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hello, changing orbit trouble


dramabeats

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new guy here, I've figured out how to get into orbit and how to change the max and minimum height by throttle at the prolapse and vice versa.

I've tried numberous times to change my orbit using those manuvers and it never works, I do the '50/50' burn. For instance if the burn time is 7 seconds then I burn for 14 on each end.

any good guides on getting to the mun?

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new guy here, I've figured out how to get into orbit and how to change the max and minimum height by throttle at the prolapse and vice versa.

I've tried numberous times to change my orbit using those manuvers and it never works, I do the '50/50' burn. For instance if the burn time is 7 seconds then I burn for 14 on each end.

any good guides on getting to the mun?

Circularizing the orbit works best at the Apoapsis, or high end burning parallel in the direction you are going, or Periapsis, low end burning parallel against the direction you are going. You can also use the Add Maneuver tool to plan those burns and find how much time is needed to complete the maneuver. Note, it doesn't take much thrust to alter the altitude of the orbit once in orbit. it takes a lot more thrust to alter the orbital plane, applying thrust at an angle to the direction of travel in orbit.

As for planning a Mun maneuver, the same tool can be used to plan for the encounter. It will show up as an altered path when you get it in the right location by moving its location and adjusting the handles, then your goal is to fine tune for the most efficient burn to get there. Look for the tutorials on how that is done.

As in all maneuvers, the Ball at the bottom of the screen is your most important navigation tool to visually show you where your spacecraft is pointing relative to the markers showing the prograde or retrograde of the direction your ship is traveling and where your ship is actually pointed in relation to the horizon of the body you are orbiting.

Edited by SRV Ron
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throttle at the prolapse...

Ahahaha! Stop straining, it'll come easier.

Anyway, the 50/50 burn means that you divide the burn time by two. So if your burn time is 14 seconds, you should start 7 seconds early (start at T-7s and finish at T+7s).

Your OP indicates you are multiplying the burn time by two and then doubling it again.

Edited by TMS
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SRV you lost me at altered path.... this game is difficult lmao

Sorry about being too technical. Start out slow. I did with a suborbital crafts, then added a second stage and following the advice of how to do the gravity turn, got my two stage design into orbit with enough fuel left to bring it back down safely.

To raise the lowest point of the orbit, wait until your spaceship is almost at the highest point and pointing directly in the direction of travel. Use the Nav Ball to orient the ship correctly. Do a short burn and check the lowest point to see if it went up. Do the opposite for the lowest point to bring the highest point down - in that case, you burn against the direction of travel. Pointing the ship up or down or left or right will use excessive amount of fuel to get the change.

In orbital mechanics, real space flight or the KSP simulator, the shortest path to a destination is always a curve since everything, Kerbal, Mum, your spaceship, is always moving and under the influence of gravity. And, it is in 3-D. So, if you didn't launch into orbit heading due east, your orbit will be in a different plane then Mum.

When planning the maneuver for an intercept to Mum using the add maneuver command and moving the handles, your orbit will become elliptical. When that path comes under the influence of Mum's gravity, you will see the path being altered. That is what you are looking for. Fine tune the maneuver location and handles to get the most efficient Mum encounter possible. Again, if you are not sure how it is done, go review the tutorials, then experiment on your own.

Experiment to see what works and what doesn't. This is how you will learn how to control a space craft in orbit. Soon, you will become an expert and be ready for something more challenging. If totally stumped, go to the tutorial videos and try what others have done successfully.

Keep in mind that during the days of Apollo, the flight engineers had to calculate orbital mechanics with slide rules and computers so primitive that they had to be programmed with a hexadecimal keypad for every maneuver executed during flight. There was no KSP for them to train on.

BTW, I has set up a very efficient Mum encounter with a 12 second burn which would have place me close for an orbital insertion. Then' I screwed it up because I had placed the ship backwards by reading the Nav Ball wrong. Oh well, I will try again later tonight.

Edited by SRV Ron
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thanks for the advice, watching and reading hasn't helped me much, I know how to make my orbit higher and lower. I crashed into mun today, I just launched and added random manuvers until I was in its orbit then I lowered the lowest point of the orbit until it was on the surface and went for it. didn't really know how to slow down cause I ran out of fuel and the parachute on the stock kerbal x ship didn't help LOL i'm slowly learning

Js4wchV,vLVoflG#0

Js4wchV,vLVoflG#1

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Parachutes won't help with the Mun or Minimus - no atmosphere to catch.

Making it to the Mun with a stock ship is a good thing. :) And yes, landing is a PAIN. You can try landing on Kerbin (suborbital, don't need to go into orbit for this). If it loks like it's going REALLY badly, pop the chutes, and try again.

Things to remember about landing - kill your LATERAL velocity, you want to land moving straight up and down (well, down)...

...the altimeter on the nav ball is NOT RIGHT. The one in the cockpit gives height above ground. The nav ball is height above SEA LEVEL. (or Mean Surface Level, for the whole body) So check that once, FAST, when you've picked out a landing spot.

The final touchdown needs to be SLOW. You may want different kinds of engines on the lander, and action groups to activate them, for finer control of landing.

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Parachutes won't help with the Mun or Minimus - no atmosphere to catch.

Making it to the Mun with a stock ship is a good thing. :) And yes, landing is a PAIN. You can try landing on Kerbin (suborbital, don't need to go into orbit for this). If it loks like it's going REALLY badly, pop the chutes, and try again.

Things to remember about landing - kill your LATERAL velocity, you want to land moving straight up and down (well, down)...

...the altimeter on the nav ball is NOT RIGHT. The one in the cockpit gives height above ground. The nav ball is height above SEA LEVEL. (or Mean Surface Level, for the whole body) So check that once, FAST, when you've picked out a landing spot.

The final touchdown needs to be SLOW. You may want different kinds of engines on the lander, and action groups to activate them, for finer control of landing.

now I have to figure out how I got in its orbit.. I keep overshooting

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Landing definitely is a pain :).

Do you understand the markings on your navball, yet? For landing, the big one you want to pay attention to is called your 'retrograde' marker - it's a green circle with an X through it. What it means is - that's exactly the opposite of the direction you're moving. Pointing towards retrograde and burning slows you down - so that's obviously what you want to do when you're landing, right?

The most efficient and most dangerous way to land is often called a suicide burn. That's timing it so you point retrograde, throttle up to MAX, and hit zero speed just as your spacecraft bumps into the ground. Obviously, if you misjudge the timing you're going to crash.. so you do have to take it more cautiously, but the more time you spend burning the more fuel you waste, so there's that trade-off. Try holding off slowing down till about 7, 8 kilometers up - and then slow-burning to keep speed reasonable till you see your shadow. Of course it depends how fast your ship can decelerate - if your ship's slow, you gotta do it earlier.

As you slow down, your retrograde marker'll naturally start to point more towards the center of the blue area on your navball - that's right straight up, cuz you'll be killing your horizontal velocity and the moon'll be pulling you straight down. You definitely want your retrograde marker to be as close to straight up as possible before you hit the ground. You'll find you can sorta 'push' it around by burning on the side of it.

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To plan a landing, I use the maneuver nodes. One to plot a course to the spot I'm aiming for, and one, with the node right above the surface, is the deceleration burn. The closer, the better. I pull on the retrograde handle until the trajectory is a straight line, showing I've killed almost all my velocity.

Sometimes I use a few more nodes.

eajix4b.png

I do that burn more or less as soon as the "time until node" number matches the "burn time" number. This gives me roughly the time when I need to start the burn so I'm not doing it too late, or wasting fuel by slowing too much, too early.

After that burn, aim at the retrograde marker to slow down. Be careful not to oversteer. A landing at 10m/s is fine for most craft.

As for not tipping over, make your lander wide. Wait till you're more practiced before you try and land tall things.

Landing is a great skill to master. It's not the easiest thing.

Also, Welcome to the forums!

Edited by Tw1
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Landing definitely is a pain :).

Do you understand the markings on your navball, yet? For landing, the big one you want to pay attention to is called your 'retrograde' marker - it's a green circle with an X through it. What it means is - that's exactly the opposite of the direction you're moving. Pointing towards retrograde and burning slows you down - so that's obviously what you want to do when you're landing, right?

The most efficient and most dangerous way to land is often called a suicide burn. That's timing it so you point retrograde, throttle up to MAX, and hit zero speed just as your spacecraft bumps into the ground. Obviously, if you misjudge the timing you're going to crash.. so you do have to take it more cautiously, but the more time you spend burning the more fuel you waste, so there's that trade-off. Try holding off slowing down till about 7, 8 kilometers up - and then slow-burning to keep speed reasonable till you see your shadow. Of course it depends how fast your ship can decelerate - if your ship's slow, you gotta do it earlier.

As you slow down, your retrograde marker'll naturally start to point more towards the center of the blue area on your navball - that's right straight up, cuz you'll be killing your horizontal velocity and the moon'll be pulling you straight down. You definitely want your retrograde marker to be as close to straight up as possible before you hit the ground. You'll find you can sorta 'push' it around by burning on the side of it.

this is a big help I never noticed that marker, thank you

the maneuver node method is a little complicated i'll have to try that when I have my ship perfected

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this is a big help I never noticed that marker, thank you

the maneuver node method is a little complicated i'll have to try that when I have my ship perfected

It will save you tons of fuel as you use its handles to search for the most efficient maneuvers. Most useful for reaching targets that do not lie on your orbital plane. Do plan on doing correction burns later to fine tune your course. They should be quite short lasting only a few seconds. And, as I found out last night, split the burn time. If your burn time is 20 seconds, start the burn at ten seconds to go.

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