Spheniscine's Guide

[Spheniscine]

I have written a tutorial series here: http://www.lets-play-sphen.com/?p=218

It currently has four chapters and an appendix.

Comments and suggestions welcome.

[Pecan]

Nice job. Always good to see people writing stuff, even though Squad only ever advertises videos.

I envy you your writing. I lost count of the number of times I read mine and still found loads of grammatical and typographical errors; didn't notice any in yours, but wasn't really checking closely enough for proof-reading.

Some comments:

try out the “stock†vessels preloaded in the game (they aren’t too useful at teaching you how to design rockets in Science and Career mode, however, as they use parts from all over the tech tree).

- The stock ships aren't much use in sandbox, either. They are deliberately built 'a bit wrong' so people have to work at making them fly well (or at all). Easier to just go straight to making your own.

save your game from the building view. Note that saved games are like snapshots of the current game profile and is stored in a separate folder;

- Mention alt-F5/F9 for multiple quicksaves?

Symmetry Mode when you hover over it. If you click on it, the number of fins changes. Click it until it shows two fins (note that you can also cycle through this by pressing X repeatedly)

- Shift-X cycles backwards

Getting into orbit will require a vessel that is a little more complicated than the ones you built in the previous chapter.

- This is a very complicated ship just for orbit, but I suppose it depends on how quickly you want to show advancement.

- Explain the difference between SRBs and LF engines/tanks? Not sure that I agree about the T45 vs the T30, but in any case gimballing/rotation might be better with more explanation too.

set Thrust Limiter to 48%.

- The whole 'tweaking' thing could be explained here. Why you're reducing thrust needs some explanation.

Turn your craft slightly past the artificial horizon. Wait for your time to apoapsis to reach about 15 seconds.

- create a manoeuvre node instead of 'by eye'?

Now here comes the tricky bit: Take an Mk2-R Radial Mount Parachute, and place it carefully on top of the Stayputnik Mk1.

- use symmetry-2, place 'chutes on the pod, save more of the ship?

To do this, you will have to perform what is known as a “plane shiftâ€Â. Click on the point of your orbit with one of the nodes (pick the one that’s closer).

- 'closer' might not be right; try 'the one that comes next in orbit'?

Now pull or push the ksp-normal normal and ksp-antinormal antinormal axis to adjust your plane.

- At this point you haven't said to create a manoeuvre node, or how to.

Then point your ship to the zenith (white dot in the center of the blue half). This is because EVA’d kerbals have a preferred “up†direction, for some strange reason, and have no “roll†controls; aligning your ship to the zenith would make it easier to board.

- maybe, but the EVA preferred alignment is N/S

[Spheniscine]

Thanks for the feedback.

maybe, but the EVA preferred alignment is N/S

Not if you're in chase mode, which is the easiest to use mode for rendezvous maneuvers.

Edited November 30, 2014 by Spheniscine

[Pecan]

Hmmm, you could be right but I thought Kerbals' "heads up" was always celestial-body North? Whatever it is it's very annoying ^^.

[sal_vager]

Kerbals on EVA and flying will align to the camera

Unless you turn it off in the settings.cfg that is....

Hidden features!

[Spheniscine]

- This is a very complicated ship just for orbit, but I suppose it depends on how quickly you want to show advancement.

It's based on a design that Scott Manley used for a tutorial video, and which I have used myself for my first orbit. I don't really have any idea how to simplify it; it has 5,271 m/s of ÃŽâ€v, which is just enough to give some room for error, and all my orbital rockets are basically scaled-up/tweaked versions of this craft.

Not sure that I agree about the T45 vs the T30, but in any case gimballing/rotation might be better with more explanation too.

I find the gimballing very helpful; it allows me to save on reaction wheels/winglets, which also requires higher tech.

use symmetry-2, place 'chutes on the pod, save more of the ship?

Never had much luck with that; you need to be pretty slow to land on the engine safely. Also it makes the vessel taller and thus more prone to tipping.

create a manoeuvre node instead of 'by eye'?

I dunno; I somewhat prefer doing it by eye because some of my rocket designs would drop a stage during that burn, thus screwing up any burn-time estimate. Secondly, I'm usually not trying to be very precise there.

Edited November 30, 2014 by Spheniscine

[Pecan]

They're only suggestions for your consideration - if you don't like them then ignore them. As a whole it's good and these are minor things you might - only might - like to consider.

(Can't see how putting radial chutes on the sides of the pod instead of the top of the Stayputnik makes the rocket taller though! <-- Forget that, I re-read your comment and now understand "save more of the ship" makes it taller, not 'chute placement (see post below))

I shall look again at what science instruments you have on that ship and give you a simpler version if I can. Once more, I just read-through quickly to give you some immediate feedback as that's what you asked for; it's not a forensic report!

Edited November 30, 2014 by Pecan
Posts crossed

[Spheniscine]

Can't see how putting radial chutes on the sides of the pod instead of the top of the Stayputnik makes the rocket taller though!

I meant trying to save the fuel tank and engine would make the rocket taller

[Pecan]

Ok, first run-through without trying any tricks:

Your design = Three stage:

RT-10/T45/909 - 24.355t, 11,987 funds, 5,277m/a deltaV (1,796/2,053/1,427), TWR 2.01/2.2/1.59, <some> parts (I changed ship before checking)

If I've reconstructed properly as you described (duh! should have downloaded the .craft - it's 3am, what can I say!).

My preferred (because I don't have steering trouble with just pod-torque on such small vehicles) = 2 stage:

T30/909 - 12.39t, 9,462 funds, 4,772m/s deltaV (2,406/2,366), TWR 1.77/1.17, 13 parts.

That's using a T400 tank under the pod (for the 909) and 3xT400 for the T30 in the launch stage.

Design wisdom would divide the dV equally between the two stages or give more to the 909 as it has better Isp, but I chose to stick with low part-count (big fuel tanks) as this is a beginner's vehicle.

A lot cheaper and lighter with one fewer stages to worry about. True, it has less deltaV but you should find it is sufficient, even flown badly - 4,500m/s is the "standard" we work to (and, yes, I'd like to have at least 10% margin (=4,900m/s) but you can tweak and adjust for what you'd like)

T45/909 - 12.64t, 9,562 funds, 4,705m/s deltaV (2,339/2,366), TWR 1.61/1.17, 13 parts.

The only difference here is the engine. Note the increase in mass and cost along with the decrease in dV and TWR.

Edited November 30, 2014 by Pecan

[Kerbart]

Are you the Mousehunt Spheniscine?

[Spheniscine]

Are you the Mousehunt Spheniscine?

Yes, indeed I am.

[Spheniscine]

My preferred (because I don't have steering trouble with just pod-torque on such small vehicles) = 2 stage:

T30/909 - 12.39t, 9,462 funds, 4,772m/s deltaV (2,406/2,366), TWR 1.77/1.17, 13 parts.

That's using a T400 tank under the pod (for the 909) and 3xT400 for the T30 in the launch stage.

Design wisdom would divide the dV equally between the two stages or give more to the 909 as it has better Isp, but I chose to stick with low part-count (big fuel tanks) as this is a beginner's vehicle.

A lot cheaper and lighter with one fewer stages to worry about. True, it has less deltaV but you should find it is sufficient, even flown badly - 4,500m/s is the "standard" we work to (and, yes, I'd like to have at least 10% margin (=4,900m/s) but you can tweak and adjust for what you'd like)

Tried it out; upper stage has quite a low TWR (1.174). Did manage to get it to orbit and back, but just barely.

Thanks for the effort though.

Edited November 30, 2014 by Spheniscine

[Pecan]

Tried it out; upper stage has quite a low TWR (1.174). Did manage to get it to orbit and back, but just barely.

Thanks for the effort though.

Yes, that's called good design ^^.

It doesn't carry more than it needs. (But does have a 5% margin for error).

By the time the upper-stage is activated it doesn't need a high TWR. (People will often use a circularisation stage with TWR < 1).

You will notice that burning almost flat will raise the periapsis much faster than the apoapsis, leaving a very small circularisation burn to complete orbit insertion.

In any case, there's lots of room for flexibility. Reduce the amount of fuel on the upper stage if you want and add it to the lower. It'll be less efficient but the late TWR will be higher.

[Spheniscine]

Hmm... gotta hand it to you Pecan - you got me to think outside the box a bit. I made one for 8,387 funds (17 part count):

Upper stage: FL-T100 + FL-T200 + LV-909

Lifter stages are four stages of stack decoupler + RT-10s. Top two have been thrust-limited to prevent excessive g-loading and drag loss.

Has 5.055 km/s, therefore a big enough margin that I'm comfortable using it as a beginner craft. Only downside perhaps may be the number of stages.

[Pecan]

:-) Glad you're having fun. Again; there's nothing wrong with your original, I just thought it looked complicated for a starter vehicle.

It all depends on what you want to present, of course, but 4 stages, thrust-limiting, etc. sounds damn hard to me. It's almost always a mistake to have more than one stage of SRBs too - I'm surprised four stacks of them work. We all learn ...

[Spheniscine]

It's almost always a mistake to have more than one stage of SRBs too - I'm surprised four stacks of them work. We all learn ...

I think maybe it's because SRBs are cost-efficient but not mass-efficient (due to comparatively low ISP), so on heavier craft, the loss of efficiency through multiple stages becomes more important. Also SRBs lack gimbaling, which is also a factor on heavier craft...

The staging isn't too much of a problem since the first three are jetissoned before the gravity turn anyway...

Edited December 1, 2014 by Spheniscine

[sal_vager]

Good stuff Spheniscine, this will help, so I've stickied it for December

[Kerbart]

One of my suggestions would be to break up the fairly long paragraphs of text and add some subheaders. At the same time you can use those headers to give an overview to the reader on what's on the menu for today:

In today's episode we will focus on the following:

• Choosing a game mode
  
• Gathering Science with your first "flight"
  
• Gathering more Science
  

This is just an example, of course. It would make it easier for the reader to navigate the text, especially when (as is intended) they're following along with you. “Now where was I?†is a bit easier to answer that way!