0.90 Satellite Mission "Specific Orbit" Tolerance?

[CanOfUbik]

Hi All,

I'm new to the forum and new to the game also (started about two weeks ago). So, Beta crashed right into my learning phase. So far, I like it, but now I got a mission which seemingly can't finish:

The mission ist to "Position satellite in specific orbit of the Mun". I've got two of the three criteria checked: launching a new probe and maintaining stability for ten seconds.

What doesn't check is: "Reach the designated orbit around the Mun with minimal deviation".

I've done everything to come as close to the orbit as possible: Apoapsis is 1,509,130m vs 1,509,845m target. Periapsis is 1,417,300m vs. 1,417,845 target. Inclination is as far matched as possible, if there's any deviation left, it's not visible on the map. Periapsis and Apoapsis are with in 3 Minutes of target, while the whole orbit takes 2d, 2h, 40m. Thats about 0.35% deviation.

With that large an orbit I can't get any closer, even the shortest, slightest burn makes apoapsis or periapsis jump by about 1km.

So, all in all I'm lost. The only explanation I can come up with is, that the orbit tolerance of the mission must be defined in absolute and not in relative terms, so it becomes unplayable with large numbers.

Any other ideas? Am I missing something?

Edited December 20, 2014 by CanOfUbik

[Vectura]

If I remember right you have to be within something like 5m. Not sure though, don't trust what I say

[bandi94]

Make sure that your orbit direction is right. It's most possible you orbit in the other direction than the given orbit direction. Check the moving dots on the orbit and make sure you move along them and not against them

[DeepOdyssey]

Bandi94 is right. I've made a similar mistake of going in other direction, was really confused, because my orbit was perfect, yet the game didn't accept it. So i relaunched i opposite direction, this time it was fine.

[Rusty6899]

I have found that you don't need to be that close with the orbit. I think on one of mine I cut my engine about 5% short of the target Ap, it still gave me credit for completing the mission. I think it's probably the direction.

[Frostiken]

I go into the persistence files and edit the deviation tolerances myself. Some of them are WAAAAAAY to strict for the crazy orbits they want you to achieve.

I find it odd that they want you to have such exact orbits, but Harvester himself has basically been against adding any kind of actual numeric feedback to the game regarding your orbital parameters. It doesn't feel right whatsoever to have the game tell me "Inclined at 63.2 degrees" but I'm supposed to just eyeball it? Why the hell would you give me a goal accurate down to a tenth of a degree, and expect me to EYEBALL IT?

[Red Iron Crown]

Make sure that your orbit direction is right. It's most possible you orbit in the other direction than the given orbit direction. Check the moving dots on the orbit and make sure you move along them and not against them

I would give long odds that this is the problem. Hover your mouse over the ascending node, if it reads 180 degrees the satellite is orbiting backwards.

[Ziff]

I would give long odds that this is the problem. Hover your mouse over the ascending node, if it reads 180 degrees the satellite is orbiting backwards.

Or click on the [+] Notes section in the Contract and it will tell you the Inclination. 0-90 is a prograde orbit, 90-180 would be a retrograde orbit. (Not directed at you Red Iron Crown, just adding to what you said.)

[Kryxal]

Eyeballing inclination does seem pretty silly ... you'd NEED a mod to catch that without feedback. I was thinking of matching against a known craft in an equatorial orbit, but where do you find out for THAT one?

[Red Iron Crown]

Eyeballing inclination does seem pretty silly ... you'd NEED a mod to catch that without feedback. I was thinking of matching against a known craft in an equatorial orbit, but where do you find out for THAT one?

Target the Mun from the reference vessel.

[Kryxal]

Yes, but are there missions for orbits around, say, Minimus?

[Kobymaru]

TBH, I think those satellite placing contracts are really easy, because the deviations can be "huge". Maybe not in %, but in absolute values they can be off by dozens of kilometers. It's a bit harder without SAS, but I placed satelites much, much more precise than that in .25.

To OP: I had the same contract. It's the one that intersects the Mun Orbit, right? Yeah, that is a retrograde orbit. Check Ascending/Descending node markers to confirm.

I go into the persistence files and edit the deviation tolerances myself. Some of them are WAAAAAAY to strict for the crazy orbits they want you to achieve.

I find it odd that they want you to have such exact orbits, but Harvester himself has basically been against adding any kind of actual numeric feedback to the game regarding your orbital parameters. It doesn't feel right whatsoever to have the game tell me "Inclined at 63.2 degrees" but I'm supposed to just eyeball it? Why the hell would you give me a goal accurate down to a tenth of a degree, and expect me to EYEBALL IT?

No. There are Ascending/Descending node markers on the target orbit. Just wait until you fly up to those, then change the inclination to match the plane.

[cicatrix]

As a former non-stock Fine Print user I can say that tolerances were indicated in the mission assignment and were usually 5-7%. Since 0.90 came out I've placed already over a dozen or so satellites (the easiest and quickest way to make money/science - you can take several similar contracts at the same time and place your only satellite on all of them).

I messed with my maneuver node once and 'missed' the target orbit by several hundred kilometers. Just as I was trying to correct it I saw 'mission accomplished'. There must be something obviously wrong with your orbit (or not all conditions were met) because you can literally eyeball your target orbit and get away with it - check if your sat is going in the indicated direction and you have the same approximate inclination.

[CanOfUbik]

D'oh.

Thanks guys!

Heading was the problem... going full speed ahead in the wrong direction. Luckily I put quite a lot of surplus fuel on that probe, enough to flip the orbit. After that it was rather easy to finish.

[Geschosskopf]

Or click on the [+] Notes section in the Contract and it will tell you the Inclination. 0-90 is a prograde orbit, 90-180 would be a retrograde orbit. (Not directed at you Red Iron Crown, just adding to what you said.)

There's an easier way. If you look close at the target orbit shown on the map, you'll notice there are little dots of light all around it and these dots are moving around the orbit in the direction you need to be going.

Eyeballing inclination does seem pretty silly ... you'd NEED a mod to catch that without feedback. I was thinking of matching against a known craft in an equatorial orbit, but where do you find out for THAT one?

It's actually quite easy to eyeball inclination. Your AN and DN relative to the target orbit are where your orbit crosses the plane of the target orbit. So rotate the view in 1 direction until the target orbit shows up as a line instead of an ellipse. Then rotate the view at an angle along the same line as the target orbit, so the target orbit remains displayed as a line while you turn your existing orbit into a line as well. When you get there, the AN and DN are lined up directly in the center of the screen, where the lines of the 2 orbits intersect. Create a node there and burn as needed to make the 2 lines be drawn atop each other.

NOTE: It's generally a good idea to get your Pe and Ap lined up with the target Pe and Ap, and at about the correct distance, before doing the inclination burn. Makes it easier to line up the view and is usually cheaper on fuel, too. And, of course, make sure you check which way the dots of light are moving before you launch .

But as to the tolerance of how close you have to get, it appears to look for some total amount of error in all parameters instead of requiring each parameter to be within some tolerance individually. Many times I've gotten my Ap and Pe pretty much dead on but have had the contract complete while the inclination was still significantly off.

[Ziff]

There's an easier way. If you look close at the target orbit shown on the map, you'll notice there are little dots of light all around it and these dots are moving around the orbit in the direction you need to be going.

Yes, but everyone is apparently missing those little dots of light which is how the end up here wondering why they can't complete the contract. Figured I would throw another way to tell other than the dots flashing around. Besides, that works great for low inclination orbits but it can be hard to tell with Molniya orbits which way is which.

[The Yellow Dart]

I'm supposed to just eyeball it? Why the hell would you give me a goal accurate down to a tenth of a degree, and expect me to EYEBALL IT?

If you look at the target orbit, it gives you not only the apoapsis and periapsis, but also the ascending and descending nodes on the target orbit. I used these to launch at the right time and get my initial orbits inclination difference down to under 1°. To do this, focus your camera on kerbin and line up the asc. and desc. nodes so that they look like this on the screen over the equator: ><, then timewarp until your ready to launch craft is between the arrows: >x<, and gravity turn in the proper direction. Then I get it down to 0° once the orbit is close in size to the target just by burning normal or anti-normal when near the nodes.

Target the Mun from the reference vessel.

This doesn't work until you upgrade your tracking station so it might not help the OP.

[Red Iron Crown]

This doesn't work until you upgrade your tracking station so it might not help the OP.

Good point. You can also watch the navball closely for an orbit, a 0-inclination orbit will always point directly east.

[tigger]

Still doesn't work for me. My AP is 2300730m vs. desired 2299663m (0.04% difference), PE is 12083451 vs. desired 12081700 (0.01% difference). AN/DN say 0%, satellite orbits in the direction of the dots, but reaching orbit does not complete.

[Srpadget]

Lots of folk have been having trouble understanding these missions. Some are having trouble with the very precise values provided for orbital parameters in the mission description, others are getting tripped up with the simple existence of all those numerical orbital parameters which they have never seen anywhere in the game and which one cannot obtain values for in stock; but most seem to have troubles with the direction of the orbit.

Seems to me that in a future update, the mission description needs to include the phrase "match the orbit track found in Map View" (along with the numerical data, which actually is useful to some of us even in stock), and the directional "tracking lights" moving along the orbit should be made brighter/higher-contrast. That would appear to solve everyone's problems.