how to get past 5k?

[Troubletcat]

This wonder took Val and Bob to Minmus and Mun orbits, where Bob did his EVA walks to the science lab and experiments in that service bay, taking data and resetting experiments every time.

Yes, that's asparagus staging. Fuel lines are well worth it. Note that you need to upgrade astronaut complex to get EVA, which is a must and should be attempted as soon as you can do orbit. Tracking station, VAB and launchpad also upgraded.

Netted over 600 science this way.

http://i.imgur.com/BwqRKwe.png

P.S.: If you're looking for parachutes, they're tucked away in the service bay. Just open the bay to deploy them. I also have extendable solar panels in there as well as the rest of experiments (goo canister, thermometer, barometer).

Nice! 600 science from one mission for 36k!

[Mipe]

I'm a bit strapped on cash now, though, as you can see. Thanks to KSP crashing when my experimental rocket crashed, not letting me revert. Those tourist contracts don't give any advance. Guess I'll have to cash some of that science in... Or take a single tourist on a SRB-strapped rocket. Or decline contracts until I get one with advance payment. Hm.

The SRB space bus sounds fun!

[NeoMorph]

@jwenting

That damned tumble... I had it happen to me again since the 1.0.0 launch. The cause is similar to the max-Q problem (ie the point of maximum dynamic pressure between the spacecraft and the air). As you are trying to go faster you are trying to push through a brick wall of solid air. Think of how fluid water is (pun unintended) yet if you hit that water going at high velocity it may as well be bricks. In your case the hint is the vapour coming off the canards and tail fins... and with that air pressure coming up against that big egg at the top it is forcing the craft to tumble. I found out that half my designs I used to put sats into orbit did the same thing.

You could probably use a narrower protective shell which would help a lot. But throttling back as soon as you see that vapour until it vanishes and then keep throttling up bit by bit as the air density drops and you will find the rocket stays more stable.

[Aerindel]

I had a little trouble with rockets tumbling but then I put fins on them (never needed them in .90) and all is good, and now that I've had a few days with 1.02 I don't even need fins any more. I find its best to turn about 5º east immediately at launch and then at about 10k throttle down until you are barely accelerating and the nose will just tip right over nice and slow, by the time it reaches 45 you should be high enough to be out of the danger zone and you can go max thrust and aim for the horizon. If your rocket is built right you can do this all without SAS or maneuvers, (except the first 5º turn), just let gravity swing you around and use the throttle to control heading.

BTW, I think your problem with that first rocket is the massive fairing at the nose. That thing is huge and will cause a lot of drag. The idea with fairings is to fit them as close as possible to your payload, I don't even worry about a pointy nose, blunt is fine, maybe even better, and if you look at real life rockets they almost all have round noses, not points.

[Chaos_Klaus]

Hm ... to get back to the original post:

The engine is way heavier than your payload. Thus, your center of mass is moving towards your engine while you are emptying the tanks. That means it will be behind your center of drag and will tend to flip you around 180°.

Use fins to prevent that. The problem is also reduced if you add more weight to the top of the rocket. However that sometimes isn't an option.

[Troubletcat]

Fairings serve another purpose: they protect your payload from burning up due to overheating during ascent.

If that's happening with regular rockets like the one you showed, you're going too fast too low in the atmosphere anyway. Go slower until you get higher up.

[pellinor]

Hm ... to get back to the original post:

The engine is way heavier than your payload. Thus, your center of mass is moving towards your engine while you are emptying the tanks. That means it will be behind your center of drag and will tend to flip you around 180°.

Use fins to prevent that. The problem is also reduced if you add more weight to the top of the rocket. However that sometimes isn't an option.

Another small fix is to pump fuel from the lower to the upper tanks, so your CoM stays in the front while moving through the lower athmosphere.

[LameLefty]

You guys are massively over-building for very simple missions. This one has 26 parts, 29.1 tonnes, costs <14,700 funds, has 5,900+ m/s vacuum dV, and will orbit the Mün and return. Do a few EVA and Crew reports, land on a different Kerbin biome on return, expose your Goo high over the Mün and low - plenty of Science!™ return for a simple mission.

The boosters and core are powered by gimbaling engines so no need for fins if you fly a proper trajectory. The boosters ground start, the central core starts at staging. Works a treat. You could add two more radial boosters if you want to lift heavier payloads at the expense of cost of course.

[Troubletcat]

You guys are massively over-building for very simple missions. This one has 26 parts, 29.1 tonnes, costs <14,700 funds, has 5,900+ m/s vacuum dV, and will orbit the Mün and return. Do a few EVA and Crew reports, land on a different Kerbin biome on return, expose your Goo high over the Mün and low - plenty of Science!™ return for a simple mission.

The boosters and core are powered by gimbaling engines so no need for fins if you fly a proper trajectory. The boosters ground start, the central core starts at staging. Works a treat. You could add two more radial boosters if you want to lift heavier payloads at the expense of cost of course.

http://i1342.photobucket.com/albums/o777/LameLefty/Odds%20and%20Ends/screenshot262_zpsdhfhrrn4.png

Yeah, see... that's what I said. The pics in this thread just seem hugely overbuilt. This is similar in costs to my rocket for that mission, but a little different design.

[NeoMorph]

You guys are massively over-building for very simple missions. This one has 26 parts, 29.1 tonnes, costs <14,700 funds, has 5,900+ m/s vacuum dV, and will orbit the Mün and return. Do a few EVA and Crew reports, land on a different Kerbin biome on return, expose your Goo high over the Mün and low - plenty of Science!™ return for a simple mission.

The boosters and core are powered by gimbaling engines so no need for fins if you fly a proper trajectory. The boosters ground start, the central core starts at staging. Works a treat. You could add two more radial boosters if you want to lift heavier payloads at the expense of cost of course.

http://i1342.photobucket.com/albums/o777/LameLefty/Odds%20and%20Ends/screenshot262_zpsdhfhrrn4.png

You probably forgot Jeb's instructions... "If at first you don't succeed... ADD MOAR BOOSTERS!".

I bet everyone when they started used to use Jeb's rule when instead they should have been looking at the Thrust to Weight Ratio (TWR) when getting to orbit and Delta-V when going interplanetary. I used to use this cheat sheet (see below) but don't know if it's valid for 1.0.0+.

Edited May 3, 2015 by NeoMorph

[jarmund]

okto+nosecone +fuel tank + reliant (gimbaled). can't be any simpler. Latest Mechjeb dev build can't handle it either

is 1.0.2 working for anybody? need a reality check here.

Working fine here, as I just returned a three-man capsule after a minimus trip.

What you need is a set of finns near the engine, as they make everything better. As the reliant does not have vectored thrust, you might want to consider some finns that move.

[NeoMorph]

Another thing I forgot about is something I do for most craft. I turn off the gimballing for some of the rockets to stop them going extra twitchy or bonkers with the flipover. I had one happen like that just this afternoon. Fix was to leave the centre rocket gimbal free while I locked the others until I got above 30k.

A lot of it is just trial and LOTS of errors lol.

[Mister Spock]

Do fins help? With a simple two-stage rocket, with gimbals on the lower stage, I seem to have more flight control without fins. Not great, but at least it goes up mostly straight. Most of my designs with fins seem to want to turn west, which is just the opposite of what I want them to do. Then again, I have only the basic fin and the next fin up, not the fancier AV-R8 or whatever they're called.

And yeah, I need a bit moar delta-V than that. Is 4550 m/s still the ballpark figure, as the above chart suggests? I've heard people mentioning figures quite a bit lower.

[Troubletcat]

Do fins help? With a simple two-stage rocket, with gimbals on the lower stage, I seem to have more flight control without fins. Not great, but at least it goes up mostly straight. Most of my designs with fins seem to want to turn west, which is just the opposite of what I want them to do. Then again, I have only the basic fin and the next fin up, not the fancier AV-R8 or whatever they're called.

And yeah, I need a bit moar delta-V than that. Is 4550 m/s still the ballpark figure, as the above chart suggests? I've heard people mentioning figures quite a bit lower.

No. It's more like 3500m/s now, but I don't have the exact figure.

When it comes to fins, I've found they do help, but it depends on where you place them. Try putting them right near the bottom of the rocket and use 3-way symmetry so that one is pointing straight "up" (i.e, west on the launch pad. Check the first screenshot in my post on page 2, you'll see what I mean). This tends to work very well for me in combination with the LVT-45 gimbal and the pod torque, generally have pretty good control as long as the rocket isn't very long or wobbly or just going way too fast near the ground.

Edited May 4, 2015 by Troubletcat

[r4pt0r]

This one has 26 parts, 29.1 tonnes, costs <14,700 funds, has 5,900+ m/s vacuum dV, and will orbit the Mün and return. Do a few EVA and Crew reports, land on a different Kerbin biome on return, expose your Goo high over the Mün and low - plenty of Science!™ return for a simple mission.

I am stealing that, I always overcompensate.

[Rickenbacker]

Working fine here, as I just returned a three-man capsule after a minimus trip.

What you need is a set of finns near the engine, as they make everything better. As the reliant does not have vectored thrust, you might want to consider some finns that move.

Damn, i was about to make a joke about the finnish, but you beat me to it .

In any case, getting your CG high on the rocket is better than fins - it doesn't cost you any extra weight/drag, and it auto-stabilizes the rocket during ascent.

[Mister Spock]

When it comes to fins, I've found they do help, but it depends on where you place them. Try putting them right near the bottom of the rocket and use 3-way symmetry so that one is pointing straight "up" (i.e, east on the launch pad. Check the first screenshot in my post on page 2, you'll see what I mean).

Ooh, thanks for the suggestion. I assume "east" in the VAB is the portion of the rocket facing outdoors? It's a little hard to tell from your screenshot.

Also, in the VAB editor, I have trouble fine-tuning the facing of stuff like this. Is there a hotkey that can give me finer control?

[BagelRabbit]

If I may leave this here: A Simple Guide to Rocket Aerodynamics!

This really covers just about all you need to know about rocket stability. If you read this guide carefully, you should be able to construct rockets that are aerodynamically stable and very pleasant to fly!

-Upsilon

[Troubletcat]

Ooh, thanks for the suggestion. I assume "east" in the VAB is the portion of the rocket facing outdoors? It's a little hard to tell from your screenshot.

Also, in the VAB editor, I have trouble fine-tuning the facing of stuff like this. Is there a hotkey that can give me finer control?

Whoops, I meant to say west, not east, but yeah, the door is on the east side of the VAB. Basically one fin should be pointing up after you've turned east off the pad. If that's still not clear take a look at the video I posted on page 3, where I actually fly the thing.

Sometimes more than three works better. Really depends on the rocket. But that's generally my go to configuration.

If you're using angle snap it should be a breeze to get it on the right angle (since one of the directions it'll snap to is the correct one).

Edited May 4, 2015 by Troubletcat

[Mister Spock]

Great guide, Upsilon. It helped a lot!

OK, I did make it to orbit simply by re-orienting my three fins slightly, so that one points directly east and the other two NW and SW respectively. What a difference! Now the rocket "wanted" to tip east rather than west, which is what we want. Er, I imagine that's because two fins on the "west" side create more drag than the one fin on the "east" side?

Also, what do the blue and red drag indicators on F12 mean exactly? I assume red means drag, blue lift? I did a quick Google search but I'm still not entirely sure.

Finally, which is the important delta-V readout in KER? I see 2380/4437 m/s in the summary delta-V screen. I gather the first number is in-atmosphere delta-V, the second vacuum? I got to orbit with just 50 m/s delta-V to spare, so does that mean I needed 4387 m/s delta-V? If so, I seem to be a lot less efficient than people who are reaching orbit with 3500 m/s delta-V.

- - - Updated - - -

Whoops, I meant to say west, not east,

Oh! I did just the opposite of what you suggested, and yet I still had better ability to turn east, and I did make it to orbit. I put one fin facing east, not west.

I'll try re-orienting now, with just one fin facing "west", to see if I do better.

[X-SR71]

Great guide, Upsilon. It helped a lot!

OK, I did make it to orbit simply by re-orienting my three fins slightly, so that one points directly east and the other two NW and SW respectively. What a difference! Now the rocket "wanted" to tip east rather than west, which is what we want. Er, I imagine that's because two fins on the "west" side create more drag than the one fin on the "east" side?

Also, what do the blue and red drag indicators on F12 mean exactly? I assume red means drag, blue lift? I did a quick Google search but I'm still not entirely sure.

Finally, which is the important delta-V readout in KER? I see 2380/4437 m/s in the summary delta-V screen. I gather the first number is in-atmosphere delta-V, the second vacuum? I got to orbit with just 50 m/s delta-V to spare, so does that mean I needed 4387 m/s delta-V? If so, I seem to be a lot less efficient than people who are reaching orbit with 3500 m/s delta-V.

- - - Updated - - -

Oh! I did just the opposite of what you suggested, and yet I still had better ability to turn east, and I did make it to orbit. I put one fin facing east, not west.

I'll try re-orienting now, with just one fin facing "west", to see if I do better.

No, usually the first is the stage's dV and the second is total up to that stage.

Also, you mustn't forget that dV's shown in KER when the atmosphere button is toggled considers sea level at default. You probably have a little more of 2380 total dV for your atmospheric stage, since engine's ISP tend to improve with altitude.

I've been using 2000dv for the atmospheric stage and 1000dv more for circularization (fires up at 45km or so). Tends to work..

Red is drag, blue is lift, but yellow beats me.

Edited May 4, 2015 by X-SR71

[Mister Spock]

Oooh, thanks; I've been mis-reading KER. I think I did know that once, lol; it's been a while since I've played. Off to look at it again.

Edit: OK, I think I mostly get it. I just now made it into orbit, and back to Kerbin, with plenty of fuel to spare. I have more questions about KER, but I'll go ask those in the KER thread.

Edited May 4, 2015 by Mister Spock