Best orbit for beginners

[Dimetime35c]

Okay I'm sorry its in tge wrong forum. i cant set pretexts using the mobile version so cant post in the right section. totally new to ksp. It's the first flight/space sim I've ever played. What is the best orbit for me to use to learn how to dock two ships? I currently use one that flies over the poles. I'm thinking this is far more difficult then if I were to use one that goes around the middle. Am I right? What's the best one to start with?

[WillHop]

Honestly as long as both ships are on the same orbit it doesn't really make a difference. However, you should really use the equatorial orbit (heading at 90 degrees) as it is more efficient and to get anywhere in KSP, having your ship in an equatorial orbit is a must.

[tntristan12]

I like to use a 150x150km circular orbit because it gives enough room to lower periapsis for rendezvous purposes. It's also low enough that it's easy to get to, and the Oberth effect will help you out on interplanetary missions.

[Crush]

The inclination doesn't really matter as long as the orbit is circular and both ships are on similar orbits. To get two ships on alligning orbits, you control the first ship, set the other as the target, and boost north/south on the ascending/descending node until both nodes have a value of +/- 0° (or even better: "NaN").

But keep in mind that a prograde equatorial orbit is the one you can reach with the least amount of fuel, so unless you have a good reason to do something different, you should always try to start your rockets on such an orbit.

Edited August 28, 2013 by Crush

[HeadHunter67]

Indeed - a polar orbit takes a lot more fuel - and if you're not good at rendezvous, you're going to use a lot more fuel trying for an intercept. I'd recommend an equatorial orbit of about 100km - it allows for room to establish a parking orbit above or below for intercepts, and leaves you with more fuel.

Blizzy78 did an in-game rendezvous tutorial you might want to try.

[DChurchill]

Some people think you should go out to like 3000km, but I think that's way overkill. I did it at 100km.

[LameLefty]

I agree with the others: a roughly equatorial orbit of around 100 - 120 km is just about the "sweet spot" to learn how to do proximity operations (what "real" space industry types use to refer generally to rendezvousing and docking). It CAN be done, easily and repeatably and without the need to use any mods, if you're willing to put in the work to figure it out. And once it sort of "clicks" in your head, it becomes easy as pie.

Edited August 28, 2013 by LameLefty

[RoboRay]

An extremely high orbit does make docking easier because of the lower gravitational gradient (ships drift more slowly relative to each other because of their slightly different orbits), but it's really not worth going all the way out there because you have to double your distance from Kerbin's center to make a 50% difference. Going from a 100km to a 200km orbit does nothing... you'd have to go up to 800km to cut the drift-rate in half. You'd need to go all the way to 2200km to cut it by 75%, and maybe half-way to the Mun to almost eliminate it.

But don't try to do it at 75km, either. In a super-low orbit, you'll find yourself dipping into the atmosphere during the rendezvous. Somewhere around 100-150km should be fine.

The simplest way to make docking easier is to turn your craft so that the docking ports point Normal to your orbit. This is 90° left or right of your Prograde vector and along the horizon. So, if you're in an equatorial orbit, you turn North/South. If you're in a polar orbit, you'd turn East/West.

This prevents the craft from appearing to rotate away from each other and circle around each other as a result of their curved path around the planet. Turning in-line with the Normal axis gives you a stationary target for docking.

Edited August 28, 2013 by RoboRay

[LameLefty]

This prevents the craft from appearing to rotate away from each other and circle around each other as a result of their curved path around the planet. Turning in-line with the Normal axis gives you a stationary target for docking.

Good advice indeed.

Only somewhat off-topic, but for people who have a real interest in this stuff, this book here gave me the best mix of technical info and non-technical narration about how NASA learned to put the math and theory of this stuff into real-world application in the Gemini program:

http://www.amazon.com/How-NASA-Learned-Fly-Space/dp/1894959078/ref=sr_1_5?s=books&ie=UTF8&qid=1377702881&sr=1-5&keywords=Gemini+space+missions

[HeadHunter67]

It CAN be done, easily and repeatably and without the need to use any mods, if you're willing to put in the work to figure it out. And once it sort of "clicks" in your head, it becomes easy as pie.

I can attest to this. Been playing about 6 weeks now, and at first I had to rely on autopilot to do my docking and rendezvous for me. Then Blizzy did his wonderful in-game Docking Tutorial mission and it really clicked for me. Rendezvous was still hard - I was baffled by his video and Manley's too - but Pebblegarden's Phoenix Project video made it crystal-clear. After watching that series, I did an unassisted launch-to-rendezvous on my second try (first one only failed because stage lock was still on from launching the target vehicle!). And now Blizzy also has an in-game rendezvous tutorial mission also.

If I can get the hang of this stuff a month after starting KSP, it can't be that hard. I won't lie - there was a lot of frustration involved when I first set my mind on doing it myself - but I made it through.

Now I'm assembling space stations in orbit without mechanical assistance and I love the feeling I get knowing I can do it.

[chrischambers]

I agree with the others: a roughly equatorial orbit of around 100 - 120 km is just about the "sweet spot" to learn how to do proximity operations (what "real" space industry types use to refer generally to rendezvousing and docking). It CAN be done, easily and repeatably and without the need to use any mods, if you're willing to put in the work to figure it out. And once it sort of "clicks" in your head, it becomes easy as pie.

I second this.

[blizzy78]

Please don't make a post just stating "me too" or "I second this." It does not add anything useful to the discussion.

[Scarecrow88]

Equatorial orbit is better than a polar orbit because, unless you launch your two ships very close together, the rotation of the planet will mean that your second ship will launch with a built in inclination plane difference. And the bigger the time gap between the two launches, the bigger that difference will become. Only when the planet has rotated 180 degrees will your launch point be under the orbit path of your first ship again. With an equatorial orbit, as the space centre lies on the equator, your launch will always be underneath the orbit of your first launched ship.

[Ampere]

I find that 100 km is a good 'parking' orbit while waiting to do something else after launch, but when I want to do docking maneuvers I tend to push both craft's orbits out to 200-250 km, due to the slower orbits. When close to the planet, over time the craft will appear to rotate relative to each other, which can be avoided using normal angles- but that's another parameter to worry about in your rendezvous.

I find that I can get the docking done in less time and will less tedium by performing the rendezvous and docking in the higher orbits since you can just point each craft at each other's docking port and close the distance without worrying (much) about orbital effects.