General small questions topic

[Louella]

I can't brain properly today, and am staring at a delta-v map, and trying to understand what it is that it is telling me.

this one: http://wiki.kerbalspaceprogram.com/w/images/7/73/KerbinDeltaVMap.png

Say I want to make a mission that will go to Minmus and return.

I get that I need ~4550 to get to orbit of Kerbin. And then ~950 to leave Kerbin orbit and get to Minmus. So to get to Minmus, the mission needs 5500 delta-v. And then to get a stable orbit of Minmus, is then 160, then 180 to de-orbit and land on Minmus.

so I'm looking at ~6000 total, to get TO Minmus.

Then what do I need to return ? 180 to get from the surface to orbit, then 160 to get from orbit to head towards Kerbin. Is that it ? The ascent craft from Minmus only needs ~350 delta-v to get onto a path that will return to Kerbin, and if it's angled into the atmosphere, then it'll land, completing the mission ?

[Anquietas314]

Louella: Yep, pretty much. Since you can aerobrake when you get back to Kerbin, you don't need to care about the ~5.4km/s needed to stop when you get there . You should probably budget more than 4550m/s for your launch to LKO though - it's pretty difficult to fly it that well; 6500 total should be just about enough, if a little tight .

[KerBlam]

This is a good dV map, the dV required for ascent is inside the bars, descent is outside.

[Anquietas314]

This is a good dV map, the dV required for ascent is inside the bars, descent is outside.

http://i.imgur.com/LpAmOn1.png

That's the same map... if you read the text in the top left corner, it says the black text (i.e. the text outside the bars) is maximum plane change deltaV. If you think about it, it takes the same deltaV to transfer from orbit A to orbit B as it does to go in the other direction, which is roughly what is shown on the map (it doesn't consider that you want to do, for example, the transfer *from* Minmus to Kerbin (low orbit/periapsis inside atmosphere) while low in Minmus's SoI; this is particularly noticeable for Laythe).

Edited January 18, 2015 by armagheddonsgw

[Louella]

Louella: Yep, pretty much. Since you can aerobrake when you get back to Kerbin, you don't need to care about the ~5.4km/s needed to stop when you get there . You should probably budget more than 4550m/s for your launch to LKO though - it's pretty difficult to fly it that well; 6500 total should be just about enough, if a little tight .

thanks I've only done small single capsule land and return missions before, but now there's all these sciencey things to do, with research labs and so on, which are way bigger.

and yeah, I'll add some reserve fuel to give a manouver margin. I've made some spacecraft in the past, where the crew had to get out and push to get Kerbin periapsis down from 71km

[Anquietas314]

I've made some spacecraft in the past, where the crew had to get out and push to get Kerbin periapsis down from 71km

Heh. Yeah, seeing as most of the time I don't bother with fancy deltaV maps and frequently forget exactly how much deltaV is needed to go to Mun/Minmus and back... that happens quite a lot for me . Flying by the seat of your pants is a lot of fun though

[Pecan]

...You should probably budget more than 4550m/s for your launch to LKO though - it's pretty difficult to fly it that well; 6500 total should be just about enough, if a little tight .

It must be pretty difficult to fly an ascent so badly you need an extra 2km/s deltaV. While 4.5km/s is tight for stock (FAR requires less), it is much closer to what even newbies (10km, then turn) can achieve in practice, than the higher figure. When designing SSTO tail-sitters for powered-landing I only aim for 4,900m/s deltaV and usually still have 100-200m/s left after touchdown.

[Kryxal]

The budget is for a Minimus mission, not just going to LKO. For that mission, note where you will be for each staging event, it's no fun if you're landing on something not meant to, to ensure enough delta-v to leave again (though it shouldn't be an issue). You also may or may not care about cluttering orbital space...

[Anquietas314]

It must be pretty difficult to fly an ascent so badly you need an extra 2km/s deltaV.

Two words: context, and "total". That is all.

[The Last Pioneer]

Two words: context, and "total". That is all.

Idk if I should ask here but... Any tips with the rescue missions? I cant manage to intercept the guy orbiting the planet, he goes way too fast. I really dont know how to do it, I try to orbit arround Kerbal more or less like the missing crew does but I dont have a clue about how to intercept him

[Newt]

Idk if I should ask here but... Any tips with the rescue missions? I cant manage to intercept the guy orbiting the planet, he goes way too fast. I really dont know how to do it, I try to orbit arround Kerbal more or less like the missing crew does but I dont have a clue about how to intercept him

You probably have not matched orbital velocity correctly, so you just zip past the target really fast. This is a hard but rewarding thing to be able to do, and it takes practice. You need to intercept them with a very slow relative velocity, staying in exactly the same plane. Try to follow some rendezvous and docking tutorials, these should help you get close enough to do a transfer.

Welcome to the forum!

[Anquietas314]

Idk if I should ask here but... Any tips with the rescue missions? I cant manage to intercept the guy orbiting the planet, he goes way too fast. I really dont know how to do it, I try to orbit arround Kerbal more or less like the missing crew does but I dont have a clue about how to intercept him

You basically want to get into an orbit that's mostly above or mostly below the target, with the relative inclination as close to 0 as possible; the orbit should be mostly above if you ended up ahead of the target in your orbit, mostly below if you ended up behind the target. After that, you should gradually drift closer to the target. Try to launch when the kerbal's around 300km from you while you're sitting on the launchpad to minimize the time it takes to rendezvous. If you get lucky you might just arrive in orbit right next to the kerbal . Don't pay too much attention to the kerbal until you're in orbit though - treat it like any other launch.

You can use maneuver nodes to see how close you'll be in several orbits' time - right click them and then the left button moves the node back one orbit, the right button moves it forward one orbit. Place one as close as possible to the target orbit and keep moving the node forward one orbit until you switch from being ahead of the target to being behind it (or vice versa); the orbit that happens in is the one you want to bring the orbits closer together.

Play around with the node until the intercept marker reads less than 1km - you can get it to 0.0 if you like, but if it's your first attempt you don't want to screw it up and smash into the poor kerbal at 50m/s - then wait until the node, burn it, then as you get close to the target aim retrograde on the navball in "target" mode. You should aim to have a relative (target) velocity of 0 m/s by the time you reach the distance on the intercept marker. Then, visually aim towards the target and use small burns (<10 m/s) to move closer. Once you can see the kerbal, use the [ or ] keys to switch to them and then use their EVA pack (R key to activate) to get to the ship.

[The Last Pioneer]

You probably have not matched orbital velocity correctly, so you just zip past the target really fast. This is a hard but rewarding thing to be able to do, and it takes practice. You need to intercept them with a very slow relative velocity, staying in exactly the same plane. Try to follow some rendezvous and docking tutorials, these should help you get close enough to do a transfer.

Welcome to the forum!

Thank you!Well I managed to land into the Mun without the building upgrade ( all orbits manual) but I cant manage to do this mission so I feel stupid .

Thing is that I wasnt going faster.... Slower either, we were at same speed... I tried to get into a lower orbit to catch him but its really hard and I guessed that I was doing something wrong... I will try again with reading more tutorials etc.

Im learning a lot with this damn game lol I love it

[Kryxal]

You don't want to match speed, you want to roughly match position and velocity ... position first. Matching speed without being near means you're not getting a whole lot closer. If you need to catch up a bit, drop your orbit maybe 2-5 km and wait a while if you want it the easy (but potentially long) way. You'll shorten your orbital period, so by the time you get back where you started you'll have caught up somewhat.

[The Last Pioneer]

Mission success. Than you guys and God bless you all

[Newt]

Congratulations! I am sure it was a relief for them to get back home.

[The Last Pioneer]

None uses this thread anymore ? Am I The Last Noob of the entire KSP comunity? Well I need some council here. I play from time to time and with slow progression but now I feel I made an huge technological jump on my game.

I have missions of building Mun or Minmus surface bases, satellites everywhere ( check) and even Orbital Stations ( also check). Thing is, the science tree is so huge that I do not know where to focus at. Should I get the nuclear LV-N Atomic Rocket Motor? Maybe Solar Panels technology ( I have deployed Satelittes with sollar panels attached to plain metal structures so far) or maybe what it seems the technology to be able to build Rovers for Mun and other planets exploration ( I really do not know what I could get from this since the current missions such as gathering data from the Mun or the Planets requiere to be on flight).

Carrier mode is so hard that I really do not want to develop the wrong tree and discover hours later that I messed up so I really ask for some council, where should my little Kerbals head to now on? THank you.

Edited February 12, 2015 by The Last Pioneer

[Mythos]

I have missions of building Mun or Minmus surface bases, satellites everywhere ( check) and even Orbital Stations ( also check). Thing is, the science tree is so huge that I do not know where to focus at. Should I get the nuclear LV-N Atomic Rocket Motor? Maybe Solar Panels technology ( I have deployed Satelittes with sollar panels attached to plain metal structures so far) or maybe what it seems the technology to be able to build Rovers for Mun and other planets exploration ( I really do not know what I could get from this since the current missions such as gathering data from the Mun or the Planets requiere to be on flight).

Carrier mode is so hard that I really do not want to develop the wrong tree and discover hours later that I messed up so I really ask for some council, where should my little Kerbals head to now on? THank you.

So you have check on satellites and station and the suface bases or visits to mun or minmus are still open? Maybe you should research something you need to fulfill these contracts and thereby getting more and more science. Maybe there is a lucky contract that sends you to a biome wehre you haven't been before and get alle the science from there... Oh well, you should invest science into getting more science, make sure you get all the experiments as soon as possible.

[jmullin09]

Use the thrust limiter

Great point, i forgot about that feature.

[WuphonsReach]

For career mode, there's 2 basic options at the start... go for space planes or go for rockets. The science tree is really not that deep, and the hardness setting is really about how much grind you want.

Orbital satellite contracts around Kerbin or Mun are going to be your bread-n-butter, so reject contracts until you get something around Kerbin with an Ap under 8Mm and inclinations of under 45 degrees. (For the Mun, it doesn't matter as much as it only costs a few hundred dV to change inclinations drastically.)

The other bread-n-butter contract at the start are the "landed at" test contracts. Those require rolling a part out to the launch pad and hitting the spacebar to stage it. Next easiest are the sub-orbital contracts which only have an altitude requirement, not a velocity requirement. Never accept a parts testing contract with both altitude and velocity requirements unless you know for sure that you can meet both conditions (only true about 20% of the time given how the RNG works).

[The Last Pioneer]

You missunderstood me WuphonReach, Im not that early in the game, Im actually in the phase of landing and building bases all over the solar system. I just want to advance carefully, afraid of a dead end. I can grind actually just by launching satellites at least atm.

Mythos thanks for answering, I think I have most of the "science" from the science tree, at least the early ones. Atm, an upgrade costs me 150-300 depending how deep I go. My concern is more are Rovers any usefull to build bases on planets surface? Should I go for the Heavy Rocketery to be able to land on other planets?

Maybe I'm just worrying too much, but the career mode doesnt let you really any " freedom " and the skill tree is overwhelming so far. Too many options and too expensive.