Build an MK3 Spaceplane after 0.90 update

[Fire-Dragon-DoL]

Like I said, turbojets are more fuel efficient *in the atmosphere* that means you can reach orbit with more fuel! RAPIERs are nice on small planes because it means you don't need 2 kinds of engines. When you have loads of them that benefit disappears, so it's better to use turbojets (which will make it easier to get off the ground! more thrust!) for atmospheric flight and dedicated rockets for when you're ready to go to orbit. You can also get out of the atmosphere using only the turbos.

Thanks, it also appear turbojets give me that twr I was missing to actually take off.

Added a few tweaks (expecially some air intakes), and now it's time for a test flight, let's see if I can get to orbit.

[Fire-Dragon-DoL]

New problem... Rapier overheats instantly even at 32000m, they explode badly, and yes I'm screwed at that point

EDIT: Solved that, moved the rapiers far from eachother.

Fun, I used like 4000 fuel to get into orbit, I have like 1600 fuel remaining, completely inefficient.

I may try flying it in a more efficient fashion.

Edited December 21, 2014 by Fire-Dragon-DoL

[Fire-Dragon-DoL]

If you're running stock, you'd want to have the sum of the lift coefficients of your wing sections to equal the aircraft mass in tonnes. That gives a good balance between lift and drag.

example: a 75 tonne spaceplane would need the lift coefficients of it's wing panels to total 75. You'll still be okay if you're over this; it doesn't have to be exact.

The large wing connecters and delta sections have a lift coefficient of "2" per panel, so you'd want at least 38 of these panels total, or 19 panels per wing.

Check out my basic spaceplane tutorial from 0.25 here:

http://forum.kerbalspaceprogram.com/threads/102182-So-you-want-to-build-a-space-plane

If you're running FAR, I have no idea.

Good luck!

-Slashy

This is embarassing, I didn't notice the second page at all (actually I didn't notice I was on the 3rd page), so I missed this FANTASTIC suggestion.

Thanks a lot!

The previous one in any case didn't manage to make an efficient travel to orbit, so currently I'm working on a new big guy which should bring a full orange tank in orbit, let's see how much it takes.

[Anquietas314]

New problem... Rapier overheats instantly even at 32000m, they explode badly, and yes I'm screwed at that point

EDIT: Solved that, moved the rapiers far from eachother.

Fun, I used like 4000 fuel to get into orbit, I have like 1600 fuel remaining, completely inefficient.

I may try flying it in a more efficient fashion.

Heh, yeah don't place engines too close together - the attachment nodes on parts that connect one part to several others (e.g. 1->4 adaptors) are usually spaced far enough apart to prevent engines overheating (this may not apply to mod parts mind!)

[Fire-Dragon-DoL]

Heh, yeah don't place engines too close together - the attachment nodes on parts that connect one part to several others (e.g. 1->4 adaptors) are usually spaced far enough apart to prevent engines overheating (this may not apply to mod parts mind!)

I was on an adaptor, but I read around for rapier was not enough (definitely not considering the explosion )

[Fire-Dragon-DoL]

After creating this horror, named "Wingsandwich", I decided NOT to bring an orange tank in space, I'll try with half of it.

[Anquietas314]

I don't think you need that many engines dude... a lot certainly, but... 26? 28? Good lord. You should probably have a higher intake/engine ratio too. intakes matter much more higher in the atmosphere. My spaceplane had a total of 112 intakes for those 16 turbojets - 1 shock nose cone intake and 6 of the structural ones each. That wasn't enough for maximum efficiency.

[Norpo]

After creating this horror, named "Wingsandwich", I decided NOT to bring an orange tank in space, I'll try with half of it.

https://dl.dropboxusercontent.com/u/762638/Files/Images/Screenshots/mesorotshots/2014-12-21_17-09-16.jpg

Wow.

I'm just looking at that giant stack of structural wings. I can tell you're not using FAR.

[Anquietas314]

Wow.

I'm just looking at that giant stack of structural wings. I can tell you're not using FAR.

Hmm... would FAR be smart enough to notice you're stacking wings like that? It seems like that would be quite a tricky case to handle.

[Rakaydos]

Hmm... would FAR be smart enough to notice you're stacking wings like that? It seems like that would be quite a tricky case to handle.

You may have noticed whenever I post one of my double hull designs, someone comes out to say "Biplanes suck", because it IS a FAR design.

The skin drag of the most recent update is a pain in the butt, though. I have to lite my rockets way earlier than I want- though I can still make orbit, I'm not an efficent fuel transporter anymore, and a certintly cant single stage to minmus orbit of raipers anymore.

[Anquietas314]

You may have noticed whenever I post one of my double hull designs, someone comes out to say "Biplanes suck", because it IS a FAR design.

The skin drag of the most recent update is a pain in the butt, though. I have to lite my rockets way earlier than I want- though I can still make orbit, I'm not an efficent fuel transporter anymore, and a certintly cant single stage to minmus orbit of raipers anymore.

I hadn't noticed that seeing as this is the first thread I've seen you do it (I think) but biplanes are a little different from this case - there's a gap between the wings on a biplane, there isn't here.

[Fire-Dragon-DoL]

I don't think you need that many engines dude... a lot certainly, but... 26? 28? Good lord. You should probably have a higher intake/engine ratio too. intakes matter much more higher in the atmosphere. My spaceplane had a total of 112 intakes for those 16 turbojets - 1 shock nose cone intake and 6 of the structural ones each. That wasn't enough for maximum efficiency.

Whatever I make it comes out as an ugly thing, refuelers must be really big to bring in orbit fuel tanks

Any chance you know how much twr is required? I've read around 4 twr for a plane (which seems too much for me O.o), I wished 2 twr was enough + lift equal (or more) mass of the spacecraft.

[Anquietas314]

Any chance you know how much twr is required? I've read around 4 twr for a plane (which seems too much for me O.o), I wished 2 twr was enough + lift equal (or more) mass of the spacecraft.

In stock 2-3 seems to be enough for a small plane, but you probably do need 4 for a large one. I don't know about FAR seeing as I haven't used that mod.

[Fire-Dragon-DoL]

In stock 2-3 seems to be enough for a small plane, but you probably do need 4 for a large one. I don't know about FAR seeing as I haven't used that mod.

I'm doing some tests.

Following the suggestion (very good one), seems like lift = weight, you can take off with barely 1.11 twr (I'm doing that right now, keeping rapiers turned off). Also thinking about KSP, there is a high chance that lift = weight is what dev were aiming for, to make a valid spaceplane with twr ~1 (maybe 1.01).

It's interesting, I can replace rapiers with much more space-efficient engines, I only need the thrust to get out of atmosphere.

Not sure if however I'll consume more fuel with such low twr.

As usual, ugly as hell, but this guy reached orbit and came back, with half orange tank and some monopropellent.

EDIT:

I suggest 2 twr if you don't want get old

Edited December 21, 2014 by Fire-Dragon-DoL

[Anquietas314]

Fire-Dragon-Dol: btw, you know alt+print screen is a thing right? It takes a screenshot of only the active window. Also, I know I said you needed more intakes... but holy **** dude. you don't need THAT many! Especially not for just 4 turbojets! lol

[Fire-Dragon-DoL]

Ok, this time I made an optimized flight and wasn't bed.

I ended up with only 500 delta V, really low, but the tank is full and with monopropellent to spare!

[Wanderfound]

Craft file at http://forum.kerbalspaceprogram.com/threads/90747-Kerbodyne-SSTO-Division-Omnibus-Thread?p=1610271&viewfull=1#post1610271

[Anquietas314]

Nicely done. You should remove that excess oxidizer from the tank though, it's a lot of unnecessary mass

Edited December 21, 2014 by armagheddonsgw

[Fire-Dragon-DoL]

Fire-Dragon-Dol: btw, you know alt+print screen is a thing right? It takes a screenshot of only the active window. Also, I know I said you needed more intakes... but holy **** dude. you don't need THAT many! Especially not for just 4 turbojets! lol

Yes I know the alt+print thing, but I'm using a tool that auto generate the screenshot in my dropbox directory and this stupid thing doesn't support single window screenshot, sigh.

EDIT: My fault, found an option that allows me to use window screenshot too

Edited December 22, 2014 by Fire-Dragon-DoL

[Anquietas314]

Yes I know the alt+print thing, but I'm using a tool that auto generate the screenshot in my dropbox directory and this stupid thing doesn't support single window screenshot, sigh.

EDIT: My fault, found an option that allows me to use window screenshot too

Good to know you found that feature

[lirg03]

Does this count as an space plane? It takes off and lands vertically, but needs to accelerate around 20~25k before climb higher as a normal space plane.

[Fire-Dragon-DoL]

Does this count as an space plane? It takes off and lands vertically, but needs to accelerate around 20~25k before climb higher as a normal space plane.

http://i.imgur.com/GA0iQqG.png

http://i.imgur.com/XED9DVz.png

I'm not sure, can you land and take off with that again? Maybe with a parachute chain or something like that?

SSTO means single stage to orbit, so I think it's a yes in any case.

Anyway, I couldn't make a good looking ssto that at same time was as efficient as the following one. Also, I removed the cockpit, actually defeating my initial challenge of using MK3 parts, that cockpit is too big for a refueler. I definitely want new engines for SSTOs.

[Fire-Dragon-DoL]

http://i1378.photobucket.com/albums/ah120/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/Constellation/screenshot58_zpsa30efb21.jpg

http://i1378.photobucket.com/albums/ah120/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/Constellation/screenshot69_zps1ccdd5be.jpg

Craft file at http://forum.kerbalspaceprogram.com/threads/90747-Kerbodyne-SSTO-Division-Omnibus-Thread?p=1610271&viewfull=1#post1610271

This is fantastic and looks much better than mine. I'll check it later on today.

[Anquietas314]

Does this count as an space plane? It takes off and lands vertically, but needs to accelerate around 20~25k before climb higher as a normal space plane.

http://i.imgur.com/GA0iQqG.png

http://i.imgur.com/XED9DVz.png

I would have to say no, mainly because it does not have its main wings roughly on a (geometrical) plane with landing gear underneath (or on its back end if it's a tail-sitter). There might be a term for that kind of design though. The altitude it flies at isn't really important - 20-25km is quite common for a "normal" spaceplane.

[Wanderfound]

This is fantastic and looks much better than mine. I'll check it later on today.

Designed for FAR/DRE; it's unlikely to perform well in stock aero, unfortunately.