jinnantonix

Here is my design so far, showing main craft and the last stages of the Eve Ascent Vehicle, which uses a Mainsail and two Reliants /drop tanks. Using MechJeb now for the Eve ascent - very helpful. Also having the Terrier in line (reversed) with the main craft and with an ISP=345 helps with those tight transfers where maximum fuel efficiency is needed (although extreme patience is called for). The solution is passing all the tests, I even have a chute for landing on Kerbin! I expect to do the mission and video soon. Only question is whether I need to refuel at Gilly to have enough fuel for the powered landing on Eve.

Yes, but would Matt Lowne be impressed? Considering there is no SSTO involved, perhaps not.

LOL, I so totally misundertood. Thanks for clarifying. I am relieved, if I don't need to carry the ore from Kerbin to Eve , this means my current design is now pretty close to completion. Just need to figure out how to land on Eve without heat shields. It needs a lot of fuel to decelerate from orbit to 1500m/s. Currently thinking it might be necessary to refuel on Gilly prior to Eve descent.

RIghto, that's exactly what I thought you meant. So basically you must launch with 30t of ore, and land of Minmus with 30t of ore. Got it. So how do you know that an entry has met with that criteria based on the screenshots?

Well, I enjoyed this challenge so much, I am going to do it again. Next time I will really trim down the craft to be super cheap. It may be a few weeks before I complete though, I am very busy at work.

@Laie , at the risk sounding like I am nitpicking, I think including the transfer detail is very important for this challenge for a number of reasons. It's true that designing a low cost Eve Ascent Vehicle is the hardest part by far (hats off to @ManEatingApe for that extraordinary effort). The next part is the EAV surviving Eve entry. You need to carry heavy heat shields, or enough fuel after the Kerbin-Eve transit to decelerate to 1500m/s as ManEatingApe did, even with repeated aero-braking at Eve you need fuel in the tanks for that final entry. The crew return vehicle (BTW, you actually did say something about getting the crew back, I checked ... twice) , this adds weight which consumes fuel during the Kerbin-Eve transit, so maybe need to add some drop tanks. I had considered using command chairs for the RV, but I interpreted your requirement here as needing pods for the Kerbin re-entry, can you clarify?) Anyway, the RV increases the craft total weight, so need to add fuel/engines for the Kerbin launch and Kerbin-Minmus transit. It all adds up. My EAV was just under $600k including ISRU, heat shields, fully fuelled etc, but when you add the RV and the Kerbin launch boosters it adds >50% to the total cost on the launchpad.

I have a solution to this challenge, in super hard mode (delivery 60 tons in less than 3 years). The craft is three stage, comprising (1) a fully re-usable "Superlifter" from KSC, (2) an interplanetary tug and (3) a manned Laythe lander with 4 x 15 ton drop ore containers. The hybrid lander/tug delivery craft launches on the SuperLifter which stays in Kerbin orbit for the delivery craft to return. The delivery craft transits Kerbin to Laythe orbit. The craft's lander undocks with the tug, lands on Laythe, refuels, drops ore, and returns to orbit. The tug refuels at Vall and returns to Laythe docking with the lander. The delivery craft then returns to Kerbin (via Pol refuelling stop), docks with the SuperLifter, and lands intact at the KSC for full recovery. Only consumables for the journey are fuel, chutes and heat shields, (no drop tanks). Other notes: All stock parts, manually piloted, no mods ISRU uses RTG and fuel cell only – no solar. Will work on all planets, including Eeloo. Heat dissipation designed to work on Moho and Eve 2 x engineers required, pilot used for launch and Kerbin re-entry, but is optional Hitchhiker included for maximum crew comfort For <3 year (rapid) transit, added heat shields and launch boosters. Not required for 4 year transit

Mission was completed as follows: All stock parts, vessel cost = $973,120 Engines used: Stage 1 (Kerbin Launch): 2 x Mammoth Stage 2 (Eve Launch): 4 x Mammoth + 8x Twin Boar + 8 x Vector Stage 3 (Eve Orbit): 8x Vector (reused) + 8x Terrier Stage 4 (Return): 8x Terrier (reused) + 2 x Twitch No mods used in the mission. HyperEdit and MechJeb were used during testing. Crew : Bill Kerman (engineer) for EAV (Eve Ascent Vehicle) with mining rig, and Val Kerman (pilot) for rendezvous of RV (Return Vehicle) with EAV/ore in Eve orbit. No antennas used. Landing site on Eve, altitude = 162m. EAV was tested successfully at sea level The most interesting part of the mission was the Eve orbital strategy. It was important to complete the orbit in the same direction and plane as Gilly. This required the craft approach Eve, decelerate to just within Eve SOI, warp up to Ap, burn retrograde to zero speed relative to Eve, then burn prograde into an orbit in the same plane as Gilly and Pe ~78km altitude for aerobraking. There was enough fuel to circularise the orbit after only just one aerobrake manoeuvre. After entering low Eve orbit, the RV (return vehicle) separated ready to burn straight to Gilly without any wasteful normal burn. When the EAV/ore reached orbit it was slightly out of plane, but had just enough fuel to adjust and align in the same plane as the RV and Gilly. The return vehicle then manoeuvred within the plane to rendezvous and dock with the EAV/ore. By far the most challenging part of this project was building a low cost EAV that made low Eve orbit with enough fuel to rendezvous with the RV, and was in a configuration that was stable during descent so landed safely and reliably – I think this is a problem with some of the other ascent vehicle designs posted here. The heat shield configuration (4 at top and 4 at bottom) required a lot of R&D, especially working out how to eject the shields without the craft exploding. The key was using just the right number of chutes to slow the craft for decoupling the lower shields, and using an engine burn to get clear. I am certain that it is possible to do this mission at a lower cost. I already have a few ideas on how to build a cheaper EAV. Also the RV was a bit over-designed, had excess fuel, I didn’t even need any aerobraking to decelerate to low Kerbin orbit. Looking forward to seeing other entries.

I have successfully completed the Eve Ascent Vehicle, capable of launch from sea level, and tested all key aspects of the mission. The EAV just needed a bit of patient R&D work, choosing the right combinations of LFBs and Mammoth engines. I am sure I can make this cheaper by trimming back on the finer points, but its good enough for a start. Mission is underway. Mission Update: Successfully refuelled on Minmus and transited to Eve. Orbiting Eve now aligned with Gilly, Return craft is separated, and ready to land the EAV. Just need to find a site with ore at <300m altitude. I just realised that I accidentally forgot to jettison 538 units of excess ore on Minmus. I still easily made Eve orbit with fuel to spare by using aero-braking. Update 2: EAV landing and refuel, launch , rendezvous and Gilly ore delivery complete. Currently in high Eve orbit waiting on window to Kerbin transit. Update 3: Mission completed, see below. Final craft <$1M funds.

I thought I was close to doing this mission, but then discovered problems with my Eve ascent vehicle. Big difference between launching from 500m and launching from 10m. From sea level I am still a 300dV short of getting to orbit. I keep adding engines and fuel, and success is no closer. I no longer care about the mission cost. Just completing the mission will be an achievement.

@AeroboiI had considered using terriers for the for the return, and since you mention it, you are right they are way cheaper. I will put some thought into that idea, thanks.

@Aeroboi your Eve Ascent vehicle looks very compact. I did a lot of testing, and could not reduce the size and cost the way you have. I am not using Making History parts, and used a combination of twin boar and vectors. I don't know too much about Wolfhound, but it sounds like it may be giving your design an substantial edge. Also, if you haven't tested the transport of the ore from Eve to Gilly, suggest you look into that. It requires a considerable amount of fuel. I used a multistage craft using 4 x LN-V engines and drop tanks. Even with the tanks empty on Kerbin launch, the craft weight and cost that this adds to the launch Minmus transit are not insignificant.

OK, here is my crazy rocket for this crazy challenge. Making an Eve ascent vehicle for low cost was hard enough, then figuring out how to land it in one piece, and getting to Kerbin orbit added a lot of cost. Just over $1M in funds for this puppy. Still got one or two tests to go, but expect to have the mission completed in a few days.

@DBowman very clever use of orbital mechanics to reduce fuel usage. Also liked your idea of re-using the franken capsule Duna Ascent vehicle for Kerbin re-entry. Although not sure Werner would have landed it on Duna upside down

I am thinking of a mission to put a 3 man base on each moon, with hitchhiker, ISRU, science lab and equipment. Mission includes delivering all 15 Kerbals, and returning them to Kerbin in a single mission.

I would be interested in trying a colony approach to Jool-5, and complete at Jebediah level. What constitutes a colony? Does it require adding a life support mod? If so which one is best?

A Gilly Hopper doesn't really need a lot of thought. I am planning to collect all the Gilly science with the interplanetary transfer stage. It has ISRU, so I can fly around Gilly all I like, and then refuel for the trip home. The only real challenge with Gilly is landing a big heavy craft in near zero gravity. Takes patience.

OK, I have my big Eve Explorer Mission underway, aim is to collect as much science as possible from Eve and Gilly in a single mission. So far I have all the fly-by and suborbital science for Eve that I can reasonable collect (it is hard to get it all). I am about 1/3 way through collecting surface and low atmosphere science from 9 biomes. Just about to reach Craters. Hoping to get all 15 biomes, but may not have enough solar panels on my Eve Biome Hopper to get to the Poles. When Eve surface is completed and crew is back in orbit, the mother craft has the facility to collect all orbital and high atmosphere science, and also Gilly. I hope. Update: Big challenge was mountain hopping from Craters to the Western Sea, avoiding the barren Midlands (no ore). Also, the sides of Akatsuki Lake are steep, so needed some careful manual flying to land, float, get science, take off and get back to Highlands to refuel. Now at poles, still plenty of solar power, and making the big haul to Crater Lake down the western side of the Eastern Sea. Two biomes to go! Update 2: 15 biomes completed ! Now bringing down the lander to take my Kerbals back to orbit. Update 3: Lander is down safely, but will need to fly a few more hops to reach it. Update 4: Kerbals in orbit, completed collect most science in space above Eve and Gilly, and refuelled at Gilly for the return to Kerbin. Update 5: Mission completed, video below

Eve is a big challenge, especially for collecting science. . Originally I posted this as a challenge, but due to lack of interest I have removed. Happy to put it back up if there is any interest. This thread is now documenting my big Eve Science Mission

I have a jet/boat with ISRU that can do about 70km range. Typically I fly at 55km/s up to around 5000 m then glide to the surface. I have no problems using 4x warp which reduces game time for the flight to only 4 minutes (and MechJeb helps). Warp also works when jetboating at 30m/s on liquid. I was able to do a mission which collected from 6 biomes in a few hours, and I think I can do all 15 biomes with another few hours of game time (~40 hops x 4 minutes), but I am still testing and finding challenges. Kerbolitto, I have tried flying higher and gliding longer and it makes little difference to range or game time. Laie, it is an interesting idea to make a jet/rover hybrid, let us know if that results in a positive outcome. With a combination of Mechjeb and Bon Voyage that may reduce the game time.

Thanks DE, I really enjoyed this challenge. The spinning was intended to provide artificial gravity to the habitat ring. Version is 1.4.5