displaced geostationary orbit?

[kalor]

Is this possible? What I am looking for isn't even really the geo-stationary orbit so much as orbiting on the "horizontal", IE the same direction (or opposite) that Kerbin is travelling, but I want to do it further in the "vertical", or, in this case, closer to one of the poles.

In the case of earth, this would be equated to travelling the same direction as a GSO, but doing so over Canada, rather than the equator. (And yes, I do realize that it isnt possible at this point to be stationary, I'm more concerned with the change of plane)

Any thoughts, or advice on how to do it properly? I've tried with MJ, but I just end up with an inclined orbit, rather than parallel to the equator.

Edited August 26, 2014 by kalor

[Stargate525]

Is this possible? What I am looking for isn't even really the geo-stationary orbit so much as orbiting on the "horizontal", IE the same direction (or opposite) that Kerbin is travelling, but I want to do it further in the "vertical", or, in this case, closer to one of the poles.

In the case of earth, this would be equated to travelling the same direction as a GSO, but doing so over Canada, rather than the equator. (And yes, I do realize that it isnt possible at this point to be stationary, I'm more concerned with the change of plane)

Any thoughts, or advice on how to do it properly? I've tried with MJ, but I just end up with an inclined orbit, rather than parallel to the equator.

You can't get an orbit parallel to the equator. An orbit has to cross the equator. You can incline it, eccentricize it, but it will always cut across the orbiting body's center of mass.

You could do it in theory, but you would have to be constantly burning to keep your orbit up there.

Edited August 26, 2014 by Stargate525

[MockKnizzle]

The inclination of an unpowered orbit can be no less than the highest latitude you want to orbit over. If you want to orbit over, say, British Columbia at a latitude of 50 degrees, your orbit must be inclined at least 50 degrees. A consequence of this is that you also cannot launch directly into an orbit with an inclination less than the latitude of the launch site (a Soyuz from Baikonur cannot launch directly into an equatorial orbit, for instance).

It is possible to have a spacecraft move as you've described, but it must be constantly thrusting northwards.

[kalor]

Ah... I was reading a short article about displaced orbits, but I missed a detail they mentioned... using hybrid solar sails to maintain the orbit... sad :<

An interesting article, nonetheless, if anyone cares to take a quick read. Pretty short.

http://www.sciencedaily.com/releases/2010/07/100726094749.htm

[Sirine]

Is this possible. With debug On constantly thrusting northwards, and constant 'active' of that particular craft. Once the craft lost 'focus', it lost it thrust, and lost its displaced orbit.

[kalor]

Kerbal physics interfering with nifty ideas *shakefist*

Oh well. T'was a thought

Edit: Interesting though that it lost the displaced orbit once it lost focus... I most not understand the "on-rails" phsyics I've been reading about somewhat properly? I figured it would maintain the orbit it was placed in, barring any encounters.

Edited August 26, 2014 by kalor

[MockKnizzle]

It's not about KSP physics, it's about real-life physics which KSP simulates.

The force of gravity is a vector which points directly towards the center of a planet. A spacecrafts's velocity is also a vector, aka prograde on the navball. While in freefall, these two vectors define a two-dimensional surface which is the plane of the orbit. Since one vector points directly at the center of the planet, the plane of the orbit must also intersect the center of the planet, and consequently must cross the equator.

[Kasuha]

You can use three probes on inclined Molniya orbits to have at least one satellite above the area at any time.

Edited August 26, 2014 by Kasuha

[AlexinTokyo]

Edit: Interesting though that it lost the displaced orbit once it lost focus... I most not understand the "on-rails" phsyics I've been reading about somewhat properly? I figured it would maintain the orbit it was placed in, barring any encounters.

Placing an object 'on rails' in KSP disables physics simulation for that object, preventing any forces acting on it. Since the displaced orbit requires a continual force, it cannot survive being put on rails, and the object will revert to the Keplerian orbit based on its current altitude, latitude, and speed at the time the force is stopped.

[G2-]

Just to put out an interesting point. There are also displaced orbits that do not require input from the spacecraft itself such as Sun Synchronous orbits around Earth. However with the simplifed physics of KSP the subtle effects that can affect real satellites and cause interesting non-standard orbits are missed. KSP simply wasn't designed for such complex orbital dynamics as they had no idea the community would progress this far!

[cantab]

An inclined geosynchronous orbit will make a figure-8 over the primary's surface. If the orbit is circular the figure-8 will be symmetric, probably not very useful, but if the orbit is elliptical the figure-8 will be asymmetric and the satellite can be made to spend most of its time over the northern or southern bit. This is known as a tundra orbit. A few satellites in such an orbit would give continuous coverage to a chosen area, though IRL the ground stations may require motorised dishes since the satellites will appear to move.

A Molniya orbit is similar, but semi-synchronous, orbiting twice a day.

[kalor]

The KSP physics I was referring to wasn't really physics, i was tired and used the wrong word... meant the on-rails aspect.

And I see, reagarding the way the on-rails works. The way I had understood it was wrong, and that makes much more sense.

[Red Iron Crown]

An inclined geosynchronous orbit will make a figure-8 over the primary's surface. If the orbit is circular the figure-8 will be symmetric, probably not very useful, but if the orbit is elliptical the figure-8 will be asymmetric and the satellite can be made to spend most of its time over the northern or southern bit. This is known as a tundra orbit. A few satellites in such an orbit would give continuous coverage to a chosen area, though IRL the ground stations may require motorised dishes since the satellites will appear to move.

A Molniya orbit is similar, but semi-synchronous, orbiting twice a day.

Won't a circular inclined synchronous orbit trace a North/South line on the surface? I though eccentricity was needed for any East/West libration, and a combination of both inclination and eccentricity for the figure eight.

[MarvinKitFox]

In the case of earth, this would be equated to travelling the same direction as a GSO, but doing so over Canada, rather than the equator.

This is easy.

Just apply the same technique commonly used when lifting yourself by the ankles.

Try it.

Bend over, grab your ankles. You are strong enough to lift your own body weight, right?

Ok, now *hoist* until you have lifted yourself a couple of feet off the ground.

Take careful note of how you did this.

Apply the same technique to make a satellite orbit as you describe.

[Red Iron Crown]

Maybe make a really long satellite (thousands of kilometers) and put it in GSO, with one end of it over Canada and the other over the Pacific west of Chile. Voila!

What material to use to make the satellite and how to get it into orbit are left as an exercise for the reader.

[Mandelbrot]

Won't a circular inclined synchronous orbit trace a North/South line on the surface? I though eccentricity was needed for any East/West libration, and a combination of both inclination and eccentricity for the figure eight.

If your satellite is not right over the equator, you will get east/west libration because as the equator moves eastward, your satellite has to move both north and then south in the sky as you just move east at the same rate. I think the analemma will be closer to a line the less inclined you are, and then become more figure-8 with high inclinations, because it takes more time to go that far north and south, so the loops back and forth across the sky will be even bigger.

[Red Iron Crown]

If your satellite is not right over the equator, you will get east/west libration because as the equator moves eastward, your satellite has to move both north and then south in the sky as you just move east at the same rate. I think the analemma will be closer to a line the less inclined you are, and then become more figure-8 with high inclinations, because it takes more time to go that far north and south, so the loops back and forth across the sky will be even bigger.

*Lightbulb* I get it now, thanks for that.

[Mandelbrot]

NP I've been thinking about this a lot recently due to Remote Tech.