Kerbal Space Program

[Red October1984]

Originally Posted by NeonSamurai

I would look at two things (though slapping on some SRB's can't hurt either). How you are getting into orbit (your flight path), and your rocket's design.

Your flight path should follow what is called a gravity turn.
http://wiki.kerbalspaceprogram.com/wiki/Gravity_turn

Basically what you want to be doing is flying almost straight up for about the first 5,000-10,000 meters, then start to pitch over and gain horizontal speed. by about 25,000 meter you should be flying almost horizontally (make sure your flightpath marker stays at least 5-10 degrees above the horizon). The reason why you fly up first before turning is you want to get through the thickest part of the atmosphere as directly as possible. Flying too fast is also not a good thing (well design rockets have a starting thrust to weight ratio of about 1.2-1.4) as the faster you go the more air resistance becomes a problem. Getting that perfect launch takes a lot of practice.

I haven't quite got the gravity turn downpat yet. I don't know how to figure my thrust to weight ratio. I'm not familiar with any of these equations mainly because my high school dropped Physics in favor of Anatomy and Physiology.

I know. Terrible. MIT offers physics courses for free online...i may read through some of that stuff.

Now for rocket designs, I would suggest sticking to conventional designs. Be sure to use nose caps on the main section+any boosters. Also having multiple stages makes a huge difference. You do not want one big rocket going all the way to orbit as you will be wasting a lot of fuel hauling up empty tanks. If you want to see what i mean, try building two small rockets. one using 2 of the same fuel tank with one engine, launch it straight up, see how high it gets. then take the rocket you built and put a secondary stage in between the two tanks and fly the mission again. Even though the second rocket is much heavier because of the decouple and 2nd engine, it is capable of going a lot higher than the first rocket.

I am, however, familiar with some basics of rocket design. I've got my certification in Model Rocketry through Civil Air Patrol so i've got some basic history and concepts but nothing too advanced. I actually built a two stage model rocket. It was awesome.

As for the suggestion to use mechjeb... I wouldn't, at least not yet. Learn how to fly first before using mechjeb to automate things. Though in theory mechjeb can teach you how to do some things, it also can teach you a lot of bad habits (there are a number of things that mechjeb does poorly or needs a lot of tweaking to do properly) and it can become a crutch where one can become dependent on it. Plus I think it really detracts from the early fun of first learning how to do things.

I'm not exactly sure I want to mod the game at all. I'm pretty happy with vanilla so far.

[Oberon]

Mods wise, this early in the game I'd suggest three things.

Kerbal Engineer
- Doesn't automate anything but it does provide lots of information about your craft in both the VAB and during launch (providing certain criteria are met).

Kerbal Chatterer
- Purely cosmetic, adds random Kerbal voices to the game along with communication beeps and the like. Gives a bit of life to it.

Alarm Clock
- Think of it as an upgraded 'warp to' function. Can be very useful in later missions when you're planning to head for Duna and the like and you need to fast forward the game to a specific launch window.

In regards to finding that launch window, I suggest:
http://alexmoon.github.io/ksp/

Which will give you information in order to find the best time to head off to Duna with the least amount of Delta-V.

Happy Lithobrakings!

[Raptor1]

Originally Posted by Red October1984

I haven't quite got the gravity turn downpat yet. I don't know how to figure my thrust to weight ratio. I'm not familiar with any of these equations mainly because my high school dropped Physics in favor of Anatomy and Physiology.

I know. Terrible. MIT offers physics courses for free online...i may read through some of that stuff.

The TWR is relatively simple to figure out. It's just the ratio between the rocket's thrust and the force acted on it by gravity. You can easily find out your thrust at sea level by hovering over the engine type you're using, while the weight of your ship is your ship's mass (it's in the Engineer's Report in the VAB) multiplied by the gravitational acceleration, which is 9.81 for all intents and purposes when lifting off from Kerbin. Like so:

TWR = (Thrust) / (Mass * 9.81)

If you're under a TWR of 1 then your rocket cannot counteract the gravity pulling it down and it'll stay on the launch pad forever (or topple over and explode), so more boosters are clearly needed. As long as you're above 1 you should be able to achieve liftoff. If you're just barely above that then your acceleration might be too low and you'll lose energy because your ship spends more time pushing against gravity, but if you're much above it then you will accelerate too fast and lose energy on atmospheric drag. IIRC the point where extra gravitational drag because of a slow ascent and atmospheric drag balance out is your terminal velocity, but that's a bit hard to figure out. Anyway, you can throttle down liquid fuel rockets or limit the thrust on SRBs until you've found the optimal ascent profile.

The other thing that you should know if you want to plan out missions is Konstantin Tsiolkovsky's famous rocket equation, which is something like this:

Delta-V = (Exhaust Velocity) * In[Mass Ratio]

Your exhaust velocity is the engine's specific impulse times 9.81 and is the basic measure of efficiency when it comes to rockets (a higher exhaust velocity will mean you can accelerate while consuming less propellant). Your mass ratio is the mass of the ship with fuel tanks full divided by the mass of the ship while empty (you can set the amount of fuel in the tanks by right-clicking on them in the VAB, at which point the Engineer's Report should reflect the new mass).

Delta-V is the measure of your rocket's total ability to change velocity, which basically amounts to your fuel budget for the mission (unless you re-fuel at a station or something). If your rocket has enough delta-V for a specific mission then under ideal circumstances it would be able to perform it. For example, I believe getting to Kerbin orbit requires a delta-V of 3,500m/s nowadays, so if your rocket is capable of that (and has TWR > 1) then it should be able to make orbit. If it had less than that it would never make orbit, and if it has more to spare then it can go on to do other missions or de-orbit.

Calculating the delta-V of multi-stage rockets is unfortunately a bit of a pain, but if you want to do it then you basically need to calculate the delta-V of the entire rocket until the first stage's fuel tanks are dry, then calculate the delta-V of the rocket with the first stage jettisoned until the second stage's fuel is out and so forth until you reach the last stage, at which point you add the results together. Like this:

Δv = (Ve1 * In[M / M1e]) + (Ve2 * In[(M - M1) / M2e]) + ...

Or something...

Anyway, there are probably places that explain all this much better than I do, and naturally Kerbal Engineer would also calculate all this stuff for you as well. But if you don't want to mod the game then knowing how to calculate your TWR and delta-V along with how to execute basic orbital maneuvers should allow you to complete most types of missions without too much trouble.

[Betonov]

I thought delta v was just the change in velocity required to perform a maneouver

[Raptor1]

Originally Posted by Betonov

I thought delta v was just the change in velocity required to perform a maneouver

It is as well. The rocket equation calculates the total delta-V the rocket is capable of. Maybe I got the terminology off somewhere...

[NeonSamurai]

Originally Posted by Red October1984

I haven't quite got the gravity turn downpat yet. I don't know how to figure my thrust to weight ratio. I'm not familiar with any of these equations mainly because my high school dropped Physics in favor of Anatomy and Physiology.

I know. Terrible. MIT offers physics courses for free online...i may read through some of that stuff.

You really don't need to fully understand physics though. My suggestion is to get your hands on Kerbal Engineer (ill leave a link later on). It does most of the messy calculations for you. It can tell you thrust to weight ratio of each stage, DeltaV amounts (important, as to get into LKO or Low Kerbin Orbit, you need a minimum of 3500 DV), and a whole bunch of other things.

I am, however, familiar with some basics of rocket design. I've got my certification in Model Rocketry through Civil Air Patrol so i've got some basic history and concepts but nothing too advanced. I actually built a two stage model rocket. It was awesome.

Good that will help. One thing you may not know is the kind of engines you should be mounting. You want high thrust engines for your first stage, and medium/low thrust for your second (or third stages). Lower thrust engines tend to be more fuel efficient, particularly in a vacuum (ISP values indicate fuel efficiency, higher numbers=less fuel usage over time).

I'm not exactly sure I want to mod the game at all. I'm pretty happy with vanilla so far.

Trust me, you want to mod KSP, there are so many really awesome mods that make the game so much better.

I agree with Oberon's recomendations (other than chatterer, I find chatterer annoying after a while).

A while ago I made a post about recommended mods
http://www.subsim.com/radioroom/show...&postcount=379
It still more or less applies, though some mods are not updated any more, or there are newer better versions.


Anyhow the places to find mods are:
http://kerbalstuff.com
http://kerbal.curseforge.com
http://forum.kerbalspaceprogram.com/...lugins-Library

My key mod recommendations are:
Active Texture Management
Module Manager
Toolbar
Distant Object
Better Atmospheres
Kerbal Engineer Redux
KSP Alternate Resource Panel
Protractor Continued
NavHud
Docking Port Alignment Indicator
Kerbal Alarm Clock
Kerbal Inventory System
Kerbal Attachment System
Ferram Joint Reinforcement
TweakableEverything
Editor Extensions
SCANsat
Deadly Reentry
Infernal Robotics
RealChute
Atmospheric Trajectories
Landing Height Display
NavUtilities
RCS Build Aid
Transfer Window Planner
Precise Node
KW Rocketry
B9 Aerospace (when ever the heck it gets updated, I would avoid the large ship parts though)

All of these mods build on the KSP experience, either by adding new parts, or new features. Its also a fraction of the mods list that I tend to use

Originally Posted by Raptor1

Anyway, there are probably places that explain all this much better than I do, and naturally Kerbal Engineer would also calculate all this stuff for you as well. But if you don't want to mod the game then knowing how to calculate your TWR and delta-V along with how to execute basic orbital maneuvers should allow you to complete most types of missions without too much trouble.

Honestly with practice you can pretty much just eyeball most of it. Kerbal Engineer, though, is real handy if you want the calculations quickly and accurately (like say if you are trying to do a gravity turn the real way).

Originally Posted by Betonov

I thought delta v was just the change in velocity required to perform a maneouver

Originally Posted by Raptor1

It is as well. The rocket equation calculates the total delta-V the rocket is capable of. Maybe I got the terminology off somewhere...

Your post looked fine to me.

Originally Posted by Raptor1

Delta-V is the measure of your rocket's total ability to change velocity

This is the more accurate definition.

[Pisces]

Originally Posted by Raptor1

...IIRC the point where extra gravitational drag because of a slow ascent and atmospheric drag balance out is your terminal velocity, but that's a bit hard to figure out.

Not really. It's just a matter of bringing the entire thing up in the air and let it free-fall nose down unpowered. Then just record the velocity on the way down as a function of altitude. That's terminal velocity. So, not hard, but 'costly'. During ascent in the lower atmosphere you should stay under that speed as you rise

[Red October1984]

Originally Posted by Raptor1

Anyway, there are probably places that explain all this much better than I do, and naturally Kerbal Engineer would also calculate all this stuff for you as well. But if you don't want to mod the game then knowing how to calculate your TWR and delta-V along with how to execute basic orbital maneuvers should allow you to complete most types of missions without too much trouble.

Thanks for that. At some point, i'll print out that post and keep it. I'll try some of that stuff out.

Originally Posted by NeonSamurai

You really don't need to fully understand physics though. My suggestion is to get your hands on Kerbal Engineer (ill leave a link later on). It does most of the messy calculations for you. It can tell you thrust to weight ratio of each stage, DeltaV amounts (important, as to get into LKO or Low Kerbin Orbit, you need a minimum of 3500 DV), and a whole bunch of other things.

I know i don't NEED to understand all the physics...but I WANT to understand it.

Good that will help. One thing you may not know is the kind of engines you should be mounting. You want high thrust engines for your first stage, and medium/low thrust for your second (or third stages). Lower thrust engines tend to be more fuel efficient, particularly in a vacuum (ISP values indicate fuel efficiency, higher numbers=less fuel usage over time).

Yeah i'm pretty familiar with that concept. Fuel efficiency is important later on...yeah.

Trust me, you want to mod KSP, there are so many really awesome mods that make the game so much better.

I'll definitely do Kerbal Engineer at least. I don't want big fancy graphics mods or anything. I'm happy with basic textures. But radio chatter might be kinda cool. The game is too quiet as it is right now.

Now, for installing these mods, do I use JSGME or just straight up copy them. And will game updates screw with my mods?


------

In other news, I DID IT! Returned from orbit around 0115 this morning.

Toyed with a few designs until I decided to build a rocket similar in design to one I saw in the training scenarios. Sure enough, with a gravity turn, I made it into orbit with oodles of fuel. I'm very satisfied.

Next mission is a fly by of the "Mun" and I haven't thought much about it at all but i'm wondering how I go about that. Since I don't have maneuver nodes yet....

[NeonSamurai]

Originally Posted by Red October1984

Yeah i'm pretty familiar with that concept. Fuel efficiency is important later on...yeah.

That and you use up most of your rocket's mass just getting into orbit. As the expression goes get into orbit and you are already at least half way to anywhere else in the solar system.

I'll definitely do Kerbal Engineer at least. I don't want big fancy graphics mods or anything. I'm happy with basic textures. But radio chatter might be kinda cool. The game is too quiet as it is right now.

There really are not many big fancy graphics mods for KSP. The reason is it can be hard enough just getting the game to run for any period of time if you are running many mods with a lot of parts. Since KSP doesn't have a working x64 version, the game is heavily limited in memory usage to only 3gb or so. In fact Active Texture Management was designed to help people squeeze in more mods by making the overall game more ugly due to it compressing most of the game textures down. The ones I suggested that do improve the graphics, is better atmospheres which adds clouds and other stuff to the planets, and distant objects, which lets you see game objects that are further away than 2.1km

Now, for installing these mods, do I use JSGME or just straight up copy them. And will game updates screw with my mods?

I personally use JSGME, but there are purpose built mod management programs for KSP. CKAN is quite popular, it even downloads the mods for you I believe. http://forum.kerbalspaceprogram.com/...ackage-Manager

I don't use CKAN myself though as I tend to mod many of the mods I use, so the last thing I want is some program auto updating everything.

In other news, I DID IT! Returned from orbit around 0115 this morning.

Toyed with a few designs until I decided to build a rocket similar in design to one I saw in the training scenarios. Sure enough, with a gravity turn, I made it into orbit with oodles of fuel. I'm very satisfied.

Next mission is a fly by of the "Mun" and I haven't thought much about it at all but i'm wondering how I go about that. Since I don't have maneuver nodes yet....

Congrats A trick to getting to the mun is to get into about a 80-100km flat circular orbit, then wait till mun-rise (when the mun appears over the horizon) and thrust along your prograde vector at full power. You may want to get use to playing with your orbits before you attempt a rendezvous with the mun though.

[Red October1984]

Originally Posted by NeonSamurai

I personally use JSGME, but there are purpose built mod management programs for KSP. CKAN is quite popular, it even downloads the mods for you I believe.

I don't use CKAN myself though as I tend to mod many of the mods I use, so the last thing I want is some program auto updating everything.

I'll probably be sticking to JSGME mainly because I know that program well.

Congrats A trick to getting to the mun is to get into about a 80-100km flat circular orbit, then wait till mun-rise (when the mun appears over the horizon) and thrust along your prograde vector at full power. You may want to get use to playing with your orbits before you attempt a rendezvous with the mun though.

I'd be trying it now but i'm so tired. I've not been sleeping well lately (unrelated to KSP but it is seeming to be a factor ) and i've got to work in the morning...but tomorrow....tomorrow i fly-by the Mun.

[NeonSamurai]

The trickiest part will be trying to make the mid way course corrections, as it is super easy to get disoriented, I would just go slow with low thrust to get a feel for how the orbit is changing.

Also I would strongly suggest upgrading your tracking station and mission control to level two. Will make your life a lot easier.

[Red October1984]

Originally Posted by NeonSamurai

The trickiest part will be trying to make the mid way course corrections, as it is super easy to get disoriented, I would just go slow with low thrust to get a feel for how the orbit is changing.

Also I would strongly suggest upgrading your tracking station and mission control to level two. Will make your life a lot easier.

I think i may try it in sandbox before doing it in career.

[NeonSamurai]

Probably a good idea, or do it with a probe if you have them unlocked. You could also spend some more time trying to grab science from kerbin as every little bit can help.

Sandbox is great though for learning the ropes. You don't got to worry so much about dead kerbals or running out of funds/reputation/whatever.

I'll be fairly impressed though, if you can pull off getting to the mun and back without maneuver nodes Definitely not a walk in the park given it can be tricky enough doing it with manuver nodes.

[Gargamel]

Returning from orbit is easy. Burn retro till your orbit drops below like 50k. Then eventually you land. Some practice runs will add precision.

[Gargamel]

By pure coincidence....

The other day, I made my first rendezvous with a shuttle to a space station. I've been using the shuttle for satellite insertion and repairs and other utilities. But since I'm using a orbital refueling station around Minmus for interplanetary missions, I needed a way to get kerbals up to the reusable craft. This version of the shuttle has a crew capacity of 20. The small service/escape vehicle also docked can only hold 7, or 3 with cargo. There is a Minmus-LKO shuttle that will transfer kerbals between the two stations.

As it turns out, it was on the same day, the anniversary of Atlantis docking with Mir. STS-71 was not only the first Shuttle mission to dock with a space station, but was also the 100th manned flight by the US.