Skylon: It's pretty legit.

[Raideur Ng]

I must say the Skylon design is an incredible SSTO. Using sharp fairings for a highly heat resistant nose, this can achieve 1500+ m/s before close cycle. In a test with no payload, it flew into orbit, deorbited, perform a touch and go on land, back into orbit, and back down with less than it's default fuel. Streamlining seems to be the king of the land now. Thoughts? Craft file here.

Skylon Tester

• Wet Mass: 54.9 T
  • Dry Mass: 20.9 T
  • Liquid Fuel: 20.3 T
  • Oxidizer: 13.8 T
• HECS2 Core
  • 1000 Ec
• 4x Rapier Engines + Precoolers
  • Takeoff TWR: 0.58
• Max Payload to LKO: 15 T

Edited November 29, 2016 by Raideur Ng

[duk]

Dang that looks nice. Good Job!

[Spacetraindriver]

(Reply here to remind me to like tomorrow)

Man if only those doors didn't clip through the engines! Is it possible to carry crew/passengers via payload or craft itself?

[SHiftER2O]

Now make it bigger!

[Raideur Ng]

Okay, I made it bigger: Craft File The cargo bay also doesn't clip anymore. 30 tons max or whatever you feel ballsy enough to try with.

[Exothermos]

It's capable of a lot more than 30 tons!  Nice simple design.

Also interesting to me was the inclusion of a nosecone offset on the back of the Rapiers.  That was deemed no longer beneficial a couple versions back, but my tests in 1.2.1 confirm that they do, indeed, work in this version.  Now whether the weight penalty is worth it is a different calculation, i suppose.

[fourfa]

well, that's simple.  And takes care of every possible symmetry issue

[SHiftER2O]

On 11/30/2016 at 1:59 PM, Raideur Ng said:

Okay, I made it bigger: Craft File The cargo bay also doesn't clip anymore. 30 tons max or whatever you feel ballsy enough to try with.

This is such a unique heavy lifter SSTO. It practically renders most of those engine-combusted power-monger types impractical with its simplicity and all!

[Raideur Ng]

Val has built vehicles like this before and much of the design it based on their very heavy designs. I'd check them out here. However, I've not seen anyone use the fairing for a nosecone, nor the HECS2 probe core (looking at the stats of both, why wouldn't you?). It also can hide a docking port under that fairing so you can offload fuel in a tanker configuration.

[ruiluth]

On 11/29/2016 at 11:05 PM, Exothermos said:

Also interesting to me was the inclusion of a nosecone offset on the back of the Rapiers.  That was deemed no longer beneficial a couple versions back, but my tests in 1.2.1 confirm that they do, indeed, work in this version.  Now whether the weight penalty is worth it is a different calculation, i suppose.

My testing indicates that there's actually very little difference between the "rapierspike" and just a regular rapier. How did you test it?

[Matuchkin]

1 hour ago, ruiluth said:

My testing indicates that there's actually very little difference between the "rapierspike" and just a regular rapier. How did you test it?

There's this very cool thread around, in which a player does experiments with this type of thing. I'll try to fish it out here.

On 30/11/2016 at 0:59 AM, Raideur Ng said:

Okay, I made it bigger: Craft File The cargo bay also doesn't clip anymore. 30 tons max or whatever you feel ballsy enough to try with.

"I'm a simple man. Double the fuselage, double the wings. Triple the fuselage, triple the wings. No need to fuss about for half an hour."

[Exothermos]

3 hours ago, ruiluth said:

My testing indicates that there's actually very little difference between the "rapierspike" and just a regular rapier. How did you test it?

Well, if it is a reliable indicator (and I think it is) there is a pretty noticeable difference by looking at the f12 aerodynamic overlay while in flight.

This is a "Rapier-cone" test plane with one plain rapier (starboard), one rapier with a nose cone offset into it (port), and one open node (centerline) as a baseline control.

We are near sealevel here at a little over 300 m/s.  It's a pretty significant difference in drag with the nosecone installed.  In fact the rapier is nearly as bad as having an open node, which was surprising.

Here is the same thing with a "rapier-spike"

This is all super important now as it seems the sealevel "scud-run" is the best way to build up velocity in rapier powered craft.  Obviously drag is critical in the thick lower atmosphere.  This flight profile is how some of the more deft SSTO builders here (like Val and Rune) are able to get such awesome performance out of really simple designs with low TWR. Raidur Ng's design here follows those principles of streamlining, simplicity, and relatively low TWR.  And yes, fairings are an awesome choice for the pointy ends thanks to their heat resistance (2600 degrees), but other things work well too if you are careful.

Edited December 2, 2016 by Exothermos
Clarity