How to stay at the sunny side

[Dedjal]

Does anyone have the data on the altitude and speed required to always remain on the side of a planet where the sun always shine? Or could point me in a direction of a former post regarding this issue, formula or anything inbetween?

D

[allmappedout]

Unless I'm missing something obvious, the only place that you could do that would be if you were orbiting the planet at a distance of 1 AU....which would put you smack bang within the Sun....? Still, it would be guaranteed to be sunny!

[Pursuedtank]

Is that even possible, surely at one point in your orbit you are going to be behind the planet. Even in a polar orbit wouldn't the movement of the planet around the sun eventually mean that you went behind the planet?

[rryy]

What do you mean by this, an orbit where Kerbin doesn't pass in front of the sun or an altitude for flying a plane? For flying a plane, just fly west at roughly 170 m/s to keep up with the rotation of Kerbin, or just set the velocity to show orbital and keep it around 0. If you mean an orbit, a polar, extremely high orbit should be good because Kerbin would be so small that any time it blocks the sun, which should be rarely, will only be for a short time.

Edited May 19, 2013 by rryy

[Rhomphaia]

L1 would do it, unfortunately KSP doesn't support Lagrange points so you cant do this

[DerekL1963]

Is that even possible, surely at one point in your orbit you are going to be behind the planet. Even in a polar orbit wouldn't the movement of the planet around the sun eventually mean that you went behind the planet?

http://en.wikipedia.org/wiki/Sun-synchronous_orbit

Yes, it's possible.... you just have to orbit over the terminator. (Sunrise/sunset.) If you're launching from a planet, launch into a polar or near polar orbit at sunrise or sunset. If you're already in orbit, change planes to polar or near polar and precess your orbit. When you start to drift into shadow, just precess again. (Keep in mind that the higher your orbit, the less time you spend in shadow.)

[Fractal_UK]

Yes, you just need to put yourself in a polar orbit, then introduce a small equatorial velocity component to precess your orbit and keep you over the day-night terminator all year. These orbits have been used for solar observation satellites and such.

Edited May 19, 2013 by Fractal_UK

[Psycho0124]

..or just set the velocity to show orbital and keep it around 0...

You can manually switch between orbital/surface velocity on the gimbal? That would be so useful! How?

[Fractal_UK]

You can manually switch between orbital/surface velocity on the gimbal? That would be so useful! How?

Just left click on the velocity indicator to switch between surface, orbital and target velocity.

[Cooly568]

You would have to orbit at a location that's speed equaled the planets rotation speed.

[iamaphazael]

You can manually switch between orbital/surface velocity on the gimbal? That would be so useful! How?

Just click on the velocity readout and it should cycle through Surface, Orbital, and Target (if you have one set) modes.

[Psycho0124]

Thanks! That's going to make landing on kethane deposits so much easier! Waiting until low altitude for it to automatically switch to surface setting is such a pain (if it even switches at all; I've had to eye-ball high altitude landings on Minimus with my gimbal set to orbital velocity so many times.)

[SecondGuessing]

http://en.wikipedia.org/wiki/Sun-synchronous_orbit

Yes, it's possible.... you just have to orbit over the terminator. (Sunrise/sunset.) If you're launching from a planet, launch into a polar or near polar orbit at sunrise or sunset. If you're already in orbit, change planes to polar or near polar and precess your orbit. When you start to drift into shadow, just precess again. (Keep in mind that the higher your orbit, the less time you spend in shadow.)

A sun-synchronous orbit doesn't meant you're always in the sun, it means that the illumination over an arbitrary point will be the same every time you pass over that point.

L1 would work, but KSP doesn't support Lagrange points. I don't see much of a way to do it with KSP's physics. If you put yourself in a high polar orbit around the terminator, though, you'll be in the sun for a long time before you finally get eclipsed, and even then it'll only be for a very short while. A little nudge towards the terminator every now and then would mean you always stay in the sun. There might be a distance at which you can be in a retrograde orbit that matches the rotational velocity of Kerbin, too.

[Holo]

If you orbit at a high altitude, won't Kerbin only transit the sun, not block it?

[Fractal_UK]

A sun-synchronous orbit doesn't meant you're always in the sun, it means that the illumination over an arbitrary point will be the same every time you pass over that point.

L1 would work, but KSP doesn't support Lagrange points. I don't see much of a way to do it with KSP's physics. If you put yourself in a high polar orbit around the terminator, though, you'll be in the sun for a long time before you finally get eclipsed, and even then it'll only be for a very short while. A little nudge towards the terminator every now and then would mean you always stay in the sun. There might be a distance at which you can be in a retrograde orbit that matches the rotational velocity of Kerbin, too.

Actually the orbit that Derek is talking about is a special case of a sun synchronous orbit whereby the spacecraft always orbits over the equator when it is in sunlight at all times of the year . This orbit is a synchronous polar orbit with a small horizontal component that precesses the orbit around the planet at the same rate as the planets rotation around the sun, thus the craft remains in sunlight at all times.

Edited May 19, 2013 by Fractal_UK

[Dedjal]

So this is a bit harder than I though.

No wonder all my tries has ended in failure.

Why is it so hard to make a object gaze down at the beautiful Kerbin nature, always bathed in light?

Geosynch is possible, why not "sunsynch"?

[Itsdavyjones]

if you want to stay on the ground, make a rover or plane that goes as fast as the sidereal rotation of the planet/moon in the opposite direction of rotation, as for sun sync, needs langrain point, which isn't in the game.

[Fractal_UK]

if you want to stay on the ground, make a rover or plane that goes as fast as the sidereal rotation of the planet/moon in the opposite direction of rotation, as for sun sync, needs langrain point, which isn't in the game.

You do not need Lagrange points to do this. You simply put your orbit over the equator at dawn, half a day later you pass the equator at dusk. Noon and midnight are passed at the poles where the planet does not block any light from the sun. A small inclination with respect to the poles keeps you in this orbit all year. I believe this inclination is around 0.85 degrees for Kerbin, assuming that I've interpreted its orbital properties with respect to real time correctly.

[Dedjal]

Well, I wanted a spacestation in orbit around Kerbin, positioned so that it was always in the sun.

I figured out how to do it in the end, but it kinda ruins my expectations and plans, so it's scrapped for now.

For those who's curious, here's how to always hover above a planet while "always" remaining in the sun:

Escape the planets (and the moon(s) gravity). Place yourself between the aforementioned planet and the sun, speed up until you go a bit faster than the planet (posting on cellphone, so formula etc won't be digged up now. But think of a grammofon disc. Inner layer goes faster round than the one on the outside, yet they complete a turn on the same time). Tada, always in the sun spot, too far away to be any useful for what I wanted to do

[Fractal_UK]

Well, I wanted a spacestation in orbit around Kerbin, positioned so that it was always in the sun.

I figured out how to do it in the end, but it kinda ruins my expectations and plans, so it's scrapped for now.

For those who's curious, here's how to always hover above a planet while "always" remaining in the sun:

Escape the planets (and the moon(s) gravity). Place yourself between the aforementioned planet and the sun, speed up until you go a bit faster than the planet (posting on cellphone, so formula etc won't be digged up now. But think of a grammofon disc. Inner layer goes faster round than the one on the outside, yet they complete a turn on the same time). Tada, always in the sun spot, too far away to be any useful for what I wanted to do

It does not work that way, if you put yourself in a lower orbit around the sun, your orbital period would not match the planet's. Think about it, if it did, the planets would remain at a fixed position relative to one another at all times since they'd all have the same rotation period. Orbits around a particular body do not have fixed angular frequency.

Edited May 19, 2013 by Fractal_UK

[Specialist290]

It does not work that way, if you put yourself in a lower orbit around the sun, your orbital period would not match the planet's. Think about it, if it did, the planets would remain at a fixed position relative to one another at all times since they'd all have the same rotation period. Orbits around a particular body do not have fixed angular frequency.

This. Orbits do not work the same way as records do. Your station's orbit is eventually going to get out of sync with the planet. It'll take more or less time to happen depending on the distance between their orbits, but it will happen just the same.

On the plus side, the station will stay in the sunlight.

[Dedjal]

Ah, well. I only let my station run alongside Kerbal for a little while, so I had no chance to observe what would happen after doing some circuts around the sun. I only assume that it would function the same way as a grammofone.

Thank you all. Derek's suggestion sounds interesting, must try it out, right after I am done building this pure SRB Duna rocket.

Aspargus, with SRB's

[hyperformer]

scott manley did a video where he did a circumnaviagtion in a solar plane so heres the link

[tomf]

You can't have a sun-synchronous orbit in KSP. In real life they depend upon the precession caused by the oblateness of Earth.

You could set up an orbit that follows the terminator now, but in 1/4 of a Kerbin year it will be aligned to orbit over noon/midnight.

[Fractal_UK]

You can't have a sun-synchronous orbit in KSP. In real life they depend upon the precession caused by the oblateness of Earth.

You could set up an orbit that follows the terminator now, but in 1/4 of a Kerbin year it will be aligned to orbit over noon/midnight.

No, the oblateness of the Earth is just an extra factor to correct for which accentuates the the inclination required for the orbit. It is possible to do in KSP but it requires a very tiny inclination from the plane of the terminator, making it rather hard to set up.