An Extended Vacation

[MagiMaster]

High Command needs to get Jeb out of the office for a good long while and they might as well get some Science! done in the process so they've decided to send him to both Moho and Eeloo in one mission. However, they'll be in serious trouble if he doesn't return eventually.

This is more of a did-it-or-not kind of challenge, but in the spirit of competition here are some sub-missions each worth one . Ties will be broken by total mass launched (lower is better) since High Command doesn't want to waste more money that necessary on this, so make sure to get screenshots of your launch mass, along with enough shots to demonstrate your accomplishments.

- Complete the mission. That is, land one kerbal (Jeb would be appropriate) on both Eeloo and Moho. Then return all kerbals launched, including kerbals launched for sub-missions, safely to Kerbin's surface. Anything else goes unless you're going for some of the other achievements. (All valid entries must complete this achievement.)

- Make all landings with the same lander. This means the lander cannot be staged until after the last landing.

- During the mission, fly by at least two different planets (other than Kerbin, Moho and Eeloo). No need to do more than enter their SoI.

- Rendezvous with another ship somewhere outside of Kerbin's SoI to change out at least two crew members. At least one of the original kerbals must remain with the original ship. All kerbals must eventually be returned safely to Kerbin's surface. (This does mean your ship must carry at least 3 kerbals.)

- Do the entire mission with no orbital construction. You can dock for refueling or crew transfer if you separate before making significant maneuvers. Parts already docked to the ship during the initial launch don't count, so you can dock and undock your lander freely.

- Land at least 5 kerbals on each landing. Strictly speaking, these don't have to be the same 5 kerbals. All kerbals launched must be returned alive to the surface of Kerbin for it to be a valid entry.

- Land on a third body outside of the Kerbin SoI. That is, land somewhere besides Moho, Eeloo, Kerbin, Mun or Minmus. To get this and the lander reuse achievement, you must use the same lander for all three landings. To get this and the 5 kerbals achievement, you must land 5 kerbals in all three landings.

Some seeming necessary legalese:

- No cheating. No debug menu. No magic parts. No HyperEdit.

- Mods are fine as long as they don't provide parts that are strictly superior to stock parts. That is, if you could replace X stock parts with Y mod parts and gain something with no significant trade offs, those mod parts cannot be used. Information only mods are fine. Autopilot mods are fine (though kudos if your ships could be flown without them). In any case, please mention what mods you used.

- I reserve the right to amend these rules if I've overlooked any loopholes that make the challenge significantly easier than intended. The amended rules may reduce or invalidate the entry that prompted the amendment, but I will try not to reduce or invalidate any preexisting entries in the process. Also, I don't want to have to define things like "lander" but I will if it becomes an issue.

- I reserve the right to add more if someone does something significantly awesome and I can generalize that to fit with the rest of the . New will be awarded retroactively if there's enough evidence to do so.

- I reserve the right to interpret "significant" and "significantly".

I have checked that this is at least theoretically possible. A straight flight from Kerbin to Eeloo to Moho to Kerbin would take about 17-22 km/s dV, plus about 5 km/s for launch and less than another 4 km/s for the lander. This falls below the record for the Delta-V Maximization Challenge. Besides that, in-flight refueling and gravity assists can reduce the dV required to doable levels.

I have a flight plan and some ships mostly built that can make the trip and should get all the if I can keep them intact during launch. It might still be a while before I manage to submit my own entry (which is surely not optimal at roughly 4 kilotons to be launched), but I wanted to go ahead and post the challenge itself.

Near Stock Leaderboard (info, autopilot and difficulty-increasing mods and parts with stock-level performance)

1. - :cool: :cool: :cool: Hakari - 1040 tons
   
2. - :cool: :cool: :cool: Alchemist - 1580 tons
   
3. - :cool: :cool: Jasonden - 684 tons
   
4. - :cool: :cool: Kasuha - 1653 tons
   
5. - :cool: Mobjack - 487 tons
   
6. -
   
7. -
   
8. -
   

Major Mods Leaderboard (all other non-magic parts and mods)

1. - :cool: :cool: Hakari - 220 tons (Near Future Pack)
   
2. - :cool: :cool: chlue - 496 tons (Near Future Pack)
   
3. -
   
4. -
   

Entries using these mods go on the modded leaderboard. This is not a comprehensive list and will be updated as issues arise.

• Near Future Propulsion Pack
  

Edited January 29, 2014 by MagiMaster
Clarification. Leaderboard.

[Sirine]

I reserved the right to say this.

Crazy challenge.

Have you ever attempt this?

[Kingtj44]

Wow...that is rather "difficult". Is that the right word? Not sure.

[MagiMaster]

I am currently attempting it. I have a vessel that can do everything required, but while I can get it into orbit, I still need to get a slightly heavier second ship into orbit too. (If I abandoned the no orbital construction sub-mission...) Actually flying the mission will take a little while, but hopefully shouldn't present any huge, unforeseen difficulties (fingers crossed).

[SkyRender]

As long as you don't mind it taking a while, you can get from Kerbin to Moho for quite a lot less dV than going there directly by way of a pair of Eve gravity slingshots. (I did say it would take a while...) Similarly, you can skip up from Moho to Eeloo for relatively little by using Eve, Kerbin, and Jool as slingshots. I cringe to think of how high the total mission time would be for such a fuel-efficient means, though; probably in the range of 50+ years.

[Epthelyn]

As long as you don't mind it taking a while, you can get from Kerbin to Moho for quite a lot less dV than going there directly by way of a pair of Eve gravity slingshots. (I did say it would take a while...) Similarly, you can skip up from Moho to Eeloo for relatively little by using Eve, Kerbin, and Jool as slingshots. I cringe to think of how high the total mission time would be for such a fuel-efficient means, though; probably in the range of 50+ years.

It could work at half efficiency:

1) Standard transfer from Kerbin to Moho

2) Circularise and land on Moho

3) Leave Moho

4) Use Eve as a single gravity assist to reach an apoapsis level with Eeloo's orbit

5) Circularise, or capture

If Eeloo was roughly in the right place when doing the Eve assist it would only take a few years, probably less than 10; the advantage of being on Moho first is that it moves far faster than the other planets and so you can probably get the maneuver set up and carried out in a far shorter time than doing Kerbin -> Eeloo -> Moho.

Getting back to Kerbin from either is pretty easy in comparison, probably making use of Duna's atmosphere to slow down before going as low down as Kerbin's orbit.

So Kerbin -> Moho -> Eve (flyby assist) -> Eeloo -> Duna (flyby(/assist)) -> Kerbin

Could be an interesting trip

The restriction on orbital construction is pretty harsh though, considering how difficult this is already, but that's just for extra credit

EDIT:

Progress Report:

Launched from Kerbin, forgot to fill the hitchhiker compartment required for one of the sub-missions and so had to rendezvous to transfer 4 Kerbals over, accidentally getting a sub-mission completed (only took 3 months in orbit to catch up)

Currently heading out towards Moho with a TWR in Kerbol orbit of 0.188. 48 minute burn

I may have to refuel somehow after Moho, because I think the dV display for the rocket in the VAB (on Engineer) was displaying lander dV if the nuclear engine was burning that fuel. Oh well. Definitely have enough for Moho at any rate.

Oh, and I have no idea where Jeb is, so I have Thompfat instead

Edited January 18, 2014 by Epthelyn

[Hakari]

I'm gonna try this with the Near future propusion pack. Cuz otherwise it would require either extreme command chair only mass saving, or gigantic ships that are a pain in the ass to launch.

Edited January 18, 2014 by Hakari

[SkyRender]

So I did some calculations with the launch window planner and discovered that you can run this whole mission in around 3.5 years... assuming that you can somehow build a ship with a cumulative 18,600dV or so (13,600 for transfers, 5000dV for landings).

Where's Whackjob when you need him?

[chlue]

Ok quiet sure it is not in the spirit of this challenge, but I have to ask

Since you already allow refueling and docking, do you allow kethane based fuel mining too? I guess this would reduce the delta-v need to <10k starting from Kerbin orbit.

[Mobjack]

Did it.

I was just testing out if this was feasible, hence the name ship Moho Test, but was able to complete the whole mission.

Total Rocket Delta-V was about 18,338 m/s from Kerbal Engineer, but it was probably more as I refueled my lander twice from my main fuel tank. I used two gravity assists from Eve which helped significantly getting from Moho to Eeloo.

Mass was 487,000 KG.

Total time was 6 years and 147 days.

Mods were Alarm Clock and Kerbal Engineer Redux.

One tip is to ignore the transfer windows from the calculators. Instead of going for a direct approach, focus on matching your orbit with the planet's orbit as efficiently as possible, then adjust to make an encounter. Eeloo and Moho have eccentric orbits so it makes the transfer window guides unreliable.

I wish I took more pictures of my maneuvers, but my strategy was this:

1. Do a transfer to reach Moho's periapsis. I didn't care where the Moho was.

2. When reaching the periapsis, slow down until you create an encounter.

3. Land on Moho.

4. Waited for a 159 days for a good transfer opportunity to Eve.

5. Did two gravity assists with Eve until my apoapsis went out to Eeloo's orbit.

6. Adjust my orbit to create an encounter Eeloo.

7. Wait over 3 years before finally reaching Eeloo.

8. Waited for a transfer window to Kerbin then went home.

Upon returning, I realized I didn't have a parachute, so I parked with a space station around Kerbin. I hope this counts as returning as this took much more dV than landing. My Kerbal got to meet with his friends and has an escape capsule if he really needs to go home.

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Edited January 19, 2014 by Mobjack

[MagiMaster]

@Mobjack, Very nice. I've only just managed to get everything into orbit (and not without some mechanical assistance), although you reminded me that I forgot a return system too. I'll count docking at a space station as that is very similar to several other definitely valid ways of returning your kerbals (such as sending up a crew shuttle).

Let's see. It looks like you got the reuse the same lander and the no orbital construction achievements. Two Eve flybys doesn't quite get the flyby two planets achievement though. (I should make that a little clearer in the rules.)

@chlue, I'll have to think about that. It's a neat idea, but I might have to say no, at least not on the main leaderboard. It seems like it'd be too big of an advantage, but you might could convince me otherwise. (Anyone that finishes the mission at all will at least get an honorable mention though, and if there's enough interest, I can make a separate leaderboard.)

On the other hand, docking at a Kethane factory wouldn't be hugely different than docking at any other refueling station. Anyone else have any thoughts on this?

[Hakari]

My kerbals came back after 4 years in space. Even with a VASMIR plasma thruster which gave me something like 30k+ dv I barely made it. I might be able to save about 1/3 of that through optimal gravity assist but that's still very difficult to achieve with just NTRs. Main difficulty being the complete pain in the ass that is plotting optimal orbits without a team of physicists helping me out, most of the stuff provided by MechJeb or Protractor don't work with low TWR crafts so you really just have to eye ball a lot of these things, which needless to say, is not very efficient or optimal. Also when dealing with far out planets like Eeloo, floating point precision kicks in and orbits start to shake around, on top of bad and stupid camera angles, just so frustrating.

Even had to replace my lander at Moho with Hyperedit because for some reason the fuel lines weren't properly connected and I couldn't start the lander engine.

Did no rendezvous with another craft because I don't have any out there, it's a pointless challenge really since you could just send out another probe beforehand to one of the destinations, simple time grind.

Aero breaking at duna, and gravity sling by Eve to further reduce orbit on the way back to Kerbin.

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Edited January 19, 2014 by Hakari

[MagiMaster]

So you got the 5 kerbals, reused lander, flyby 2 extra planets and no orbital construction achievements, right? I suppose I'll let the use of HyperEdit slide if all you did was put back the missing fuel lines. No pictures, but I trust everyone made it back to the ground safely.

BTW, the rendezvous gives you a chance to refuel, but to get that achievement, you can't just fly to Moho, come back to Kerbin and refuel and then fly to Eeloo as two practically separate missions. But I didn't specify that you have to refuel during the rendezvous to keep things open. I was considering adding another for swapping crew out mid-mission, but I'm not entirely certain it'd be possible to do all six at once.

I'm debating whether I should say "don't return to Kerbin SoI mid-flight" or making that a bonus... I feel like I should do one of the two because the existing rules don't really prevent getting all 5 achievements while basically flying the whole thing as two separate missions...

Edited January 19, 2014 by MagiMaster

[MagiMaster]

Mobjack, I just realized that while docking at a space station is fine, I should add the weight of a crew return vehicle to your score. For your 1 kerbal, that shouldn't be too much, but do you have any such craft already built you could weight?

[Hakari]

Actually I didn't land safely because for some reason the game crashes before the capsule reached ground, I tried twice and they both crashed at about the same altitude.

I did have about 800 m/s in that lander so if the game didn't crash I should have more than enough to land.

The lander fuel line you could see in one of the screen shots, were not connected to the engine when I undocked it at Moho.

[Epthelyn]

Re-doing my attempt because this happened:

Considering I would've ended up having to refuel twice (once at (maybe) Eve and once somewhere between Eeloo and Kerbin) it's not a major disadvantage.

Reworked vehicle is going to be built in orbit and I think should have enough dV to get to Moho and then up to Eeloo before needing to rendezvous for fuel. Might be able to leave 2 of the 3 LV-Ns around Eeloo and use a single one to get back to Kerbin, adding enough to do it all without refuelling

Unfortunately that plan misses out two or three of the :cool:s that I wanted to get

[Mobjack]

I would argue that the Near Future Pack goes against the "Mods are fine as long as they don't provide parts that are strictly superior to stock parts" rule.

My suggestion is to have a separate leader board for stock and modded parts. Keep a list of what mods are acceptable in each category so it is clear up front.

I agree with Hakari that the docking with another ship achievement is kind of pointless. For me, if you can do the whole trip with one launch without docking to refuel, then it should be an achievement on its own.

Which brings me to this rule:

- Do the entire mission with no orbital construction. You can dock for refueling or crew transfer if you separate before making significant maneuvers. Landers don't count as long as they aren't providing a significant portion of the orbital/interplanetary dV.

Docking to refuel and orbital construction provide similar advantages. Instead of docking in Kerbin orbit, just send the fuel tanks to orbit Moho and Eeloo ahead of time. With the extra points for docking outside Kerbin's SOI, this strategy is overpowered.

I would simplify the rule, saying that orbital construction and refueling are permitted, but you can get bonus points for doing it all in one launch.

Maybe this would work:

For doing the challenge with refueling.

:cool: For doing it with one launch.

Also be more clear on what are the minimum requirements for completing this mission and give it one . I can't tell if orbital construction is even permitted for example.

Then specify the additional bonuses separately.

[MagiMaster]

It's quite a bit of effort to send a full fuel tank to either Eeloo or Moho especially if you can't construct the refueler in orbit either. And orbital construction makes things much easier because of the initial 4.5-5 km/s needed to get it all off Kerbin. My design needs about 3 orange tanks to make half the trip, stopping at Eve to refuel, which means the refueling ship needs 4 orange tanks. If I could launch those in pairs, I could probably raise than number and not have to deal with having such low thrust. But I'm willing to be convinced otherwise.

I didn't want to make "all in one launch" an achievement because I wasn't sure it'd be possible without mods. (I guess you've proven it is though.) I'll have to think about it a bit.

BTW, anyone else have any thoughts on the Near Future Pack? 30 km/s on a 200 ton launch does seem pretty superior to stock.

I'll go ahead and add a "mission complete" achievement either way.

Edited January 19, 2014 by MagiMaster

[Hakari]

It's quite a bit of effort to send a full fuel tank to either Eeloo or Moho especially if you can't construct the refueler in orbit either. And orbital construction makes things much easier because of the initial 4.5-5 km/s needed to get it all off Kerbin. My design needs about 3 orange tanks to make half the trip, stopping at Eve to refuel, which means the refueling ship needs 4 orange tanks. If I could launch those in pairs, I could probably raise than number and not have to deal with having such low thrust. But I'm willing to be convinced otherwise.

I didn't want to make "all in one launch" an achievement because I wasn't sure it'd be possible without mods. (I guess you've proven it is though.) I'll have to think about it a bit.

BTW, anyone else have any thoughts on the Near Future Pack? 30 km/s on a 200 ton launch does seem pretty superior to stock.

I'll go ahead and add a "mission complete" achievement either way.

the VASMIR is quite simply a superior ion thruster with higher ISP and higher thrust, like all the other thrusters in the near future pack.

I think it would be possible to do the same with ion thrusters, you just have to deal with lower thrust and more solar panel pointing.

I am also working on a stock performance run.

Edited January 19, 2014 by Hakari

[MagiMaster]

Would an ion ship still weight about the same if you built it to the same thrust and dV?

I went ahead and made a separate leaderboard either way, but we can work out which category the Near Future Pack should fall under.

I also made another pass over the achievements. I added one for "complete the mission" which yall both already got, I specified that you can't return Jeb to the Kerbin SoI (not just the surface) and I changed to rendezvous to a crew swap. It'll be an actual achievement to pull that off, I think. But I still need to work out what to do about the orbital construction achievement. If I could be sure that it was possible to get all the achievements in a stock run, I'd change it to a no docking rule (as you can do a crew change without docking), but that's a whole lot of dV for one ship and I don't want to force everyone to use ion engines. My ship already needs an hour burn here and there on two nuclear engines.

[Mobjack]

It's quite a bit of effort to send a full fuel tank to either Eeloo or Moho especially if you can't construct the refueler in orbit either. And orbital construction makes things much easier because of the initial 4.5-5 km/s needed to get it all off Kerbin. My design needs about 3 orange tanks to make half the trip, stopping at Eve to refuel, which means the refueling ship needs 4 orange tanks. If I could launch those in pairs, I could probably raise than number and not have to deal with having such low thrust. But I'm willing to be convinced otherwise.

I didn't want to make "all in one launch" an achievement because I wasn't sure it'd be possible without mods. (I guess you've proven it is though.) I'll have to think about it a bit.

It takes the same effort launching a fuel tank to Moho's orbit as it does constructing a ship with a detachable fuel tank then sending it to Moho.

This is achievable in one trip, but you need to work smarter and not harder. The secret is knowing when to time your transfer windows around Moho.

I might try the challenge again with 5 kerbals and will document the individual transfers with more screenshots to show how it is done.

[MagiMaster]

Hmm... I suppose so. You could still send the extra fuel to Eve or Duna instead, but I think "refuel at Eve with no orbital construction" might be easier than "no refueling with orbital construction." I suppose I'll have to rework that achievement. I can't just say do everything in one launch though unless I completely replace the rendezvous achievement. I'm not quite sure how to resolve that...

Edit: Would it work if I said do the mission without docking? You can still rendezvous and transfer crew without docking. (Well, no docking besides the landers. So maybe no docking besides what was pre-docked during the initial launch.)

Edited January 19, 2014 by MagiMaster

[Epthelyn]

Would an ion ship still weight about the same if you built it to the same thrust and dV?

It's not really feasible to get 60kN (for LV-N) of thrust from ion engines. That's 120 of them.

Edited January 19, 2014 by Epthelyn

[MagiMaster]

Maybe, but it'd have several thousand more parts.

If it's basically the same (results-wise) as welded stacks of xenon tanks and banks of ion thrusters, then it'd be fine. I suppose I'll have to look in to it a bit.

[Hakari]

Tried again and got all 6 achievements, with just NTR and chemical rockets.

2x refuel at Moho and Eeloo, 10k dv each, and about 25k dv for all the transfers. Didn't really need a crew transfer but it'll be easier than building a car with huge tall latter or attempt to navigate the inside of the aero shell on EVA. The fuel probes are actually a lot heavier than the craft itself.

430t refuel probe launch

180t main vehicle with lander

32t crew launch

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Edited January 20, 2014 by Hakari