25 Kerbal Single Stage to Laythe and Back (No Refueling) Stock Spaceplane!

[TechniCali]

Seeking to top my previous results from my Laythe Cruise Line Challenge, I sought to build a large cruise liner craft that could take the largest possible number of Kerbals to the surface of Laythe and back to KSC in a fully sustainable manner: 100% reusable, Single stage (no landers or transfer vehicles), and without the need to refuel at any point in the journey (luxury cruise line passengers don't like waiting around for refueling). I also wanted it to be fully stock. I found that meeting most of these requirements was a good challenge, but that meeting all of them at once was very difficult.

I'm proud to present my greatest acheivement in KSP: the Laythe Cruise Liner Stock XR (Extended Range). It can bring 25 Kerbals from KSC to the surface of Laythe and back in a single craft with zero staging, and no need to refuel. It has great lift and can take off at low speeds close to 60 m/s, and can glide for very long distances. It does not use any cheats or clipping exploits to acheive its performance.

See below for details of the journey and information on the craft, and let me know what you think!

The Journey to Laythe and Back

I'll try to show screenshots or callouts of the fuel level at each milestone in the journey – fuel was tight on the way back, as I spent too much travelling around on Laythe and landed back at KSC with only 10 units of liquid fuel remaining – fortunately I was able to glide in from orbit totally unpowered due to the great amount of lift on this craft, even after having overshot the space center, needing to turn around.

Takeoff from KSC- 17,250 liquid fuel

Suborbital

Kicking off the jets and moving to rockets around 1700 m/s and 33,000. 12,915 liquid fuel remains.

Burning for Jool:

Laythe Intercept:

I got a direct encounter with Laythe without needing to aerobrake at Jool, so I had to make 1 shallow aerobrake pass first before going in for a landing. Going in many km/s too fast could rip the wings off the plane, so I usually like to circularize via aerobraking first, and then go in to land on the second pass.

Aerobraking: 3749 fuel left.

Landing:

Triumph!

A group shot with all 25 passengers!: 3413 liquid fuel left

Laythe Takeoff:

I messed up here by landing on an island very far south and burning a lot of fuel to get there. I wanted an equatorial orbit to return to Kerbin, and didn't want to use rockets to change my inclination in orbit. So instead, I flew north on a sub-orbital trajectory on jets alone first to get to the equator, re-entered, and then turned east and re-orbited – I think using jets only to do this was more efficient, but this was wasteful of fuel.

Return burn:

I performed a more efficient transfer back to Kerbin directly from Laythe orbit by calculating manually, rather than first going to Jool orbit. Only 282 liquid fuel remained at this point, and the correction burn took me down to around 150.

De-orbiting at Kerbin:

After another 2 pass aerobraking back at Kerbin, I was forced to stick with my entry periapsis on the dark side of Kerbin due to low fuel. After adjusting my aim for KSC and doing a de-orbit burn, only 13 liquid fuel remained! This meant I would need to glide in.

Overshot it!

I overshot KSC by quite a way, so I needed to glide past, turn around, and land from the ocean side instead:

Landing as a glider:

Landing lights on, crawling along at ~40 m/s – gotta love the low stall speed on this craft

Landed!

8 fuel remain after taxiing close to the SPH:

Craft Details

Craft File

The Laythe Cruises Fleet includes these are the crafts:

• Laythe Cruise Liner Stock XR (Extended Range)
  The flagship 100% re-usable stock Laythe Cruise Liner that can bring 25 Kerbals to Laythe and Back without shedding any parts and without the need to refuel.
  
• Laythe Cruise Liner Stock
  A perfectly balanced version of the cruise liner with less fuel and less thrust. Must refuel in LKO before going to Laythe in order to comfortably make it. Slightly more maneverable than the XR version.
  

• Laythe Cruise Liner Prime (you'll also need SpacePlane Plus)
  A 10 Kerbal ship that is much sleeker and more beautiful. Must refuel in LKO before going to Laythe, but is 100% re-usable.
  

• Laythe Cruise Liner Refueler (you'll also need SpacePlane Plus)
  A handy 100% re-usable refueler spaceplane used to sustainably refuel the second and third craft above.
  

Craft Notes:

1. I've included versions with MechJeb mounted as well – indicated with "MJ" in the title.
   
2. The XR craft has thrust that is very slightly above the Center of Mass. This wasn't a problem for me, as SAS was able to easily dial out the difference. The top tanks and engines that cause the imbalance are necessary to provide the extra fuel to get to Laythe and back without the need to refuel, and the extra thrust needed to lift it all off of Kerbin. I only used the extra engines on ascent from Kerbin so that otherwise the craft was always perfectly balanced. If you know you'll just refuel anyway, you can ignore the XR version and just take the normal craft (second one above), which is perfectly balanced around the CoM.
   

Operation Instructions:

Hotkeys:

1: Rapier engines group 1 toggle on/off

2: Rapier engines group 2 toggle on/off

3: Jet engines group 1 toggle on/off (includes the COM-imbalanced engines on the XR craft)

4: Jet engines group 2 toggle on/off

5: Switch Rapier modes

6: Toggle intakes

7: Toggle rear “tailstrike prevention†gear (raise it before takeoff)

8: Deploy ladders

9: Deploy solar panels

0: Nuclear Engines toggle on/off

Press spacebar, then press 6 to close intakes to limit drag. Raise the rear landing gear for takeoff. Ascend at a 50 degree angle to 15,000, and then climb at a 30 degree angle. Start leveling out more and more as you climb towards 30,000, opening intakes when needed to prevent flame outs. Around 1,700 m/s and 31,000, press 3 and 4 to turn off the 8 jet engines to allow more air for the remaining Rapier jets. Later, turn the rapiers on rocket mode with 5, and re-enable group 2 of jet engines. Finally, turn off the jets, kick on the nukes, and turn off the rapiers when their thrust is no longer necessary.

Edited July 16, 2014 by TechniCali

[Oafman]

Very impressive. I love to see potential intake air of 13.20!

[Duke23]

Holy kraken bait Batman. That is awesome... I've seen people do some some crazy things around here but to do that stock with no clipping or intake spamming (well, you know what I mean) that I can see is very impressive. I still haven't managed to make a single stage to Mun and back spaceplane and my SSTOs generally carry 2-6 Kerbals.

[QPDO]

What a Stock-Shock!

Have you tried that Monster with FAR ?

[KerikBalm]

Hmm, I woulda stuck some ions on there for those correction burns, but on the other hand....

While SSTO is cool, I really don't see the point - aside from the challenge (good job btw, I also try to make SSTOs with no clipping, I consider part clipping to be an exploit) when you can do 100% reusable multi stage craft.

Considering the travel time of years, I really don't see the problem with waiting 30 minutes for an SSTO refueler to top up the craft before going to laythe, nor waiting 30 minutes to rendevous with a fuel cache left in orbit before descent to the laythe surface.

So far I've only done no part clipping heavy lifter SSTOs that take a laythe mission payload to LKO, and the laythe mission payload consists of a transfer stage and a laythe 2 person SSTO lander.

Everything can be brought back to kerbin and refueled... but... I never tried to land such a large craft on Laythe.

My Lifter did have enough dV to do a free return flyby of the Mun after delivering a 100ton payload to LKO... I wonder if it could do it if it just carried 100 tons of fuel tanks and Kerbals (it might be hard to design a suitable payload that would fit in the payload area though)

[Khobai]

very impressive considering no part clipping.

part clipping is definitely cheating because parts have different volumes for a reason and when you clip them you defeat the intention behind parts having different volumes.

[Cirocco]

Holy mother of Kraken that's impressive.

I've messed around with stock, no (or at least very minimal) clipping, interplanetary SSTO spaceplanes as well (though I have only done Duna surface so far) but only with 1 or 3 man crews. Never did I dream that a 25 crew interplanetary transporter could be done in a stock SSTO spaceplane without part clipping.

Very, very impressive.