Skylon

[Youen]

This is my work in progress to reproduce (or just produce since it has never been built yet) the Skylon SSTO spaceplane design. Not really possible to do with current mods, so I'm modding the mods as well

The goal is to add the near-future technologies needed for realistic SSTO spaceplanes in KSP.

Current state:

• B9 SABRE engines are not powerful enough [fixed] by creating a new scaled up part, all dimensions of M engine multiplied by 2, Area parameter of AJE multiplied by 4, mass was already correct (14t for intake + body + engine)
• The design is not aerodynamicall stable (don't know if FAR is not realistic enough or if my craft does not match the Skylon shape and mass repartition) [fixed] by moving wings to the back and increasing the tail aileron vertical surface ; also adjusted engines inclination and vertical offset
• RO / Procedural Parts shielded fuel tanks are too heavy, and BalloonCryo type is not heat resistant [fixed] by adding a new tank type that matches the Skylon material (carbon-fiber reinforced frame, aluminium internal tanks, ceramic skin for heat shielding). I've tuned the mass so that it matches the projected 53t when empty, and set the skin heat resistance to 1500K (arbitrarily, they say it shouldn't exceed 1100K during reentry but the real thing surely needs some margin)
• Not enough drag during reentry, not slowing down enough (this is probably a FAR issue, I'm really far from the projected Skylon reentry profile)
• Too much heating during reentry (even when following the above linked reentry profile by adjusting velocity with HyperEdit, too much heat is generated, way above 1500K)
• Need to adjust fuel quantities to reach orbit with a 15t payload
• Current modelisation of the SABRE engine with Advanced Jet Engines is made so that Isp is unrealistic when throttling down in air-breathing mode (it goes up to 10 000s at 2/3, but should be arround 4 000s)
• The runway is too short (can be worked-around by taking off from the grass, or just hoping it won't break when falling down the end of the runway, and take off before falling in the sea)

Let me know what you think or if someone already made a similar craft with Realism Overhaul?

Edited April 19, 2016 by Youen

[Majorjim!]

I'm not a fan of part mods but that is one stunning looking spaceplane!

[Knotty]

Explains why my stock attempt at this failed so miserably...

[Youen]

3 hours ago, Knotty said:

Explains why my stock attempt at this failed so miserably...

By "stock" you mean without RO/RSS? In this case you should need less delta-v (but still quite a big spaceplane I guess).

On 19/04/2016 at 11:28 PM, Majorjim said:

I'm not a fan of part mods but that is one stunning looking spaceplane!

I'm not a fan of part mods either (at least those that add a lot of pieces), but I really like procedural mods (wings and fuel tanks). For example Procedural Parts adds just a few parts, that can replace all the stock fuel tanks, shields, batteries, etc, and allow more control than all those parts. I also love TweakScale. The next step would be to remove the stock parts that become useless (unless you still have saved ships using them of course). I'm sure a modded install oriented toward procedural parts would require only a handful of parts and would be way more complete than the stock game.

And sometimes to get just a part I want I have to install a mod that adds a lot of less usefull stuff (I could also remove the unecessary parts but that's a bit tedious).