The Kerbal Space Program (KSP) Thread

[shortylickens]

I got out and came back using both Minmus and mun. Saved a lot of fuel (which is good cuz I got back home with about .01 KG).

 

[QuantumPion]

Amateurs ...

Hate to break it to you but that is neither a slingshot nor a gravity assist. In order for a change of SOI to actually do anything it has to change your direction. Like this...

Or better yet, and to actually do something useful, this:

 

[QuantumPion]

Alright so what is the purpose of a buggy if I cant get around on it?
Are there special science reports for just being on a buggy?

In stock KSP there isn't any really, they are just for fun. The one possible use I can think of is driving to the top of a mountain before launching from Eve.

I know for a fact lander cans dont hold many reports, just one in fact. Do command modules hold a lot of reports? I'd be getting like 4 from each landing spot (soil, EVA, goop, materials).

Kerbals can hold 1 of every unique experiment/situation combo. If you want to do multiple crew reports without transmitting them, you can go EVA to take the report out of the capsule and just hold on to it. Same goes for all the other experiments. A Kerbal can hold on to all the science you can collect on a mission all by himself.

 

[QuantumPion]

Alright, I realized its going to take forever to get all the Mun biomes in one trip. Took me a whole day to finish up material and goo just for the Highlands (I kept making little mistakes on the trip).


I would like to:


1. Put a mobile lab in orbit around Mun, with morons left inside.

2. Drop off rovers with Material labs and Goo canisters from a main ship to the surface, at various biomes.

3. Drive around, pick up soil samples and science observations and EVA reports.

4. Either meet back at main Mun base, or at main ship.

5. Retrieve science and surviving morons.

6. Transmit 100 percent data OR bring it back, whichever works best.




Is this doable?

If not, how can I fix it?

(I dont have the tiny techs needed for Buggy's yet, will invest if you guys think its worth it.)

You can certainly do this, and it's fun. Although if your goal is just to get science points as quickly and efficiently as possible, it's easier to make a single lander that can land in 2-3 biomes and then return everything itself. The lab is kind of pointless in this iteration of KSP. But, if you are playing for genuine fun and you want to make a Munar space station, go for it!

 

[shortylickens]

Can fat tires take more or less abuse than landing struts?

 

[QuantumPion]

Can fat tires take more or less abuse than landing struts?

I think they can but they also weigh a lot more.

 

[JamesV]

Hate to break it to you ...

It was meant as a joke, looks cool but very little fuel savings. The best way to get to an outer planet is one long burn from a Kerbin orbit. No course corrections, and saves a ton of time.

Your first pic is from an old alpha and a bug btw. If you were able to sling around an outer planet, your orbit would be around the Sun slightly different than the planet you went around. I've tried to do that, and my results are always the same in the current version.

Your second pic isn't worth it either, if I'm looking at it right. I've tried using the Mun and other planets, and the fuel savings is minimal on these maneuvers. Like 10 seconds in a 4 minute burn. Not worth the time, but maybe a greater fuel savings with MechJeb (I fly manually).

The only worthwhile effect in using a planet are those with an atmosphere, using air-braking, and can be hard as hell; almost better off planning to use more fuel than trying it.

 

[JamesV]

Can fat tires take more or less abuse than landing struts?

All the items have a 'crash tolerance' in their descriptions, looks like the tires are much stronger, but that doesn't mean they won't break off of whatever they are attached to, so struts would probably be needed on everything if you were looking to land hard.

 

[QuantumPion]

It was meant as a joke, looks cool but very little fuel savings. The best way to get to an outer planet is one long burn from a Kerbin orbit. No course corrections, and saves a ton of time.

Your first pic is from an old alpha and a bug btw. If you were able to sling around an outer planet, your orbit would be around the Sun slightly different than the planet you went around. I've tried to do that, and my results are always the same in the current version.

Your second pic isn't worth it either, if I'm looking at it right. I've tried using the Mun and other planets, and the fuel savings is minimal on these maneuvers. Like 10 seconds in a 4 minute burn. Not worth the time, but maybe a greater fuel savings with MechJeb (I fly manually).

The only worthwhile effect in using a planet are those with an atmosphere, using air-braking, and can be hard as hell; almost better off planning to use more fuel than trying it.

Not sure what you are talking about but you are pretty misinformed. Your picture is not a gravity assist -at all-. You just went in a straight line which happened to go through the SOI of the Mun and Minmus.

My first picture is a large gravity assist from Jool that goes into a high solar orbit. It's not a bug and it's not from "an early alpha". First of all every version of this game is an alpha, and secondly that picture is from 0.21. That's how gravity assists work. What I did is basically the exact same thing the Voyager and Pioneer probes did, only difference is in KSP you can't actually escape the solar system.

The second picture is a gravity assist from Eve to get from Moho to Kerbin, with the inclination change it gives about 1000 m/s which is quite a bit. Gravity assists if planned right can give huge savings to total mission size. You can get to Moho or Jool for half the cost and make return trips to Kerbin almost free if you plan things just right or simply wait long enough. I would call those "worthwhile" savings, if you are skilled enough to take advantage of them.

 

[Revolution 11]

The second picture is a gravity assist from Eve to get from Moho to Kerbin, with the inclination change it gives about 1000 m/s which is quite a bit. Gravity assists if planned right can give huge savings to total mission size. You can get to Moho or Jool for half the cost and make return trips to Kerbin almost free if you plan things just right or simply wait long enough. I would call those "worthwhile" savings, if you are skilled enough to take advantage of them.

As a on-off player since 0.11, I can say that Quantum is completely right. Gravity assists can basically save half of the largest fuel tank (the orange one) over the mission.

My biggest problem is that if I design for a gravity-assist mission, I usually miss or botch the procedure and don't have enough fuel. If I design conservatively, on the chance of a good gravity assist, I have to dump fuel. Which is very annoying from a efficiency POV.

 

[QuantumPion]

As a on-off player since 0.11, I can say that Quantum is completely right. Gravity assists can basically save half of the largest fuel tank (the orange one) over the mission.

My biggest problem is that if I design for a gravity-assist mission, I usually miss or botch the procedure and don't have enough fuel. If I design conservatively, on the chance of a good gravity assist, I have to dump fuel. Which is very annoying from a efficiency POV.

Yeah unfortunately the tools available aren't good enough and for the most part you're better off designing a mission without gravity assists and only use them if they work out or if you run out of fuel as a backup. But I sometimes use gravity assists as a specific challenge, e.g. trying to get to Jool and back with as little fuel as possible. If I just want to go to Jool for the sake of going to Jool I wouldn't worry about it. In the case of my Moho mission above, I actually ended up running out of fuel and the gravity assist was the only way to get back home.

 

[Revolution 11]

Yeah unfortunately the tools available aren't good enough and for the most part you're better off designing a mission without gravity assists and only use them if they work out or if you run out of fuel as a backup. But I sometimes use gravity assists as a specific challenge, e.g. trying to get to Jool and back with as little fuel as possible. If I just want to go to Jool for the sake of going to Jool I wouldn't worry about it. In the case of my Moho mission above, I actually ended up running out of fuel and the gravity assist was the only way to get back home.

How do you find aerobraking vs. aerocapture? Too often, I try to use a planet's atmosphere to lose some velocity but instead I get captured into orbit and have to spend fuel to get back out. The problem here is that if I dip too low, I am stuck in orbit or a hard landing. If I dip too high, I will not slow down enough (the maneuver is not efficient enough).

 

[JamesV]

Tried it again, using a Mun slingshot (not like my pic, which I took because I never saw that before), to reach a Sun orbit outside Kerbin. Got same results I always do; doing it without the slingshot I used hardly any more fuel.

So I went and did some research, and apparently the Mun isn't worth slingshotting off of (per Scott Manley video).

Your second pic though; I didn't read that right, and now understand what you are doing. Didn't occur to me to basically orbit Kerbin and Duna for example, in a huge orbit, using Kerbin on the return journey for the slingshot (I used Duna instead, which is dumb in retrospect -burning at apoapsis).

Guess it just goes to show how deep the game can be. After 231 hours, you still learn something new. Disregard my other post.

Funny thing, the only time I've reached all the planets was doing it that inefficient way, and it didn't require massive amounts of fuel... I'm wondering if my full system explorer could reach every planet in one flight now...

 

[QuantumPion]

How do you find aerobraking vs. aerocapture? Too often, I try to use a planet's atmosphere to lose some velocity but instead I get captured into orbit and have to spend fuel to get back out. The problem here is that if I dip too low, I am stuck in orbit or a hard landing. If I dip too high, I will not slow down enough (the maneuver is not efficient enough).

Ok there are two different things here:

1) In real life there is such an idea to use a lifting body to alter the trajectory of a probe in the upper atmosphere to improve the gravity assist. But I don't think that is possible in KSP.

2) What I think you are describing is that you want to use the atmposhere to slow down relative to the planet in order to reduce your sun-relative velocity. It is not possible to get a sun-relative gravity assist in this way because the most you can reduce your planet-relative escape speed is to 0, which means the most you can do is change your orbit to match that of the assist planet. You can't get a boost, i.e. raise or lower your sun-relative speed this way EXCEPT to match orbits with the assist planet. Which is fine if you just want to aerocapture but you can't get to other planets that way.

If the free falling gravity assist doesn't give you enough delta-V you could always do a powered slingshot where you make a burn at Pe during the slingshot to maximize the oberth effect, but they can be quite tricky and difficult to do accurately.

 

[QuantumPion]

To clarify the previous point: the best gravity assist that is possible is keeping your planet-relative velocity the same (or increasing it with a powered slingshot) while changing directions by 180 degrees. Any reduction in planet-relative velocity, i.e. aerobraking or burning retrograde, reduces your potential gravity assist. See this figure:

If you aerobrake so that Uafter < Ubefore, then V + Uafter < V + Ubefore.

 

[shortylickens]

All the items have a 'crash tolerance' in their descriptions, looks like the tires are much stronger, but that doesn't mean they won't break off of whatever they are attached to, so struts would probably be needed on everything if you were looking to land hard.

Yeah but they dont all have an 'impact tolerance' in their descriptions.

 

[Revolution 11]

[lots of complicated figures and graphs]

Most of this went over my head. What I was referring to with aerocapture is using atmospheres to get into a stable planetary orbit. Aerobraking to me is a lessor effect where you are still in a solar orbit, eventually, but your velocity is lower. So if I was approaching Jool very fast and I wanted to get to Laythe, I would use Jool to aerobrake, possibly into a trajectory that intersects Laythe's atmosphere.

Now if I dip too low into Jool's atmosphere, I may get stuck in orbit around Jool or crash to the surface (whatever Jool has). I would consider this aerocapture.

By accident, I have discovered several times that using aerobraking at a specific planet can help you get to a completely different planet that would otherwise require retrograde manuevers. The fuel savings may be small but it is dependent on the situation.

 

[QuantumPion]

Most of this went over my head. What I was referring to with aerocapture is using atmospheres to get into a stable planetary orbit. Aerobraking to me is a lessor effect where you are still in a solar orbit, eventually, but your velocity is lower. So if I was approaching Jool very fast and I wanted to get to Laythe, I would use Jool to aerobrake, possibly into a trajectory that intersects Laythe's atmosphere.

Now if I dip too low into Jool's atmosphere, I may get stuck in orbit around Jool or crash to the surface (whatever Jool has). I would consider this aerocapture.

By accident, I have discovered several times that using aerobraking at a specific planet can help you get to a completely different planet that would otherwise require retrograde manuevers. The fuel savings may be small but it is dependent on the situation.

Oh never mind then I thought you were talking about aerogravity assist. What you want is something like this...

 

[shortylickens]

SCIENCE REPORT CHEAT SHEET


https://docs.google.com/spreadsheet/ccc?key=0AgOTSb5p2ZNZdGtOWFN3SzdrdGhiTUdBTTlWSVdZREE&usp=sharing


You can fill in an X or even the science value you got for each one.
Its not complete, and I dont think its entirely correct (some of those cant be got on water for example).

Anyone can edit so if you know something is definitely not available, go ahead.

Still gotta complete the two moons (they have multiple biomes each) and of course the other planets.

I suspect when the full game comes out they will probably have a way to see available research, not just completed.

 

[shortylickens]

http://wiki.kerbalspaceprogram.com/wiki/Science

http://wiki.kerbalspaceprogram.com/wiki/Biome

 

[shortylickens]

Does anybody know if you can get science reports simply from maintaining a satellite or space station in orbit?

I have the tech now (ion and large construction) but am not seeing a use for it unless theres points to be had.

 

[QuantumPion]

Does anybody know if you can get science reports simply from maintaining a satellite or space station in orbit?

I have the tech now (ion and large construction) but am not seeing a use for it unless theres points to be had.

Not in stock, but KSP Interstellar does have lab modules which get science points over time to unlock its mod specific upgrades.

 

[shortylickens]

Jesus Christ Bob stop losing so much courage each trip!

 

[shortylickens]

Alright, now I'm getting irritated.

I've gotta grab a nosecone analysis from the ground, upper atmosphere, and lower atmosphere FROM EACH AND EVERY GOD DAMN BIOME!

 

[shortylickens]

Got angry, quit for a day.
Made it to Duna. Game crashed.
BUT, loaded back up and luckily my progress was autosaved. Started right back on the surface and continued. Got soil, multiple EVA and crew reports, as much meter data as I could, transmitted a little just in case I got killed, and headed home.

Took in a boatload of points.


Just did the same tonight with Eve. But I crashed on the weird atmosphere. Managed to get plenty of science transmitted though, but without engines I was stuck.
Remote murdered the morons and will try again tomorrow.