Return mission from Eve - GROUND LEVEL

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A return trip to Eve is one of the more interesting missions. The ultimate guide to this, in the form of Scott Manley's youtube series, established a highly efficient method of doing so. You'd have to be an idiot to go out of your way to take a LESS efficient path. Today, I am that idiot.

Lander design is, obviously, the major component of this. All my previous landers in Duna and Laythe were aerospike driven. That worked great- but by the time you've strapped enough aerospikes and fuel together to achieve orbit from Eve at any level, you've got a ridiculous craft. They say you can move anything with enough dv - but it's not totally true. If it's not practical limits about what you can land without having explode, it's limitations on what your CPU can handle.

Meanwhile, the inspiration from Scott's craft, featuring a series of small rockomax powered units was very appealing. How did it scale up though? Not great unfortunately. You reach a point where the outer stages run dry in two seconds.

The design was therefore, a hybrid. Featuring an outer shell of aerospikes, and an inner section of small tanks and rockomax engines. I intend on using this to achieve orbit.

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There have been several attempts here.

Lander one, after making the flight the whole way to Eve, came down on a 3km mountain (through sheer luck) and was incredibly close to orbiting from there.

For the second revision, no problem, more fuel should help. Instead of placing that fuel on the outer stage where I planned, it landed on the inner stage. The problem with this was, after losing some of the outer engines, the TWR dropped enough that, at about 10KM, the speed went to 0 and then we started falling back to ground. Not great.

Third revision aimed to fix that, and it almost did. From a height of 1800, it was able to build an appropriate Apopsis, kill the engine, and hang out two minutes until it got there. At which point, it was out of electricity and couldn't fire up to circularise. Yes, the deliberate decision that we wouldn't need the weight of a battery on the last stage had killed this revision.

The fourth time I prepared to haul a lander the whole way there, it looked like this.

Lifting this sucker into orbit takes quite an effort. I'm certainly not happy with the small engine -> large tank join, which would buckle under too much thrust.

Getting there.

This lifter violated one of my cardinal rules - I hate launching just to refuel. It was just so heavy that attempts to expand the lifter kept failing. Here you can see it circularising.

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This is my transport booster. It was built to provide extra thrust, but it serves to drop just under three grey tanks to a refuelling rocket.

Dumping the lifter.

Coming in to dock.

Detaching after transferring all its fuel to my lander. It's still over 2000 points down.

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A whole new transport booster on its way.

Docked and filling up the lander.

Firing the outside tanks on the booster. Finally - we have full tanks and nuclear engines.

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Despite being called "laythe traveller", this transport has become a staple on many of my missions.

Once in orbit, we can kill the mainsails.

Total weight of the assembled craft, ready to inject to Eve.

How it looks.

When enough fuel is burned, you can undock the transport and finish the capture on the booster.

Approaching Eve

Coming in for landing. The booster will be destroyed here.

Parachutes leading the water landing.

Touchdown! My Eve ascender is sitting in water.

[Daddy Cecil]

You are an idiot for landing in water. Yet you are ingeniously stupid for trying to get to orbit. Good luck :salute:

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Stupid indeed. This is one of those reasons SRBs exist. This rocket literally couldn't leave the water until I fired them. Roughly five seconds at full throttle and nothing moved until those SRBs started.

Here we see 12 aerospikes, 4 SRBs, and 20 of those radial rockomax engines getting us moving.

After alternating asparagus staging with droptanks, we get down to four aerospikes powering on.

One of the final stages.

Ready for our circularising burn. Just look at the dv required... it's amazing what a punch a tiny tank + engine can pack.

Whoa!

Through the magic of quicksave.. back in orbit to plan a ground landing for rendezvous with the team.

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In the interests of "doing it for real", here's where we ended up planning our ship (where a rover could get to it).

Here's the rocket that will be doing the main Eve mission. The left side features an ion driven lander destined for Gilly (with an extra tank as counterweight). The right features my lander with rover. Is this what people call a skycrane?

There's some interesting views of the docking ports here during the high-thrust take off.

Circularising.

The same transport seen earlier, launching again.

Starting the ejection burn, amazed again at how effective it is when you still have some mainsail fuel to burn.

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The whole thing can be seen as it travelled like this. You can see here - though I didn't notice it until getting to Eve, the small liquid rocket booster we attached to the bottom of the Gilly unit has sheared off. I didn't expect it to be necessary, but now we'll have to find out the hard way.

Showing the statistics of all components.

The build of this rocket couldn't handle as much aerobraking as was necessary, so it took a small burn to get captured.

Tell me again why I contemplated requiring the transport booster? The orange tank at the bottom is completely full.

I put the mothership on a matching orbit with Gilly. It seemed to have enough fuel to want to take advantage of.

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Why do I do all the cool stuff in the dark? EVA sending a kerbal to the Gilly probe.

Detached. Wow that's tiny for something heading off to a moon landing.

Intercept.

Coming in. Note the navball still says "orbit". The fact I expected it to automatically change to "surface" led to several high impact crashes.

Incredibly slow waiting for gravity to pull us down.

Almost...

Protip: you can land at 0.6m/s and still watch a gigantor explode. Luckily I also packed generators on this flight and can fold these away.

Success kerbal!

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EVA into our lander.

Detached and preparing for landing.

There is more than enough dv to plan an appropriate landing.

The fiery ascent.

Coming in for landing. This vehicle doesn't actually need to rocket assist the landing. But if you got em, use em.

This lander was specially designed to solve one particular issue: Every lander I had seen involved some form of "drop it from a short height". On Eve, that invariably meant something exploding. Here you see the lander just held above ground by the landing struts, which are shaking and shivering under the weight.

Now all we do is activate those gears and lift the legs, for the slowest ever touchdown by a rover. Then we can decouple and lift the lander back up.

Taking a sudden turn will send the detached decoupler to the side.

And we're away.

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It's over a 59KM drive. Sure, I could have tried to land closer, but frankly, even if it took a few hours, that's not that much in the scheme of this mission. Eve.. it's a lonely place.

It ended up taking about 35 minutes. Here we are at our launch vehicle.

Repairing the legs. Turned out to be pointless, they broke immediately, before you could even retract them.

Lift off!

Two stages into the launch. Now we're at a height that sensible people launch from.

Four stages in. By 5km, the lifter is much smaller and this stage lasts a lot longer because there's no fuel being fed anywhere.

At about 10km, the internal section of the rocket takes over.

Second last stage. It's amazing how far we still have to go at this point.

Orbit done!

Our hero kerbal awaits a pickup - dangerously close to the atmosphere.