Jump to content

Help with spaceplance


Recommended Posts

Hi all,

First time poster, long time reader...

I've just started looking at space planes since the 1.0 release.

I've made the following space plane and with some work I've managed to build one that is stable, controllable (I spent a long time playing with the CoM & CoL) and will reach low space. But that's where it goes wrong. I just always seem to run out of oxidizer and can't achieve orbit let alone anything else...

Looking for tips really. I have searched but I've not really seen anything that helps as the areo model has been reworked.

Cheers.:)

2015-05-01_00005_zps29zxfy9c.jpg

2015-05-01_00002_zpsax4gyyjc.jpg

2015-05-01_00003_zpsg3kadj3p.jpg

2015-05-01_00004_zpsejmzvrv3.jpg

Link to comment
Share on other sites

Couple of things.

1. You're main wings have what is called anhedral. They are tilted downward. This places your center of lift below your center of mass and makes your plane want to fly upside down. Try dihedral (wings pointing up) instead.

2. The Intakes you're using (the silly rounded ones) are not designed for high speed and altitude. Also they are a source of unwanted drag. You should only need 1 good intake per engine and it should probably be the shock or ram intakes. A number of the smaller intakes that you have would also be fine.

3. Planes are even less forgiving then rockets with respect to drag. You NEED a good ascent profile. 1st get up to 10k. fly straightish until you get to 500m/s and pitch up between to around 15 degrees. Turn SAS on and let it fly. You're AoA will increase steadily as will your speed. You're aiming at around 850m/s at 25km. That is where you switch to rockets. Close your intakes and fly at about 10 degrees above your velocity marker (the yellow circle) until 35km and then just fly like a lawndart until your apoapse is 85km. It will fall until it reaches around 80km. wait until then and circularize.

4. If that doesn't work you wil likely need more fuel. I calculate you need 2500 m/s dv with rockets. I got that value from Kerbal Engineer Redux.

Link to comment
Share on other sites

Hi thanks for the reply.

I have since done a rework and I'm now using the ram intakes which is giving better results.

So far I've had no issues with stability but I see what your saying about the wings. I'll keep an eye on that.

I think the accent profile is my biggest issue...

Fuel is always my stopping issue but I think if I can work on that ascent path and the reworked airframe i might stand a better chance.

Thanks!

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...