SSTO to Eeloo: Can it be done?

[Pds314]

The rules of this challenge are simple, using Stock, FAR, Other Realistic Aerodynamics mods (I reserve the right to judge realism and fairness), engineering/autopilot mods or all of the above, design an SSTO capable of reaching and landing on Eeloo, taking off, and returning to Kerbin or LKO.

Clarifications:

1. If it requires refueling upon reaching orbit, it doesn't beat the challenge, but feel free to post it anyway, making sure to explain that it does.

2. Try to avoid excessively long ion-fueled burns. This goes especially for burns involving under-powered ion engines. In fact, you should really just try to avoid using Ion engines altogether for sanity's sake.

3. It can be a rocket or a plane, but your prospects for a rocket look pretty bleak, as the ship will require nearly 11 km/s delta-v in one stage. Seeing as that is roughly Earth's escape velocity IRL, this is harder than making a pure-rocket-SSTO on Earth. Something that has never been accomplished in history.

4. It should be able to land in one piece back on Kerbin. Props for landing at KSC, on the runway, launchpad, helipad, SPH, bridge, or somewhere else interesting.

5. It is strongly preferred that the craft is manned and does not exploit the FTL-egg, infiniglide, or FAR Pseudo-infiniglide physics bugs for Delta-V.

Advice:

• The delta-v required to get to Low Eeloo Orbit and back after reach LKO is around 5.6 km/s. The Delta-V required to land and take back off is around 1700 m/s. combined, this is roughly 6.3 km/s required.
  
• Eeloo has about 1.7 m/s^2 gravity, if you try to land or take off using nuclear engines, make sure you have an engine for every 35 tonnes once you reach it. Remember also that gravitational drag will reduce your efficiency, so if your craft has an Eeloo-TWR of 2, expect about 70% efficiency, if you have a TWR of 3, expect better performance. This means that realistically, most ships need much greater Delta-V.
  
• If once you reach orbit, your entire nuclear-powered ship has a Mass/Dry mass ratio of 2.25-2.5 and you expect to land and take off from Eeloo completely using LV-N rockets, then it should be possible.
  

Scoring:

Scores will be based on a point system based on accomplishments of the craft. All craft that did not return to Kerbin and complete the mission are automatically capped at 999 points.

• Overshoot: escape Kerbolar Orbit BEFORE reaching Eeloo. +100
  
• Grand tour: enter the sphere of influence of Dres, Duna or Jool either on the way to or back from Eeloo. +50 per celestial.
  
• Eeloo there: Get to orbit around Eeloo. +200
  
• One cold step...: Land on Eeloo and EVA. +250
  
• Wrong way: escape Kerbolar orbit AFTER reaching Eeloo, Landing, and getting back to orbit. +150
  
• Home sweet home: Take off, Reach LKO, Go to Eeloo, Land, Take off again, get back to Kerbin or LKO. +550, your entry counts as a successful one.
  
• Reusable spacecraft: land on Kerbin intact after completing the mission with all Kerbals alive and no SRBs used. +250
  
• Recyclable spacecraft: crash-land on Kerbin with at least on Kerbal surviving. +100
  
• Spacebus bring additional Kerbals along with the pilot. +50 per Kerbal besides the pilot. They must survive to either dock and board a space station or return alive to Kerbin to count.
  
• No Kerbal left behind: If you brought multiple Kerbals, all of the additional ones survive and return to Kerbin's surface or dock with a space station and board it. doubles your spacebus score.
  
• Eeloo express: Complete the mission in under 800 days total, +1 point per day.
  
• One-way Eeloo express: get to Eeloo in under 365 days. +2 points per day.
  
• Who says planes don't work without an atmosphere: land on Eeloo with a horizontal forward velocity of 50+ m/s. +100 points
  
• Ready to go again: land at the start of the runway or on the launch pad in the correct position to launch once refueled. +200 points.
  
• Controlled landing: don't use parachutes, use wings, rockets, or sheer force of stupidity to land on Kerbin and live: +100 points.
  
• Totally harmless, mostly: Use LV-N atomic rocket motors and/or jet engines, no other solid motors or liquid fuel engines allowed. +200 points.
  
• Reversible: do the challenge forwards and prove yourself capable of doing it backwards as well, that is to say, go from Eeloo to Kerbin back to Eeloo. You can get it to Eeloo initially however you want. +500 points
  
• Good old-fashion power: do the entire challenge using only engines with a TWR of 5 or greater on Kerbin. That means no ion or nuclear engines. +1500 points.
  
• Dead-stick: land safely on Kerbin without firing your engines or using a parachute. +150 points.
  
• WTHHOWDIDYOUDOTHAT???: Do the entire mission successfully without using jet engines. +2500 points.
  
• Payload to Eeloo or Eeloo Orbit: Upon reaching Eeloo, drop a payload. Payload may not include any used rockets, landing gears spent/partially spent fuel tanks or any aerodynamic surfaces. 1 point for every 25000th of the launch mass on ground. 1 point for every 10000th in Orbit (e.g. if a 100-tonne (at launch) spacecraft deposits 1 tonne on the ground, it gets 250 points. If it deposits it in orbit, it gets 100 points). I reserve the right to call a payload a stage arbitrarily with an explanation should it seem obviously advantageous to have at launch.
  
• Budget cuts: 3 points for each 10 units of Liquid fuel or Oxidizer or Mono-propellant under 10,000 combined.
  
• Margin of Error: divide the amount of fuel+mono-propellant+oxidizer you started with by the amount spent. Subtract 1 and then multiply by 5000 points. (e.g. if you used 80% of your resources, you'd get 1250 points. If you used 50%, you'd get 5000 points.) This only applies to successful entries.
  

Edited December 9, 2013 by Pds314

[stupid_chris]

That sounds interesting. Time to download FAR.

Oh, and is RealChute allowed?

Oh, and necessary note:

How does one win? Any points system, marking way, voting schedule, etc? And we would need to see an attempt from you for good measure

Edited December 8, 2013 by stupid_chris

[Pds314]

RealChute is okay. BTW, FAR is not a requirement for the challenge, but it helps tremendously with getting big aircraft to take off.

I currently am still in the process of making my attempt. I guess in terms of rankings, I will revise the Original Post and come up with a system.

[Moar Boosters]

I think it's definitely possible.

This is 100% stock and doesn't use ion engines. It was just an encounter and then we went back home, but I built this SSTO before I knew about stacking ram-intakes. It's got about a billion radial ones tucked under the wings.

I'm sure a more efficient design would be able to achieve orbit, and then probably sending down a tiny detachable lander to take them to the surface and back.

[FacticiusVir]

I'll be really interested to see if/how OP manages this; I've been stuck trying to get an SSTO to the Mün and back. I just can't find a balance of enough fuel/jets to fly into Kerbin orbit, and enough fuel/low enough mass to get back up off the Mün. FAR might change that though, as I'm playing without mods.

[Pds314]

Nice! Of course, sending a lander down still is less than what is required. The ship itself needs to land.

[epursimuove]

Does the entire ship need to land on Eeloo?

[Pds314]

@facticiusVir: I have seen a stock ssto reach Laythe, deposit a sizeable payload to the ground and return before. Granted, aerobraking and aatmospheric Oxygen make that much easier to do compared to on Eeloo.

[DisarmingBaton5]

This sounds fun. Unfortunately I have only ever built two successful SSTOs, and one of those was all rocket.

[FacticiusVir]

Yeah, I've done a round-trip to Laythe using Ion engines; it's the extra weight of oxidiser & rocket-powered descent that gets me.

[Hodo]

If I wasn't doing another challenge right now I would look at doing this one.

[Sirine]

If I wasn't doing another challenge right now I would look at doing this one.

You may ask 700Nitro to set the 4th mission to Eeloo ...that, you can have 1 stone kill 2 birds.

[Hodo]

You may ask 700Nitro to set the 4th mission to Eeloo ...that, you can have 1 stone kill 2 birds.

I was thinking about the SSTO to Eeloo.

[Sirine]

I was thinking about the SSTO to Eeloo.

Yes, I'm talking about that...put your Core-Craft inside your SSTO. (cargo or just dock with it.)

[Hodo]

Yes, I'm talking about that...put your Core-Craft inside your SSTO. (cargo or just dock with it.)

I don't have a cargo bay wide enough currently, I did, but my mk3 cargo bays don't seem to like career mode. I may have to fix their config file and add them back to the tech tree.

[allmhuran]

Are you allowing gravity slingshots? This would reduce the transfer delta-V requirement down to 2k or less.

[FacticiusVir]

And in a comedy twist, I made it to the Mün and back after all. Still curious to see if/how it scales up to interplanetary.

[tavert]

Stochasty did this in stock a few months back: http://forum.kerbalspaceprogram.com/showthread.php/11214-The-K-Prize-100-reusable-spaceplane-to-orbit-and-back?p=585643&viewfull=1#post585643

[Danish_Savage]

Use a light plane and Ion engines

[Pds314]

Are you allowing gravity slingshots? This would reduce the transfer delta-V requirement down to 2k or less.

Yes, gravity slingshots are allowed. you will still need to figure out the landing though.

Also, the transfer burn on the way there can get as low as 1887 m/s anyway if you wait until Year 13, day 219 at 9:07:12 (hint, the seconds make no difference, and you can probably be an entire orbit off just fine.). In fact, the whole thing from that date takes just 3,318 m/s if executed precisely. Unlike the Mun or Minmus or Duna or Eve, launch windows for Eeloo vary widely in speed and efficiency, from the next local minimum being 290 all the way to 500+ days and somewhere between 3.3 and 4.2 km/s.

[Pds314]

Stochasty did this in stock a few months back: http://forum.kerbalspaceprogram.com/showthread.php/11214-The-K-Prize-100-reusable-spaceplane-to-orbit-and-back?p=585643&viewfull=1#post585643

Whoa! HOWTHEHECK!

There is no way he should have been able to send a spaceplane to Eeloo with that little fuel.

If he posts it I will ask him about that. I would be very surprised if that thing was 55% rocket fuel after reaching orbit. It didn't look like it.

[Dooz]

Im pretty sure it can be done using solar sails ion engines

[tavert]

Whoa! HOWTHEHECK!

There is no way he should have been able to send a spaceplane to Eeloo with that little fuel.

If he posts it I will ask him about that. I would be very surprised if that thing was 55% rocket fuel after reaching orbit. It didn't look like it.

Looking at the design he took to Eeloo (he also had a later improved version he took to Moho), it has an initial wet mass of 24-25 tons, gets to orbit using less than 2 tons of fuel, and has a dry mass of under 10 tons. Almost 7 km/s dV remaining from LKO. You needs lots of intakes to get to orbit almost entirely on a pair of jets, enough wings to get off the ground, 1 LV-N, and the rest fuel. You'd probably have to double the design if you want to use a proper pod instead of a jumpseat.

[Mesklin]

Or you can fly to Eeloo and back with my plane: http://forum.kerbalspaceprogram.com/threads/11214-The-K-Prize-100-reusable-spaceplane-to-orbit-and-back?p=738996&viewfull=1#post738996

[koshelenkovv]

According to this thread maximum theoretical dV for LV-N barely allows to build Eeloo SSTO wcich is capable of landing and return.

I doubt that anyone (okay, any more than 1-2 people) is able to make it.

Using ions is much more easier (but much more tedious).