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My first attempt at an Eve Lander. A 1700 ton monstruosity?


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Where exactly in the Rule Book does it say that your capsule has to be at the *top* of the lander?

Make the middle stack of your lander be capsule at ground level, then all the other non-propulsive bits above that. Or attach the can to the side of the central stack, with a suitable counterweight offsetting the balance, or attach the ladder to a chunk that will stay on the ground, or include a lil' 1-kerbal jetpack "rover" on your lander, or...

As down-mass is not very relevant, only your up-mass in the ascent stage needs to be finely optimised.

My (failed) 1700 ton lander had the capsule at the bottom: From top to bottom the centerline fuel tanks had the jumbo fuel tanks, a decoupler with fuel lines connecting it to the tanks, an mk2 lander can with radial parachutes attached and a Skipper engine at the bottom. It also had a science module with monopropellant tanks, parachutes, SAS modules, batteries and a docking port on top.

The reentry procedure to Kerbin (tested during trial runs) required to rotate the ship so the top decoupler would eject the science module away from the rest of the ship and using an action group to key to fire the decoupler and activate the science module parachutes. The kerbanaut would then rotate the ship 180° so the bottom decoupler would eject the MK2 lander can away from the fuel tanks and another action group would fire the bottom decoupler and the lander can parachutes.

And speaking of trial runs "Eve Lander Test 2" was put on test this fine Kerbal afternoon. After considering flight rockeeter sdj64 suggestion, the motto "moar landing struts" was added to the kerbal engineering library, next to "moar struts" and "moar rockets". A suggestion from spacecraft engineer MarvinKitFox to use girder modules to land was rejected on aesthetic grounds - despite objections from part of the team under the argument of "aesthetic, this?". Girders were used nonetheless, to lower the KAS pipe connectors, in preparation for a possible refueling mission when in the ground on Eve.

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The test run succeed in being a non catastrophic failure. The first objective was to try the combination of a SAS module and the final stage engines to control the ship during the gravity turn. It succeed, though the ship had ascended 2,500 meters between the start of the gravity turn and its end. Flight engineers note that the ship was ascending without detaching the empty tanks, so more agility is expected during the Eve take off.

Objective #2 was to achieve low Kerbal orbit without detaching any stage. Should the objective was achieved, no funds for a first stage for Kerbin take off would need to be allocated from the unlimited budget of the Kerbal Space Program and, after a refueling run, the ship would remain in orbit waiting for docking with the interplantary injector and trans-Eve injection during the proper transfer window. Objective #2, however, was a failure. "Eve Lander Test 2" did indeed clear the Kerbal atmosphere. However, it was too slow to turn in the proper direction to raise periapsis and failed to achieve orbit. Controversy remains as to whether it's a design issue or the remote probe operator was too timid in its turn to prevent a tip-off. This is assumed to be non-issue for Eve take off, as the ship is expected to be composed of only the final, more nimble, stage by this point. It does raise questions about it's ability to make it to Kerbal orbit. Questions which will be answered during the first stage design.

After the failure to achieve orbit, engineers then turned to test it's dry landing capabilities. If possible, they wanted to land the ship on solid ground - a test never achieved by this prototype. Again, this failed. Without enough fuel to fly through the atmosphere, mission control resigned themselves to yet another water landing. With fuel tanks dry and additional parachutes (adding a "moar chutes" tome to the Kerbal Library is now under consideration), descend speed was a 7.2 m/s. A short rocket burn cut it to 5 m/s and the prototype did it's first landing without compromising the ship's structural integrity.

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Additional issues still remain. It is believed that kerbonauts no longer think stealing the snacks from the kitchen is enough, but they've also deleted the action groups to decouple the landing gear and parachutes. The issue has been quickly fixed, after a series of heated arguments between engineers and kerbonauts, who accused the engineers of forgetting to reapply the action groups after modifying the vessel (and having lousy snacks). Proponents of the "moar struts" school of engineering have also complained about the lack of struts, citing fuel tanks tilting during take off and the apparent structural risk of holding the upper stage with a single beam. Moar Struts are now expected in the final vessel.

Edited by juanml82
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  • 4 months later...

Well, it may not be polite to bump this, but on the other hand, I also think it's not polite to forget about telling those who participated the results

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It worked! The really complicated part was the landing - this large lander can not land in any slope in Eve and requires flat terrain, otherwise the aerospikes would end up hitting the ground and breaking apart from the ship. MJ landing module didn't cut it for this type of mission. Precise as it is, it also burns fuel and my idea was to land the ship with full tanks so to avoid having to land a tanker to refuel it on the ground. And pinpointing flat terrain from orbit is almost impossible - I've ended up landing in a slope just a few hundred meters away from flat terrain. But I've eventually made it :D and no rocket assistance was required - the chutes were enough to slow down the lander. And Randall Kerbal can fall from the seat right into the ground without killing himself. Which is good, because I can't detach him out of the seat and into the ladders (the opposite does work)

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And taking off was so smooth I was able to end up in a 260 km orbit with spare fuel in my upper stage. An improved version of this lander is heading for Tylo, and I don't think it shouldn't have any problem expect for the slope issue.

Anyway, this ship was done before 0.23.5, so I guess the new parts make Eve manned missions easier. I also think it's best to do science on Eve's surface by also landing a science rover nearby with the heavier science modules, or using a detachable part of the lander, if it can be attached (and later detached) somewhere. Do science on the surface, let the kerbonaut grab all results, pack and leave. Now to wait for the transfer window back to Kerbin and end one of the most complicated mission I've made.

Here's a gallery

http://imgur.com/a/gb57h#0

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Minimize weight as possibly, especially for top stages, no RCS on lander, no decorative only details, no chutes and legs in ascending time. Also you can try to start from mountains, it is decrease dV for ascent and harshly decrease weight (wheeled lander will be good). For example my lander fro my grand tour: lander weight is only 15.7t (128 details) and ascend part from it - 13.6t (102 details). dV in lander 9500 m/s (starting point should be on mountain more then 6000m)

See details in link

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I love seeing everyone's solutions! There are so many different ways to do this, of course.

Personally I felt like the external command-chair was a little cheaty, so I went with a lander-can and a fairly typical "aerospike asparagus" sort of thing. It's probably been mentioned, but the beauty of the toroidal aerospike engine is that it doesn't lose much efficiency in a thick atmosphere. The disadvantage is that you can't put a decoupler under it, so I used an LV-T45 in the center (I think, could have been LV-T30. I forget the details).

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