1.2: Spaceplane in 30 parts with low tech

[WanderingKid]

So I've been poking around with 1.2 off and on between another project I've been working on, and I've decided to go bang my head on the wall to create a reusable spaceplane with as low a tech as I can get my hands on.  Preferably without upgrading anything (thus, 30 parts/18 tons) and max tech level 4 (the 45 cost tree region).

While doing this, and after banging my head on the wall repeatedly, I decided I'd poke my head in here and see if anyone had been taking up the idea... and haven't seen much.  I love Thrimm's work, but his lightest is a 25tonner.  I haven't seen much else out there.

So, has anyone been successful at this so far?  I assume someone (or many someones) have, so if you know of them, would you be kind enough to point me at them for some ideas?

[Vaporized Steel]

You can totally forget it.

You'll need a array of Junos just to get to a preferable altitude already taxing your part limit with Junos only. Then you can get all the LFO up to 18Tons weight limit and you will not have enough to get into orbit.
I tried this in 1.1.3 and I got a Juno/Reliant design up to 63km Apo with a burn out velocity of 1820m/s. So I would have needed quite a bit more to pull it off. I would see no way to get a additional 600+ m/s in that design not to mention spare LF for a powered landing.
You can do it with 45science nodes only. But not with a 18ton and 30 part limit.

What is your motive by the way? A spaceplane only career mode?

If that is the case then it is possible. But you will want to science/fund grind with Kerbin only missions. This is possible, and you can always get high orbit and space science data with suborbital flights.
You can get a R&D level 2 and unlock only the desired tech nodes and you may get panthers. On hard mode, it will be one hell of a grind. But it is possible.
 

Edited October 20, 2016 by Vaporized Steel

[KerikBalm]

Try just a pure rocket SSTO with some fins for re-entry and popping chutes over the runway? expect the payload capacity to be about zero...

You can't make a good airbreathing SSTO until you get the panther, which isn't so low tech..

[WanderingKid]

I just liked the challenge of it and decided to chase it since I managed my Mun orbit for science and achievement without any upgrades so far.  Also a little bit of "Well, screw you then" to the game since the docking ports are in Tier 5 to achieve the next milestone mission, and that's just the Juniors.  Regular Docking Ports are up in T6 after upgrades.

I've personally been hitting a wall ~1660 kps orbital speed trying to bring up the 2 man crew cabin, so I've seen what you're talking about, and that's using a Terrier after a slow climb to 10k to get it to ~51Kn pressure.  The part count has always been a nasty wall for spaceplanes, similar to tonnage on rockets being the wall.

The Nacelle + Wheesley might have enough at 120 Kn to lower the part count significantly enough that I could pull it off at Tech 5 (90).  That would strip off 12 parts for the 4x Juno/intake/mini tank assemblies, and allow me to shift around some of the design to be more compact.  I just kept hoping I was missing something.

[Leafbaron]

I managed to make a plane with the d-v to get to orbit according to MJ with 18t and 30 part limit. however, I couldn't get the balance right so after burning jet fuel it would flip over. Because of the design with the LFO in the back I had to keep the CoL and CoM very close so after burning all LFO I didn't have a lawn dart. When I finally got the plane to get above 15km, I realized soon i'd have no control authority because no RCS. Scrapped the idea and decided Spaceplanes are not meant to have part limits and weight restrictions. 

[moronwrocket]

@Leafbaron - Every cockpit has a small reaction wheel, so you'd have some control authority. Might not be super fast, but should be possible. 

 

@WanderingKid - Haven't tried much with spaceplanes in 1.2 yet. Have you considered slicing the plane in two and letting it dock on the landing strip before launch? I've done something similar, except with a payload in the middle http://imgur.com/a/vYnGC It might be possible to do this with two initially separated vehicles, but the first one on the strip would have to roll backwards until it is far enough away the UI lets you put another vehicle down.  It might be easier to do 3 slices longwise: left wing, center cockpit + rocket, right wing.

Sounds impossible, but would be very Kerbal!

Another possibility is to make your spaceplane with <30 parts but needing >18t with fuel, deploying it to the landing strip empty, and roll up a separate ground vehicle to fuel it up. That seems a bit more possible.

 

[Leafbaron]

2 minutes ago, moronwrocket said:

@Leafbaron - Every cockpit has a small reaction wheel, so you'd have some control authority. Might not be super fast, but should be possible. 

 

@WanderingKid - Haven't tried much with spaceplanes in 1.2 yet. Have you considered slicing the plane in two and letting it dock on the landing strip before launch? I've done something similar, except with a payload in the middle http://imgur.com/a/vYnGC It might be possible to do this with two initially separated vehicles, but the first one on the strip would have to roll backwards until it is far enough away the UI lets you put another vehicle down.  It might be easier to do 3 slices longwise: left wing, center cockpit + rocket, right wing.

Sounds impossible, but would be very Kerbal!

Another possibility is to make your spaceplane with <30 parts but needing >18t with fuel, deploying it to the landing strip empty, and roll up a separate ground vehicle to fuel it up. That seems a bit more possible.

 

What a creative solution to the Intial part limit! +1 sir. 

[Yakuzi]

If you are looking for a low tech SSTO (but not necessarily a spaceplane), the amazing @Kergarin posted a video on making a fully recoverable SSTO from the first launch in career mode. You only need to unlock one tech node (described in Kergarin's video below):

 

 

[WanderingKid]

@Wrocket: That actually sounds like a lot of fun, I might have to try that for giggles.  Need to use Junior docking ports and rolling over to it might be curious without rover parts yet, but that could be interesting too!

@Yakuzi: *picks jaw up off floor* Um, thanks for that.  Wow.  Just wow.  Every time I start thinking I'm good I see stuff like that!

[kunok]

42 minutes ago, Yakuzi said:

If you are looking for a low tech SSTO (but not necessarily a spaceplane), the amazing @Kergarin posted a video on making a fully recoverable SSTO from the first launch in career mode. You only need to unlock one tech node (described in Kergarin's video below):

 

 

Hey, I did that a lot of times, designed by myself, but I still can't into ssto low tech spaceplanes

[Vaporized Steel]

@moronwrocket

Your suggestion to launch multiple vessels on the runway and docking them together is great, something I like to do myself, so thanks for the thought.

As for doing this in early career you should mind the following if you haven't already.
If you can make something that works you still run into the problem that once you recover the vessel back on the runway that you have to reassemble it for another mission. Not that this is your intention or that of Wanderingkid, just saying the obvious. Also I'd advice if you were to try this to test that vessel in a sandbox game with unrestricted part count to test the whole assembly.
You don't want to launch 2,3 or 4 seperate vessels, dock them on the ground after fiddling with your keyboard buttons to find out the vessel crashes after takeoff, or anywhere from there and in between landing after reentry.
Probably obvious advice you were going to run into anyway if you'd have taken a shot at this.

As for Kergarin's video. Rockets are definitely more of a feasible method with your criteria.

[suicidejunkie]

If you're assembling an SSTO spaceplane, then simply don't recover it (just recover the pilot from EVA for the science and XP).  Just add one more docking port to the design, refuel (and recrew) it with a truck on the lawn and send it back up!

[Vanamonde]

This is going to end up being a craft sharing thread, and so it has been moved to Spacecraft Exchange. 

[KerikBalm]

I don't think this meets all the tech level requirements (for some reason, those small tanks are at the 90 science tier, no? the intake is also much higher, as is the probe core, but maybe another one could susbstitute)....

24 part could, but it had a launch dolly that adds parts... don't know if it could be made to work with just 6 more parts.... but its certainly less than 18 tons...

[Mesklin]

Here is my old, extremely low tech rocket SSTO: one man to orbit and back (dV on orbit ~300m/s), full recoverable, can fly in full auto mode for rescue operation, equipped with some science. Can land intact on water and ground. I made it for KSP 1.0.4 but in 1.2 this thing is flying very well. KerbalX link: https://kerbalx.com/Mesklin/SSTO-Spaghetti-Low-tech-Sc

Edited October 22, 2016 by Mesklin

[xiziz]

One thing is for sure, its not impossible! Impractical, yes. Fun? Very. Probably very hard without Aerodynamics though, the inline cockpit, NCS adapter and small nosecone have very low drag combined, and the small nosecone is a great mounting point for radial engines.

Long time since I posted. I haven't been able to do T4, but T5, Aerodynamics, Landing Systems, Fuel Systems and Propulsion Systems. Well, I still need to land. I think the key is drag and thrust management, until I replaced the AV-T1 tail with a basic fin I was just shy of orbit. Blasting full thrust on rocket stage leaves me short. 4 Junos take me to Mach 1 @ 8500m, kick in the 2 Sparks and 1 terrier and lift to 15deg. Jets flame out at about 18km, mach 2.2. Keep the sparks on until TWR is about 1.65 then cut them. Keep the terrier at TWR of 1-1.2 by reducing throttle and follow prograde. Cut at about apo 67km, lift will bring it up over 70km.

Might get a little better if I remove the tail fin completely. I have used interstellar fuel switch to make the size0 LF tanks hold lf/ox 45/55 each. Equal to a FL-T100. So could save a part by installing a FL-T200 instead. I don't know if you can surface attach small intakes without editor extensions either.

Spoiler

Lets see if the picture works, can't find the preview button anymore.

Edited December 21, 2016 by xiziz
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