Munar Cruise Line Challenge! 100% Re-usable SSTO from KSC to Munar surface in style!

[TechniCali]

Munar Cruise Line Challenge!

As a challenge for myself, I wanted to see if it was possible to make a sustainable, 100% re-usable “cruise line†that could take a large number of Kerbal tourists from KSC to the Munar surface and back without the need to refuel or shed any stages/equipment. I'm pretty happy with the result, but would love to see what else the community can invent. Below are the rules, and my “brochure†for the cruise line, containing the details of my craft.

Also - I would love to attach .craft files, but the forum says that I may not post attachments - any ideas why?

Rules/Acheivements (10 points for each rule you successfully follow):

• The Love Boat: This is a cruise line – at least 10 passengers to allow proper socializing.
  
• Home Airport: Take off from KSC and land at KSC with the same passengers you left with.
  
• Fully Intact: 100% re-usable craft: no staging (except to isolate engines you don't want to turn on at first, etc) – return with everything brought with you. A cruise line can't afford a new ship for each cruise.
  
• Gas Stations Suck: No refueling in-flight – luxury cruise line passengers don't want to hang around space stations. Besides, using non-reusable rockets to fuel a space station to refuel your SSTO violates the Fully Intact rule.
  
• Everybody gets to see the Mun: Allow at least 1/3 of your passengers to land on the Mun.
  
• Off road spaceplane: Make a craft capable of landing on rough surfaces and hills. After all, we're thinking of expanding to Laythe one day, and you never know when running low on fuel means you'll miss the KSC runway.
  
• STOL: Build a Short Takeoff and Landing craft with enough lift to take off and land under 75 m/s, allowing easier access to hilly areas.
  
• What's a tailstrike?: Build a tailstrike-proof spaceplane that cannot possibly destroy an engine on takeoff or landing despite high angle of attack.
  
• Out There: Build a craft capable of tourism to celestial bodies beyond Kerbin's SOI
  
• Marketing Whiz: Your entry should ideally be submitted as a brochure with pictures or video showing your craft in action, advertising the features and luxury of your craft, with a FAQ (Frequently Asked Questions) at the end.
  
• Harmless Mods: You may use mods, but none that give an advantage in achieving the mission vs. stock parts. For reference, I used PorkJet's excellent SpacePlane Plus to get access to a cargo bay and make the craft look beautiful, but since the air intakes on the mod are slightly more efficient than stock, I also built a fully stock craft to prove that I could achieve the same result without the mod.
  
• She's a Beaut!: Make a craft the forum considers attractive
  
• Fine Tuned: If you build a spaceplane, it should be able to climb or maintain altitude with the nose no more than 10 degrees above prograde.
  
• No cheating: Obviously this means no hacks, physics exploits, etc. However, it also means no clipping exploits that allow multiple air intakes to be stacked on top of one another. Violation of this rule is the only one that means zero points.
  

My Brochure for Munar Cruise Lines:

Has the daily grind of life on Kerbin got you down? Need to get away this summer? It's time to get away from it all - really far away - with a fabulous Cruise on Munar Cruise Lines!

You and 10 of your closest friends will spirited away on an all-inclusive cruise to the Mun, where you each will get the experience of a lifetime - landing on the Mun! Best of all - you can take off from the comfort of Kerbal Spaceport in an eco-friendly, 100% re-usable spaceplane with all the modern amenities, with no pesky "layovers" at space stations for refueling.

It's always a party with up to 11 passengers!

Soar to over 30km at over 1,750 m/s on jet power alone, leaving over 3,500 deltav to take you to the Mun and Minmus:

The lander stored in the cargo bay will dock with the in-line docking port for easy crew transfer, and all of that extra deltav will allow several trips down to the Munar surface for your party, refueling each time the lander returns!

Life is great on the Mun:

Frequently Asked Questions:

Q: Why did our engineers decide to use PorkJet's amazing SpacePlane Plus to construct our cruise liner rather than a stock craft?

1. We needed a Cargo Bay for the Munar Lander, and SpacePlane Plus has a great cargo bay for Spaceplanes
   
2. We built a stock craft that can achieve this mission (actually exceeding the modded craft with 4,500 delta-v remaining at 90k Kerbin orbit), but it was U.G.L.Y. - it had absolutely no alibi:
   

Q: What other mods did you use?

A: Just NavyFish's Docking Port Alignment cam, and MechJeb for telemetry. Modless craft files will be available (aside from SpacePlane Plus, which will be required).

Q: What does the lander look like? Was it hard to fit in the cargo bay?

A: Yes – it was hard. We had to totally redesign the concept of a munar lander to fit it in a narrow cargo bay, even mounting landing legs on tiny fuel tanks and turning it 90 degrees sideways so the ladder would fit in the cargo bay without clipping. This is what it looks like in our hangar:

Q: What if I want to travel to another planet's moon?

A: Coming soon, you'll be able to try Munar Cruise Line's XR (Extended Range) ship, which can much more easily dock to refuel from another fully re-usable ship while in Kerbin orbit (docking port aligned to center of mass), providing over 5,400 deltav for travel to many of the planets in the solar system:

Q: How do I know I'll be sage traveling Munar Cruise Lines?

A: Most spaceplane accidents don't happen in space - they happen close to the ground - often when landing or taking off. Our ships fly like a dream, take off and land quickly on short, rough surfaces, and can take a beating. They have ruggedized landing gear that allow touchdowns at high vertical and forward speeds, exceeding 20 m/s of vertical drop. They also have gear that prevents the possibility of a tail strike if landing at an extreme angle. Finally, by lowering the rear landing gear, our ships can take off within only a few hundred meters at slow speeds under 70 m/s, allowing landing and take off in very hilly areas:

Q: Are your ships actually X-wings from Star Wars with their wings closed?

A: I don't know what you're talking about...

Happy Cruising!

Craft File:

Coming soon (as soon as the forum lets me upload attachments)

Operation Instructions:

Hotkeys:

1: Rapier engines toggle on/off

2: Jet engines toggle on/off

3: Switch Rapier modes

4: Toggle main on-wing circular intakes

5: Toggle secondary structural intakes

6: Toggle tertiary structural intakes

7: Toggle rear “tailstrike prevention†gear

8: Open cargo bay doors

9: Deploy solar panels

0: Nuclear Engines toggle on/off

Press spacebar, then press 4,5,6, and 7 to close all but the bottom intakes and 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 as needed to prevent flame outs. Around 1,700 m/s and 29,000, press 2 to turn off the 4 jet engines to allow more air for the remaining Rapier jets. Around 1,750 and 30,000, press 3 and 0 to engage all rockets.

Important Lander Note: Enable RCS and SAS just before touchdown if not already on – the RCS is necessary to stabilize the rather tall lander. The lander's height is an engineering limitation forced by the very narrow cargo bay.

Thanks for indulging my first KSP post!

[Sirine]

As a challenge for myself, I wanted to see if it was possible to make a sustainable, 100% re-usable “cruise line†that could take a large number of Kerbal tourists from KSC to the Munar surface and back without the need to refuel or shed any stages/equipment.

You did refuel the Mun lander at every Mun surface <-> Space plane(Cruise) route. right? And you did deploy the Mun lander, hence consider a stage?

Further more, you did not show how your cruise are going to back to KSC, the technical difficulty here are when your fuel are depleted your COM will shift, causing your cruise to be unstable, compair with while its lift-off from KSC.

Note: forum will never allow attachment. Try using 3rd party hosting site, such as www.

[micha]

First of all, that's a very nifty spaceplane/lander combo!

But the "Fully Reusable" category does state "no staging" and I concur that the lander is a stage, even if you do redock it and land it back on Kerbin. Otherwise extending this concept you could leave various parts of your craft in various orbits, collecting them on the return journey for landing, and still be within the rules of this challenge. Eg, a heavy launcher, left in LKO, a cruise stage left in LMO, and the lander stage.

Or in fact extend it to the concept of leaving a "cruise stage" in permanent Kerbin-Mun orbit which transfer craft dock to. The idea being you only need a small capsule to get to/from the cruise stage, and the cruise stage itself contains large living quarters and all other amenities. So instead of having to haul the cruise-stage in-and-out of gravity wells all the time, you leave it on a transfer orbit. This was a real design for an Earth-Mars transfer system. The problem being that you have to wait for an entire orbit for the return journey, or you need a whole chain of these cruise stages.

Anyway, back on topic, I guess the challenge needs clarification - is it a "100% reusable" challenge, or a "SST Mun-and-back" challenge?

[eempc]

It's a nice, simple challenge, whether or not you use the lander-loophole.

FAR-certified space bus taxi thing. It was originally designed for Duna operations but it seems to cut the DV requirements a bit too close for my liking (3600 once in LKO). It handles Mun outings fine though.

There's not much margin for error with the take off angle.

RAPIERS and LV-N to generate an apoapsis. After which, the RAPIERS are switched off and only the LV-Ns circularise the orbit.

There were 2 empty seats on the bus because there weren't enough kerbals available. They were all sent up on pointless LKO test missions and never returned. They now pose a hazard for launches.

Retrograde burns for landing.

Transition to vertical.

Belly flop onto landing gears.

Group shot.

Since I landed in a crater, I had either the option to taxi to the edge of the crater and use it as a ramp or just use the VTOL engines. I chose the latter.

And away we go.

Time to head back now.

Atmospheric entry. FAR destroyed my plane three times at this part and I had to rage-reload and enter in at different angles.

Close call with the mountains west of KSC.

Didn't even have to use the emergency drogue chute for the landing.

Edited July 8, 2014 by eempc

[MircoMars]

But the "Fully Reusable" category does state "no staging" and I concur that the lander is a stage, even if you do redock it and land it back on Kerbin. Otherwise extending this concept you could leave various parts of your craft in various orbits, collecting them on the return journey for landing, and still be within the rules of this challenge. Eg, a heavy launcher, left in LKO, a cruise stage left in LMO, and the lander stage.

actually it says SSTO, implying Kerbin orbit. perhaps SSMR (SingleStageMunarReturn) could be hard mode

[ihtoit]

hmmm... very old design, but...

Luke Kerman brings relief to 20 stranded Kerbals on Mun in a true SSTM: Munbase Beta:

(Alpha held 20/38 Kerbals but a bad landing meant that it couldn't take off again. Beta was sent as a rescue vehicle and actually managed to land 4km from Alpha).

Both vehicles held enough fuel for a round trip with fuel to spare. In fact, Beta did a stopover on Minmus once the rescue was complete and still had fuel left after a successful return to KSC.

All but the spaceplane awards. Yes, it's a VTOL, yes it uses NERVA rockets. It doesn't say anywhere that it can't be not a spaceplane nor does it restrict propulsion type.

[Sirine]

It's a nice, simple challenge, whether or not you use the lander-loophole.

FAR-certified space bus taxi thing. It was originally designed for Duna operations but it seems to cut the DV requirements a bit too close for my liking (3600 once in LKO). It handles Mun outings fine though.

I have try to duplicate your plane. But it seems that there are something that I'm missing.

F.A.R or without F.A.R. Can't even make it to Kerbin Orbit.

Perhaps you could enlighten me?

Craft file Here.

Edited July 9, 2014 by Sirine

[eempc]

Did you try it without F.A.R.?

I did test the design on stock aerodynamics but after losing the LV-Ns to tail strike, running off the runway and flopping into the water I preferred the FAR design. For stock, you would need more wing area to generate lift, either by altering the planform or sandwiching more layers. It would also need more intakes to get high altitude performance.

[DeathSabre]

IS FAR allowed? I thought it would give you an advantage.

Do passengers need to be in a closed capsule? or are command seats valid?

[eempc]

IS FAR allowed? I thought it would give you an advantage.

From my experiences with FAR, the only positive aspect is that I can get a larger amount of spare DV once in LKO, but since this is a Mun mission, DV isn't a huge issue whether you go stock or FAR. The downsides to FAR are that planes must be built aerodynamically, i.e. no more flying boxes. You also cannot deviate from prograde too much so if you don't provide enough lift and thrust with <20 degree AoA, your plane will likely fall apart trying to maintain vertical speed. Atmospheric entry into Laythe was also unforgiving. I found out the hard way that FAR will destroy your plane if you re-enter at Mach 36.

I have try to duplicate your plane. But it seems that there are something that I'm missing.

F.A.R or without F.A.R. Can't even make it to Kerbin Orbit.

Perhaps you could enlighten me?

Craft file Here.

It's not a straightfoward construction. The intakes and engines have to placed in a particular order to induce symmetrical flameout, which was explained here http://forum.kerbalspaceprogram.com/threads/84217-Explaining-burnout-asymetry. But in short, you place in this order: outer left shock intake, left engine nacelle, left RAPIER, inner left shock intake, left turbojet, outer right shock intake, right nacelle, right RAPIER, inner right shock intake, and lastly right turbojet. This does mean that the rear tailfins and landing gears need to be placed individually.

The RAPIERS are in manual switching mode too.

The two outer fuel tanks have 396 oxidiser, and the central rear bicoupler tank has 0 oxidiser.

There are 6 VTOL engines on the belly that are hard to see in the picture since only their nozzles stick out, but they are rockomax 48-7S mounted on cubic struts. I can't say these are critical for the Mun, because this plane was designed for Duna originally. Getting the right vertical direction of thrust when placing these engines is a bit of trial-and-error, but any instability from using the VTOLs can be compensated by the reaction wheels.

You can also see the fuel lines. While I am not an expert on fuel flow, this way generally ensures that fuel is drained from the back first, thereby ensuring the CoM always moves forward and remains ahead of the CoL.

I name my planforms after gemstones and this "Amethyst" is very versatile, you can swap the 3 crew cabins for any combination of cargo bays, fuel tanks or cabins up to around 10-12 tons. Here is an example of the cargo version with an integrated kethane unit (the hidden drill was the most ingenious part), a separate kethane ion probe, and some TAC supplies.

The keys I use are: (1) toggle RAPIERs on/off, (2) toggle turbojets, (3) toggle RAPIERS between rocket and air mode (4) toggle LV-Ns, and (6) toggle all intakes

As for piloting the plane upwards (FAR), you can just maintain full throttle at ~20-25 degree pitch all the way up using the four air breathers. Maybe pitch down to 10-15 degrees at 20 km. The RAPIERs may flameout but they will flameout together because of the way the intakes and engines are placed in order. The RAPIERs are in manual switch mode, don't let them switch to rocket mode until later. Turn off the RAPIERS with (1). You should be at least 1,600 m/s orbital speed by now.

After this, you are running on two turbojets only. At this point, your pitch sort of depends on what's happening and usually oscillates around 5-16 degrees, which corresponds to around ~10-12 degrees angle of attack. The next objective is to reach an orbital speed of 1,700 m/s with the turbojets alone (i.e. as fast as possible), but I'm usually fine with anything above 1,650 m/s. You can maintain full throttle even as the intakes struggle, again because of symmetrical flameout. I also try not to lose too much vertical speed during this phase, no less than -25 m/s vertical.

When the turbojets are struggling, their thrust will drop to around ~120 kN combined. It is around this speed of 1,700 m/s and thrust of 120 kN that I turn on the LV-Ns with (4), switch the RAPIERs to rocket mode with (3) and turn on the RAPIERs with (1). All 6 engines are now firing.

When the turbojets are outputting a pitiful >30 kN, turn them off with (2) and shut off the air intakes with (6) to reduce drag. Generate an apoapsis of ~65 km and an orbital speed of 2,000-2,200 m/s with the RAPIERs + LV-N combination, then turn off the RAPIERS with (1). Use the LV-N to finish the apoapsis and circularise. You can turn off the RAPIERs sooner if you feel the LV-N are able to finish the orbital insertion.

I won't claim this is the most efficient way to pilot the plane and you are free to find any improvements by changing pitches, engine configurations, etc, but it's how I do it and end up with around 3,600 DV.

Edited July 9, 2014 by eempc

[Hodo]

So let me see if I can get this stock plus spaceplane + parts only? So whats the ruling on ECLSS life support, FAR, DRE, and other part mods.

[Sirine]

I won't claim this is the most efficient way to pilot the plane and you are free to find any improvements by changing pitches, engine configurations, etc, but it's how I do it and end up with around 3,600 DV.

I love your craft. Would you mind to share it?

Call me stupid. I can't seem to duplicate one that manage to fly to LKO.

Later Edit: Ok. I got it now...I'm installing FAR with missing the module manager and toolbar plugins...After fixing this. I manage to get the plane to LKO.

Edited July 10, 2014 by Sirine

[eempc]

I love your craft. Would you mind to share it?

Call me stupid. I can't seem to duplicate one that manage to fly to LKO.

Later Edit: Ok. I got it now...I'm installing FAR with missing the module manager and toolbar plugins...After fixing this. I manage to get the plane to LKO.

One day I might get some online storage and share files. But anyways have fun optimising and see if you can get more than 3600 m/s DV into orbit.