Sub-orbital Launch issues

[plattnat]

Hey,

I've built a manned spaceplane that currently only goes sub-orbital, i've mounted a probe ship on top of it and once I hit the height peak of the plane, i separate the two and pilot the drone to orbit.

When i separate I can control both crafts for a short period but i have to eventually go with the orbit probe and insert it into orbit. This is where the problem lies, the spaceplane disappears and the kerbals flying it are dead...

What can i do to save them? The plane is aerodynamic enough that it should give me about 10 minutes or more before its too close to the ground to recover.

I know there are better ways to do this but I just like the idea of it, is this a known issue?

Edited November 17, 2015 by plattnat

[Pthigrivi]

I've played with this before, depending on your launch profile you should be able to switch to the probe, fire its engines to bring its apoapsis up to to where your parking orbit will be (or circularize if you have the time, but it sounds like you dont), then switch back to the plane, land it, then go back to the probe and tweak its orbit or send it to its destination.

[Motokid600]

It cant be done conveniently. Right now craft will disappear after 2.7km ( I think it's 25km in atmosphere, but... Once you leave with the other craft its gone ) The only way to do it I can see is a very powerful space plane that can shoot up to an apoapsis high enough above 70km to give you enough coast time to decouple its payload and then fly that seperate craft to orbit. Then before the plane falls too far back down ( I think you have until like 35km of altitude before it'll dissapear on the way back down ) switch to the plane, hope it's stable and then fly it back and land.

The problem is the plane needed is so radical your better just making a simple rocket stage that can be recovered in the same manner.

Edited November 14, 2015 by Motokid600

[Snark]

It's a basic feature of the game design. It makes missions such as you are trying to do not very practical.

Yes, there are ways to work around it, but they're awkward.

Here's the deal:

KSP runs a "physics bubble" around the currently-controlled ship. The radius of this bubble is 2.3 km when you're in vacuum, 20+ km when you're in atmosphere.

All ships that are outside the "physics bubble" run "on rails": that is, they have no physics simulation at all, they're just mathematically following their orbital trajectories. Ships that are inside the "physics bubble" are fully simulated, just as your own currently-controlled craft is.

Ships that are outside the "physics bubble" are, for the most part, "frozen" and unchanging: they live forever, they don't consume any resources, don't use battery power, etc. (One notable exception is that if you have a ship that's mining, it continues to mine while on rails.)

However: Ships on rails will die (be silently deleted from the game) if they crash into a planet. As far as the game is concerned, "crashing" means either intersecting terrain (in the case of vacuum worlds), or entering atmosphere that's greater pressure than 1% of Kerbin sea-level pressure.

On Kerbin, that pressure occurs at around 23 km of altitude.

What this means is that any ship will be silently deleted if it meets all of the following criteria simultaneously:

1. Is not currently being controlled by you
   
2. Is below 23 km altitude (on Kerbin)
   
3. Is more than 20 km away from your currently controlled ship.
   

It's still possible to launch a mission such as you're attempting, but you need to fudge it so that your lower stage never meets the above three criteria at once. For example,

1. fly to high-suborbital trajectory
   
2. separate when you're over 23 km and climbing fast
   
3. upper stage does a quick burn to fling it well above the atmosphere
   
4. immediately switch back to your lower stage (before it falls below 23km altitude)
   
5. land it as quickly as you can (before your upper stage reaches Ap)
   
6. switch back to your upper stage and do orbital insertion.
   

[Motokid600]

I really hope in 1.1+ those limitations are history. You should be able to prioritize with a simple checkbox which craft you want to keep loaded.

[Brainlord Mesomorph]

OPTION 2:

If you can get the plane into space it will continue "on rails" until reentry.

So you can get the whole package into space, separate the payload, have it make orbit, and get back to the plane before it hits the atmosphere, and pilot it in.

[plattnat]

[quote name='Snark']It's a basic feature of the game design. It makes missions such as you are trying to do not very practical.

Yes, there are ways to work around it, but they're awkward.

Here's the deal:

KSP runs a "physics bubble" around the currently-controlled ship. The radius of this bubble is 2.3 km when you're in vacuum, 20+ km when you're in atmosphere.

All ships that are outside the "physics bubble" run "on rails": that is, they have no physics simulation at all, they're just mathematically following their orbital trajectories. Ships that are inside the "physics bubble" are fully simulated, just as your own currently-controlled craft is.

Ships that are outside the "physics bubble" are, for the most part, "frozen" and unchanging: they live forever, they don't consume any resources, don't use battery power, etc. (One notable exception is that if you have a ship that's mining, it continues to mine while on rails.)

However: Ships on rails will die (be silently deleted from the game) if they crash into a planet. As far as the game is concerned, "crashing" means either intersecting terrain (in the case of vacuum worlds), or entering atmosphere that's greater pressure than 1% of Kerbin sea-level pressure.

On Kerbin, that pressure occurs at around 23 km of altitude.

What this means is that [B]any ship will be silently deleted if it meets all of the following criteria simultaneously:

[/B]
[LIST=1]
[*]Is not currently being controlled by you
[*]Is below 23 km altitude (on Kerbin)
[*]Is more than 20 km away from your currently controlled ship.
[/LIST]

It's still possible to launch a mission such as you're attempting, but you need to fudge it so that your lower stage never meets the above three criteria at once. For example,

[LIST=1]
[*]fly to high-suborbital trajectory
[*]separate when you're over 23 km and climbing fast
[*]upper stage does a quick burn to fling it well above the atmosphere
[*]immediately switch back to your lower stage (before it falls below 23km altitude)
[*]land it as quickly as you can (before your upper stage reaches Ap)
[*]switch back to your upper stage and do orbital insertion.
[/LIST]
[/QUOTE]

I think this what I was going for, I was just trying to see if its a more cost effective method. I was hoping I could enable an autopilot on the plane to level the plane out and keep it from destroying itself.