Clancy

I would probably say major. Unless you're just using it to make things you could also make with stock, i.e. just using it to keep part-count down.

Rescue Complete! I made a pretty simple attempt. Kind of a minimalist brute force method. No fancy gravity assists, just a chair, an Ion drive, lots of Xe and lots of patience. I launched the whole thing into orbit on a Skipper and two Thumpers with a Poodle on the second stage. The ship itself has a command chair, a probe core, and an Ion Engine with the requisite batteries and solar panels to make it run. It carries enough Xe to make about 46,000m/s. Which was more than enough. Once in orbit I set up a 10 hour (!) Ion burn to go into a retro solar orbit. I start with a Sun Pe of 600,000km (so nothing melts) Then adjust the Ap to intersect Burberry’s orbit. Once back at Ap, burn prograde to set up an intercept on the next pass. Once Burberry is safely in his seat, make another loooong burn to get back to and elliptical prograde orbit, make another sun dive to get back to Kerbin orbit, set up intercept on next pass. I didn’t do any crazy aerobraking except de-orbiting, I had plenty of fuel to slow down using the engine. Finally I detached the chair and dropped Burberry into the atmosphere with a heatshield and a parachute on his back. He landed pretty hard, but he survived, so I’ll take it. After 1.5 years of waiting, 1.5 years in a spacesuit, getting irradiated by the sun, almost roasted to death twice, and landing with a 15 m/s face-plant in the middle of the desert, Burberry Kerman is home safe! The Stats: Total Mass: 57.6t Total Cost: 216,352 Total Dv: ~45,000 m/s Total Time: 3 years, 59 days, 1 hour, 40 minutes P.S. Now I’m kicking myself, if I had left out just a few grams of Xenon, I could have beaten @ManEatingApe‘s cost record!

If I might suggest a new rule: If ISRU is used, fuel recovered does NOT count towards recovered cost. Conveniently, I won't have to alter my score, because I sort of already assumed this rule was in place...

Cool! I'm excited to see it!

It was surprisingly easy to upgrade the probe to carry crew. I added the command pods and the sciencey stuff, then I added a drill and ISRU and removed the extra fuel needed for the return trip. As it turns out, the stuff I added has almost the same mass as the return-fuel, which leaves it with about the same total mass as the original probe. It’s a bit longer, but I could basically use the same lifter with some minor tweaks. It actually ended up using less fuel than the original probe. For bonus points, I took two Kerbals. Mainly because I needed an Engineer to run the drill. The Stats: Moho Probe Lifter 1b: Mass (without cargo): 58.4t Liquid Fuel: 3595 Oxidizer: 1842 Moho Probe 1b: Mass: 16t Liquid Fuel: 1600 Monopropellant: 30 Total Fuel Costs: 4523.6

It happened by accident on the previous run, so on the final run, I left out some Oxidizer and made it part of the plan.

Ok, here’s my entry for the Basic level. It’s very basic, an OCTO2 and a battery to Moho and back with a NERV engine. The whole thing is lifted into orbit by a drone piloted spaceplane. I didn’t do any kind of gravity assist maneuvers, but I searched the launch window planner for the cheapest windows in the first ten years. The probe leaves some extra fuel in Moho orbit while it lands, then grabs the tanks back in orbit before leaving orbit. Returning to Kerbin, the probe rendezvous with the plane, which has been in orbit this whole time. The probe is loaded onto the plane, which de-orbits and lands at KSC. All parts launched are recovered at the runway, so the only costs are fuel costs. The Stats: Moho Probe Lifter 1b: Mass (without cargo): 57t Liquid Fuel: 3595 Oxidizer: 1842 Moho Probe 1b: Mass: 16t Liquid Fuel: 2200 Monopropellant: 24 Total Fuel Costs: 4996.36 It could be even more efficient if I spent some time finding gravity assists, and did some really efficient piloting. If I have some time next week, I may try and adapt this method to the advanced category.

Wow. That's pretty efficient! I might try and scale up the NERV design sometime soon, but 88.46 is gonna be hard to beat. I'm gonna finish my entry for the Moho Challenge first.

I’m not sure where this fits in the proposed scoring system, but here’s my entry for category 3: Lifter 2a Payload Mass: 11.6t Lifter Total Mass at Takeoff: 32.22t Lifter Mass Empty: 11.82t Liquid Fuel: 1500 Oxidizer: 660 Fuel Cost: 1318.8 Cost per Ton: 113.7 Album: http://imgur.com/a/u4O5p Powered by 2 RAPIERs and 1 NERV. Just enough Oxidizer to push through the 30-40km, where the NERV can take its time getting to orbit.

Looks pretty good! i like the repeated use of the Cargo Plane design. I might have a go at the basic mode sometime soon.

I'm not really sure what the price points mean, but I see the benefit of splitting entries by class. I think there should be more heavy classes though. I would propose: 1t, 5t, 10t, 25t, 50t. Choose a payload and see how cheaply you can get it to orbit!

I can't speak for the other entrants, providing the craft files wasn't part of the original challenge, but I can show you mine: Heart of Gold + BFR Fuel HoG + BFR

Re-posting my entry with a few pictures: I tried to stay as close to Musk’s plan as I could. Stick a big ship on top of a big booster. Land and recover booster. The main ship uses most of its fuel getting to orbit, where it waits to be refueled. Meanwhile, the booster is re-used to launch another ship which is filled with extra fuel. The refuelling ship docks with the main ship to give it enough fuel to get to Mars (or in this case, Duna) Then the refueller lands back at the Space Center. Now the main ship rockets off to Mars (Duna) (at the appropriate launch window) and Aerobrakes and lands on the surface. Fuel and Oxidizer are mined and processed from the planet’s surface. When the tanks are full again, (and the launch window rolls around) the ship lifts off and heads home. It Aerobrakes at Earth (Kerbin) I gave myself additional restrictions to follow Musk’s plan: No parachutes, No wheels, Everything lands tail-first, Chemical rockets only. The refuelling ship had the same form and same mass as the Main Ship like Musk envisioned to save on engineering and parts (not that those savings show up in KSP) It also meant the booster took the same ascent profile, so I didn’t have to move the drone ship between launches. Here’s the summary: Drone Ship: 89,445 Funds Mass (Empty): 185.3t Liquid Fuel: 2,160 Fuel Cost: 1,728 Funds Launch 1: Heart of Gold + BFR HoG Empty: 316,465 Funds Mass (Empty): 78.5t Liquid Fuel/Oxidizer: 7,245/8,855 Fuel Cost: 7,390 Funds Fuel Mass: 80.5t BFR Empty: 177,327 Funds Mass (Empty): 58.8t Liquid Fuel/Oxidizer: 15,300/18,700 Fuel Cost: 15,606 Funds Fuel Mass: 170.0t Launch 2: Fuel HoG + BFR Fuel HoG Empty: 100,103 Funds Mass (Empty): 41.2t Liquid Fuel/Oxidizer: 10,620/12,980 Fuel Cost: 10,832 Funds Fuel Mass: 118.0t BFR Empty: 177,327 Funds Mass (Empty): 58.8t Liquid Fuel/Oxidizer: 15,300/18,700 Fuel Cost: 15,606 Funds Fuel Mass: 170.0t Total Fuel Costs: 51,162 -1000 for Fuel Recovered +2000 for Landing Legs Replaced on BFR 52,162 Funds Price Tag: 522 Funds/Kerbal

This is a continuation/expansion of a Challenge posted a while back by @jasonden reacting to Elon Musk’s scheme to launch 100 passengers to Mars and return to Earth in a reusable spacecraft. The original is here: http://forum.kerbalspaceprogram.com/index.php?/topic/148926-the-elons-problem-challenge/&page=1 The goal is simple: Take 100 Kerbals (or more) to Duna and return them safely to Kerbin in a reusable (or mostly reusable) spacecraft. The Rules Are: No Cheating (Debug menu, Hyper-edit, Hacking the save file, any “cheaty” mods, etc.) Informational and control mods are OK. Purely visual mods are OK. Entries using modded parts will be scored separately. (Unless the difference is really small) Kerbals must be in pressurized containers, at least during atmospheric flight and interplanetary travel. Scoring is based on cost per Kerbal, which is: Fuel Cost + Cost of any parts launched but not recovered on land* One Craft To Duna. Multiple Launches are OK, Multiple Landings are OK, but the sections must constitute a single craft for the trip to Duna and the trip Home. Fuel Recovered doesn’t count against cost. ISRU is OK except on Kerbin. (i.e. no launching the ship empty, drilling for fuel, then claiming you have no fuel costs) *As discussed in the original, rockets recovered from the water aren’t really reusable, so to count, it has to land on land. Exceptions include: Landing on a floating platform, some other landing scheme where the rockets are protected and you can tell a good story about why they would be OK For my first attempt I copied Musk’s Plan as closely as I could, but there were other good solutions too! Be creative! I’m getting the scoreboard started by pulling in the entries from the original, but hopefully we can add to it! I also want to open it up to other planets/moons as well, so If anyone wants to have a go, I’ll put up some separate categories: Easy Mode: Mun, Minmus Laythe Mode: Laythe Little Moons: Ike, Gilly, Pol, Bop, Vall Big Rocks: Moho, Dres, Eeloo Bigger Rock: Tylo Expert Mode: Eve** **Before I get too many replies saying “You Maniac!” Yes, I realize it is quite impossible (or at least wildly impractical) to have a reusable ship to Eve and back. But therein lies the challenge! Sure, you’ll need some monstrous beast that sheds most of its stages to get to orbit, but how cheap can you make those parts you leave behind? I don’t know, let’s see if anyone can do it at all first. Score Board: Duna - Stock: 462: NoobTool --- 150 Kerbals. Single Launch in a fully reusable Spaceplane 532: Clancy --- Followed Musk’s Plan, No wheels, No Parachutes. Landed Booster on floating platform, refueled with 2nd Launch. Lots of careful aerobraking 1640: Thomas H. --- One launch, SSTO booster, Minmus refuel, careful atmospheric entries to avoid needing heat shields 2240: burner_nn --- Many distributed launches, modular design, link up in LKO for Duna transfer, modules separate again for Duna/Kerbin EDL --- I’ll add and update the score boards as more entries come in. Happy travels!

This is my problem as well. For some reason when you target a stationary object, relative velocity defaults to ORBITAL instead of SURFACE. I sent a couple of landers tumbling across the plains of Minmus and had a few planes stall out as they approach the runway when speed read 200m/s before I figured this out. Now I check the navball mode obsessively during every landing, but that's a work-around, not an ideal solution.

Anyone seen @Jasonden ? It's been over a month. This seemed like a fun challenge, I'd hate to see it end with such a whimper. I was even wondering if anyone would be interested in expanding it to other planets?

I thought at first this might be possible with a small capsule sitting on top of a few Kickbacks ganged together and pointed with the fiery end up. You would have to turn on indestructible parts and no heat damage of course, but maybe it could be done? Then I did some calculations: Assume small capsule includes Mk1 Command Pod, Spark Engine with enough fuel to circularize, parachute, nose cone, heat shield etc. That's like 2.5t. I'm not sure how the thrust pressure of the boosters falls off over distance, but let's assume that it falls off linearly from the max thrust (590kN for Kickbacks) to zero at 25m away. (chime in anyone who knows the real values) That gives F(x)=F0(1-x/25) since a=F/m a(x)=F0/m(1-x/25) Blahblahblah-algebra-calculus-spreadsheets means you would need a base thrust of 400,000kN or 678 Kickbacks together. So, not very practical. I'd still like to see what happens if you hacked the Booster to increase the thrust until it worked. You could also probably use a fairing and a command seat to make a lighter pod. Or a probe core I suppose.

Ok, mission finally complete! Here’s my entry: I tried to stay as close to Musk’s plan as I could. Stick a big ship on top of a big booster. Land and recover booster. The main ship uses most of its fuel getting to orbit, where it waits to be refueled. Meanwhile, the booster is re-used to launch another ship which is filled with extra fuel. The refuelling ship docks with the main ship to give it enough fuel to get to Mars (or in this case, Duna) Then the refueller lands back at the Space Center. Now the main ship rockets off to Mars (Duna) (at the appropriate launch window) and Aerobrakes and lands on the surface. Fuel and Oxidizer are mined and processed from the planet’s surface. When the tanks are full again, (and the launch window rolls around) the ship lifts off and heads home. It Aerobrakes at Earth (Kerbin) I gave myself additional restrictions to follow Musk’s plan: No parachutes, No wheels, Everything lands tail-first, Chemical rockets only. The refuelling ship had the same form and same mass as the Main Ship like Musk envisioned to save on engineering and parts (not that those savings show up in KSP) It also meant the booster took the same ascent profile, so I didn’t have to move the drone ship between launches. Here’s Phase 1: http://imgur.com/a/DijMm And Phase 2: http://imgur.com/a/ZzmpF Here’s the summary: Drone Ship: 89,445 Funds Mass (Empty): 185.3t Liquid Fuel: 2,160 Fuel Cost: 1,728 Funds Launch 1: Heart of Gold + BFR HoG Empty: 316,465 Funds Mass (Empty): 78.5t Liquid Fuel/Oxidizer: 7,245/8,855 Fuel Cost: 7,390 Funds Fuel Mass: 80.5t BFR Empty: 177,327 Funds Mass (Empty): 58.8t Liquid Fuel/Oxidizer: 15,300/18,700 Fuel Cost: 15,606 Funds Fuel Mass: 170.0t Launch 2: Fuel HoG + BFR Fuel HoG Empty: 100,103 Funds Mass (Empty): 41.2t Liquid Fuel/Oxidizer: 10,620/12,980 Fuel Cost: 10,832 Funds Fuel Mass: 118.0t BFR Empty: 177,327 Funds Mass (Empty): 58.8t Liquid Fuel/Oxidizer: 15,300/18,700 Fuel Cost: 15,606 Funds Fuel Mass: 170.0t Total Fuel Costs: 51,162 -1000 for Fuel Recovered +2000 for Landing Legs Replaced on BFR 52,162 Funds Price Tag: 522 Funds/Kerbal

I've got a design that's tested and should work, but I've been out of town and haven't had time to actually fly the mission. Hopefully, I'll have some time this weekend. Here's a preview: http://imgur.com/a/9FotV

I agree that tying the experiment to data transmitted would be awkward and difficult at best. You could have it cross it off the checklist as soon as each experiment is processed in the lab, but I'm not sure that you would really want that. Then how would you know if the experiment still had value when you return it to KSC? Personally, what I want is a better way to know if experiments have been processed in a given lab or not. So, if I just landed on the Mun's East Crater and done a bunch of science, I can look in R&D to see how much Science they would be worth if I carted them back to Kerbin, but I can't know whether any of my various bases and stations have processed that data until I bring it there

The game does keep track though, because you can't process the same experiment in the same lab twice, so it must be keeping a record somewhere of what experiments have been processed in what lab. The problem is that there would then be multiple checklists: One for R&D and one for each Mobile Lab currently in the game. It would be nice to know what experiments would be worth gathering, but it would also get unreasonably complex once you have several labs all over the system. The R&D archives are hard enough to navigate as it is.

Something I discovered after trying to keep an Orbital Mun Station supplied by mining the Mun: It's significantly more efficient to fly to a Minmus surface base and back to the Mun than it is to Land on the Mun. Assuming time is not a factor.

"We choose to put a Ginormous Fuel Tank on the Mun, not because it is easy, but because it is HAAHD!!"

Could we land on a floating platform to recover the booster?

Yes. More generally anything controllable from right-click menus should be available to the action groups.