optimized approaches to get there, but this one is simple and it works.

Good luck!

[Zhetaan]

@_alphaBeta_:  Welcome to the happy family!

To answer your question, I think others have touched on the major issue, so I will sum it as this:  your vessel is insufficiently specialised, or else it is specialised in the wrong way.  A vessel with a crew cabin for tourism is good for tourist contracts, but not so much for early Mun landings and science missions.

Aside from the diameter change between the .625-metre Mk. I Command Pod top end and the 1.25-metre crew cabin that does you precisely zero favours, your design, as @AHHans mentioned, is a bit too reliant on the solid rocket boosters.  SRBs are great because they are cheap for the thrust they impart, but they can also show themselves to be worth what you pay in a more negative way.

While a tourist mission in Kerbin orbit does most of its work getting to the target orbit, a Mun mission does most of its work in vacuum; you'll need to tweak your design for vacuum operation.  You said that you were in the early career, but without knowing what you have unlocked in terms of facilities, I am limited in how much I can help you.  For example, you really ought to unlock EVA ability for the sake of both getting surface samples (and planting flags, which can be worth a lot of money) and for the sake of collecting experiment data, which means that you don't need to haul the experiment modules home (this saves weight and thus fuel).  You should consider, in case you have not yet done it, unlocking the higher part counts, because it's easier to manage rocket size and weight than it is to design a Mun mission that uses 30 or fewer parts.

Don't be afraid to run a few more tourist contracts to build up a cash reserve.  It takes money to make money, in this case.

Put a solar panel on your vessel.  You only need one, and the pod's internal battery is sufficient provided that you keep the panel facing the sun when in space and you don't land in the dark on the Mun.

Please don't hesitate to come back with further questions.  Definitely don't hesitate to come back with tales of success.

Good luck!

Edited January 24, 2020 by Zhetaan

[bigcalm]

Firstly - I suspect AHHans has the issue when he suggests an inefficient ascent - are you by any chance going mostly straight up and then mostly east to get into orbit?  From what I see of your rocket and payload you should easily have enough to (a) orbit and (b) do plenty of stuff whilst you're there.  However, the 6 (!) solid rocket boosters are likely to give you such a kick that I imagine your first phase is just mostly pushing you upwards and not sideways for an efficient gravity turn.

Secondly - make sure you go and get the science from everywhere.  There's "low kerbin orbit" and "high kerbin orbit" - going up to an altitude above 250k will give you a new place to sample a lot of the science experiments.  Try launching on a Polar orbit as well - lots of EVA reports add up quickly to a bunch of science points.  And finally, when you finish with that polar orbit - land back at one of the poles where it's fairly easy to hit a biome you may not have sampled before.

I have no problems with a multi-use vehicle though as others have.  I heart multi-use vessels as you can do multiple contracts simultaneously and still get the science, if you're clever about it.

[_alphaBeta_]

Thanks for all the responses. While playing after this post and before your responses, I took another look at the Science Jr since it's under research on the tech tree and I thought I may be missing something. I initially completely misunderstood what this was used for, so this was probably one of the major missing links in my progression. I had read about it, but the "materials" aspect of it in descriptions was throwing me off thinking it was only used to analyze samples. This coupled with taking a scientist along to reset them should make all the difference when my latest rocket returns from a low and high orbit around the Mun.

Thanks all for the rest of the information on design and gravity turns. I've tried a shallower ascent angle with this design with mixed results. I think it's so large that it may be better to clear a good portion of the atmosphere before really laying into the turn. Will experiment further with these references and in general. Plus, I should have more parts to play with shortly.

I had put the cabin on top of the command module to ensure the command module didn't go prograde on decent, which ends badly. Now that I have access to the advanced inline stabilizer, I don't think this is necessary anymore. Any way to avoid the command module nose diving on decent besides putting the cabin on top and using the advanced inline stabilizer in the early game?

I'm also having a strange problem of Kerbals going EVA on both my rockets and rescue junk. Is this something I'm doing?

Edited January 24, 2020 by _alphaBeta_
More info on cabin and question on EVA

[AHHans]

4 hours ago, _alphaBeta_ said:

Any way to avoid the command module nose diving on decent besides putting the cabin on top and using the advanced inline stabilizer in the early game?

A single MK1 command pod, a crew cabin, and a heat-shield (plus appropriate parachutes, solar panels, RCS thrusters, batteries, etc.) can be held straight during re-entry without the help of additional reaction wheels - i.e. with only the reaction wheels in the command pod. (With two crew cabin on a MK1 pod this doesn't work anymore.) If you set the navball to "surface" and tell your pilot to keep retrograde, then he will do his/her best to keep the heat-shield facing straight into the oncoming air. It helps if you use up any remaining fuel in your final stage to slow down (without lowering your PE too much) before re-entry.

I haven't tried if it also works if you add a payload bay into the mix, but in this case you could add a small reaction wheel in there. It does not work with two crew cabins.

4 hours ago, _alphaBeta_ said:

I'm also having a strange problem of Kerbals going EVA on both my rockets and rescue junk. Is this something I'm doing?

It probably is. (SCNR) But it would help to know what that problem actually is.

[_alphaBeta_]

2 hours ago, AHHans said:

A single MK1 command pod, a crew cabin, and a heat-shield (plus appropriate parachutes, solar panels, RCS thrusters, batteries, etc.) can be held straight during re-entry without the help of additional reaction wheels - i.e. with only the reaction wheels in the command pod. (With two crew cabin on a MK1 pod this doesn't work anymore.) If you set the navball to "surface" and tell your pilot to keep retrograde, then he will do his/her best to keep the heat-shield facing straight into the oncoming air. It helps if you use up any remaining fuel in your final stage to slow down (without lowering your PE too much) before re-entry.

I haven't tried if it also works if you add a payload bay into the mix, but in this case you could add a small reaction wheel in there. It does not work with two crew cabins.

It probably is. (SCNR) But it would help to know what that problem actually is.

Any way to do two cabins other than putting them on top again? I had a successful landing with two behind the cm using winglets to fly the command module prograde and use the winglets to create drag in the atmosphere by pulling up.

Lol, fair enough on the EVA; got a little distracted with the edit that a sentence was missed. The issue is that the kerbal leaving a hatch and hanging on the outside seems to produce a force that starts to rotate the vessel they were just in. This is happening on the "junk" the kerbals are waiting to be rescued from as well. Doesn't always happen. I've read this phantom force is sometimes the kerbal clipping to part of the vessel, but I don't see how this would apply to a single command module junk that I'm rescuing from, for example.

[AHHans]

20 minutes ago, _alphaBeta_ said:

Any way to do two cabins other than putting them on top again?

Well, my design for an early 5 person craft is: MK1 pod - crew cabin - upside-down MK1 pod - MK1 pod - heatshield

That has enough reaction wheel torque to keep upright under most circumstances, doesn't have the squishy crew cabin at the bottom where it gets hot, and has more hatches to make rescuing people easier (no need to have the pilot exit the craft to let a rescuee in). It has a strange waist, but all connections are at the same size, which keeps the drag down.

But of course other design are also possible!

27 minutes ago, _alphaBeta_ said:

The issue is that the kerbal leaving a hatch and hanging on the outside seems to produce a force that starts to rotate the vessel they were just in.

IIRC this doesn't happen (to me) when the Kerbal has something to grab to when exiting the capsule. I.e. when, after clicking on "EVA", the Kerbal holds onto the capsule. As soon as the Kerbal is free, they orient themselves in space (IIRC head to normal or to north), and that usually includes hitting the capsule (with their hands or feet or whatever), which sends the capsule spinning. On crewed parts that don't have anything to hold on to (e.g. the MK1 crew cabin) this happens immediately after going on EVA.

[Fierce Wolf]

9 minutes ago, AHHans said:

The issue is that the kerbal leaving a hatch and hanging on the outside seems to produce a force that starts to rotate the vessel they were just in.

Yes, this happens more often in light craft. Once you start putting more mass in your ships you won't notice it.

[_alphaBeta_]

Thanks for the continued info. For some reason, in my head, a vessel could have only one command module. Never thought about combining some together.

I get the vessel rotating when initiating an EVA when there is and is not something to grab on to. Seems random. At least it's forcing me to up my EVA maneuvering skills.