Laythe: Optimal ascent path.

[Motokid600]

My lander is ready to take off from the surface of Laythe to meet up with the CM. So id like to learn an ideal ascent path that fits Laythe's thin atmosphere. Now the lander uses four of the B9 turbo jets and alot of the large intakes. The jets will go until flame out where they will decouple and rockets fire to complete orbit. So what would be a nice trajectory for such a craft? I'll post a pic later when I can if needed.

Couldn't find anything with a search.

Edited August 23, 2013 by Motokid600

[lumpman2]

I did do some research and I found that at

0m the terminal velocity is ~100m/s

100m is ~101m/s

1km is ~113m/s

10km is ~342m/s

So you should probably try to stay near the closest terminal velocity to you. Also keep in mind that jet engines will power up slowly, so start out slow throttle up a little before you reach those altitudes. The jets will flame out at about 19km (because I really just looked at a video on youtube of turbo jets flaming out and multiplied the general altitude by 0.8, which is the scale of Laythe's atmosphere to Kerbin's).

[Radiokopf]

with a plane just go up to 10km and look at the intakes/speed. The path varries with both of those...

[Traches]

I imagine you'd want to stay at the highest altitude that will get you full power from your jet engines, for as long as possible while you build up speed. Then when you switch to rockets pitch back up and get out of atmo.

[Motokid600]

Thanks lumpman that's some good info. This isn't a plane in anyway. Just a regular ascent stage with jets. So I'm guessing I should start the gravity turn around 5km. Id like to stay in atmosphere as long as possible, but there are no lifting surfaces. But the thing has a very good TwR so the power of the engines should be able to keep it up. Just can't tip over to much. I've only gotta get up to 60km so it should do it. Hell the thing reaches LKO with ease so Laythe would be a sinch. I was just curious about how the jets will perform on Laythe versus Kerbin.

[Motokid600]

I imagine you'd want to stay at the highest altitude that will get you full power from your jet engines, for as long as possible while you build up speed. Then when you switch to rockets pitch back up and get out of atmo.

Any idea what that sweet spot might be?

[Oggula]

My longrange planes have 16 intakes to each turbojet. For the Stock turbojets I initially level out at 18km and progress up to 21-22km height by which time my apoapsis is 600k. You shouldn't need rockets to escape Laythe's atmosphere if you use enough intakes

[Specialist290]

If it helps, a while back I created a comparative atmospheric density table for all planets that have atmosphere. If you know at about what altitude your jets flame out on Kerbin, you should be able to find the equivalent range of altitude for that pressure on Laythe fairly easily.

[numerobis]

Orbital speed is less than 1900 m/s, so you can probably break out of the atmosphere just off jets. With stock turbojets it's pretty easy to get apoapsis close to the SOI boundary.

[Zeroignite]

If it helps, a while back I created a comparative atmospheric density table for all planets that have atmosphere. If you know at about what altitude your jets flame out on Kerbin, you should be able to find the equivalent range of altitude for that pressure on Laythe fairly easily.

And for the visually inclined, I have this:

[Specialist290]

Oo, nice! I'll have to add that one to the Drawing Board

[Motokid600]

Cool thanks everyone. Worked like a charm.