Eve Crew Lander - ATTEMPT 2

[Guest]

Alright here is my second attempt at making an Eve crew lander. please give me concepts or actual working models. Thanks

Actual things I need solutions

How to transport a kerbal back to surface

What causes the most drag (Ex: Ladders)

How many stages is recommended 

Edited January 6, 2020 by Guest

[Snark]

45 minutes ago, The Doodling Astronaut said:

Alright here is my second attempt at making an Eve crew lander. please give me concepts or actual working models. Thanks

There's a sub-forum, The Spacecraft Exchange, where lots of folks share their craft for all sorts of missions.

Suggestion:  search for "Eve" in that forum, I expect you'll get a fair number of results to look at. 

[AHHans]

Well, landing crew (or anything) on Eve is pretty easy: just make sure to have enough heat-shielding (e.g. the inflatable heat shield in a configuration that doesn't flip around) and parachutes. Getting from Eve back into orbit is another issue.

I would suggest to design your own craft for the Eve ascent, it is hard but also fun. Getting that done gave me the one of largest sense of accomplishment I got from KSP.

If you don't want to do the design yourself, then you can search on KerbalX for a suitable craft. One possibility would be my Eve Transportation System , but that is somewhat specialized because it was designed as a reusable shuttle system from transfers (of crew) between Eve's surface and low Eve Orbit and back. So I would recommend to use the search function of KerbalX to search for a craft that fits more closely what you want.

[AHHans]

P.S. I finally made my 3 person Eve expedition ship available on KerbalX: Eve Anywhere. In particular in 1.8.1 it is rather finicky to fly, but it does work and I use it for what I think is what you want to do.

P.P.S. When you want to change your question, it is better to add a new reply to the thread rather than just editing the original post. I only now saw that you changed your question after I wrote my last reply.

On 1/6/2020 at 1:26 AM, The Doodling Astronaut said:

How to transport a kerbal back to surface

Well, I made only craft that used the BG propellers to ascend to at least 10km on solar power. From there I need about 5000 m/s dV (at the pressure there!) to get to orbit. And of course a TWR greater than one until I'm in a high enough ballistic trajectory.

On 1/6/2020 at 1:26 AM, The Doodling Astronaut said:

What causes the most drag (Ex: Ladders)

You want to throw away everything that you don't absolutely need before your ascent. Put ladders, landing gear, and other similar stuff on decouplers and stage them away when/before you start. Part of my design process was to go through every single item on the ascent module and think if I really need it, and it the mission will fail if I don't have it. (Yes, yes, and then I added some extra science experiments, but that was after I saw that it will work.)

Another thing that adds extra drag is uncovered connection nodes. Even stacks with nosecones add drag, so try to avoid side-mounted structures if possible.

On 1/6/2020 at 1:26 AM, The Doodling Astronaut said:

How many stages is recommended 

The number of stages doesn't really matter. Allegedly there are Eve SSTOs, but dropping tanks every 5 seconds at the start is also a valid option.

Some other tips:

• Pay close attention to the ISP of the engines in the dense atmosphere on Eve, most people use the vector or aerospike because they suffer the least.
• Close to the sea level every meter of altitude that you start higher helps - mostly because of the ISP of the engines. Many rocket-only crafts need to start from a mountain in order to make it to orbit.
• Until you get to 20km or so you just go straight up. You need to get out of the worst part of the soup around Eve before you can start a gravity turn.
• That also means that for the first stages drag is less of a problem. (I.e. you can have some draggy parts on your craft, if you stage them off soon enough.)

Edited January 11, 2020 by AHHans
Changed wording to improve clarity.

[Quoniam Kerman]

Also EVE SOI is bigger than Kerbin's so for the last part of the trip make sure you have a interplanetary ship waiting in LEO.  The ship to get back to orbit will subsequently be smaller and easier to design unless you are bad at orbital rendezvous.

 

[Guest]

I have this picture of my past Eve Crew lander, didn't make it farther than the drawing board. 

I probably should have specified what I actually had problems with. I first had a problem of how to land the lander with it's size and all. The second problem I had was how to get the kerbal out of the lander and crawl it down to the surface which is why I had a hard time designing such a lander. But it can be done!

[Laie]

2 hours ago, The Doodling Astronaut said:

I first had a problem of how to land the lander with it's size and all. The second problem I had was how to get the kerbal out of the lander and crawl it down to the surface

Example:

For the landing, all fuel is in the bottom tanks for low CoM. Note that this still needs airbrakes on top, set up for pitch/yaw controls, in order to stay behind the heat shield. For many larger vessels, the only workable solution is to have heat shields on both ends -- this comes up pretty regularly on the Gameplay Questions forum, search a little and you will find plenty of examples.

There's also a crew module in the base, for easy access. Kerbals can board there and teleport transfer to the top. Science can be moved to the top by means of the science container, which will detach before ascent.

[Quoniam Kerman]

Make a more compact lander height wise with side boosters mounted in asparagus setting instead of a tower. But don't build it too large to ensure aerodynamic stability on reentry.

Edited January 12, 2020 by Quoniam Kerman

[jost]

I had the same question to bring three kerbals to Laythe surface and back: 

 Most important were reducing drag, getting rid of not needed parts and launching from a higher location (e.G. Highlands or Midlands biomes instead of  sea level)
Another point was to play with the gimbal settings of the engines (Vector is great for Eve lifters, it's gimbal not so much)

A good way to test your design is to try whether it can return to orbit with GravityTurnContinued (seems to work better on Eve than MechJeb).

 

Edited January 12, 2020 by jost
Added Gimbal