Duna Sample Return

[Horn Brain]

I got excited when I saw this: http://www.forbes.com/sites/michaelvenables/2013/08/02/nasa-is-still-dreaming-about-tomorrow-mars-ascent-vehicle/

And I wanted to build my own sample return system. Here's the mission plan:

Misson 1: Landing Site Selection.

Send an orbiter to Duna to scout for a landing site:

It's called "Eval" for "Evaluation" and also to sound like Evel Knieval, since I sent it on several deep dips into the Dunan atmosphere "for science".

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Mission 2: Caching.

Send a Curiosity-like rover to Duna to "collect samples" (Come on Squad, add this mechanic!) and store them in a small, retrievable capsule. This mission is like the 2020 rover that will use spare parts from Curiosity to look for evidence of past life and store a sample cache for potential return by a future mission. I even used a sky-crane by including the Kerbal Attachment System mod. I called it Fennec after the desert fox. This was really fun to fly:

Landing

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And Roving

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Mission 3: Fetch the nut and run it up the tree.

Sciurus (Latin for squirrel, since it's supposed to find a "nut" and store it "in a high place") consists of the fetch rover (not strictly necessary since I can just keep driving Fennec forever, but we're having fun) attached to the bottom of the ascent vehicle, which is pretty freaking tiny. It has tons of decouplers and legs and gizmos attached to it because I decided to try and do the mission without using Damned Robotics. The result is that the ascent vehicle has to land vertically to deposit the rover (via sky-crane again!), then tip over on its side so that I can wiggle the nose cone on with a tiny docking port, then prop itself back up so that it can launch again. Phew. This is going to be fun:

So far, I've landed the vehicles about 22 km from Fennec:

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It worked! Here are some pictures of the retrieval and the launch:

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Mission 4: Orbital retrieval.

My launch vehicles for the previous two missions were way overdone, so this time I decided to go lightweight. The best way to do that is with ion propulsion. The vehicle will be called Space Bud (Orbital Retriever), because it's playing fetch and I'm tired of coming up with appropriate names. It launches on just one large SRB and one medium 1.25m fuel tank.

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Imgur was being weird and wouldn't accept the last two pictures, which were just the sample splashing down after the chute deployed. Nothing you haven't seen before.

Quite a fun mission, and a good challenge! I have fun with the tiny probe parts because you can do things like have a Duna ascent vehicle the size of a kerbal, and fly all the way from LKO to Duna and back on a single tank of Xenon. If anyone wants any of the vehicles, I'll provide the craft files.

Edited August 8, 2013 by Horn Brain
Added return phase.

[Scorpi15]

I think you have a probe on the sky crane, and that is why it cuts the engines.

[regex]

Nice work and an interesting read! I might try this myself for future Moho attempts (if I can actually get a lander down safe... My next launch window goes there), it looks like fun.

[Horn Brain]

I think you have a probe on the sky crane, and that is why it cuts the engines.

Well, you're right about having a probe, but with my rover when I detached the cable it jumped to controlling the sky-crane and my throttle settings stayed the same. With this version, it jumps to controlling the payload, even though the root part is the sky-crane probe... Oh I just figured it out. When I jettisoned the previous stage (which had a small probe on it to deorbit it) it must have automatically selected one of the other probes to control from, not the sky-crane probe. Just another thing to check out before landing my next package.

[Horn Brain]

Launch of ascent vehicle posted!

I should add that everything in this post has been one-take. I did all my testing on Kerbin and everything is live. Failures would have been dealt with by salvaging or launching a new mission.

Squad, I want tiny radial decouplers, please. The little attachment points left behind by the big ones look awful.

Edited August 7, 2013 by Horn Brain

[Horn Brain]

Final retrieval completed and posted. Craft files available if you want any of them. The only ones I really think are worth sharing are the Fennec Rover and the Sciurus ascent vehicle and rover combo.