Eve Lifting and 0.23.5/.24

[GigaG]

So we all know that Eve is the probably hardest planet to make a round-trip landing on (excluding Jool, considering that the Kraken lurks on its "surface.") My question is whether somebody has made an Eve lifter with the new super-engines. Do they assist with defeating the thick atmosphere and strong gravity? Or are they too impractical to carry to Eve?

As for testing on Kerbin, how can I test on Kerbin that my lander will make it? (I know on Duna, the test is that if you can make it just short of Kerbin orbit, you can make it into Duna orbit.) Should I aim for an ejection from Kerbin at a certain velocity for a test run?

Edited July 26, 2014 by GigaG

[Col_Jessep]

It depends on what you want to lift from Eve's surface. If you put your Kerbal in a command chair you are better off with 1.25m parts imo. If you want to land with a capsule things become larger, much larger. Still, I would try to avoid using the new parts for an Eve lander - but they are great to get your lander into LKO! ;P

To build your Eve lander you probably want to use Kerbal Engineer. Aim for 12000m/s delta-v and select Eve as reference body in KER. Try to land on a mountain to make things easier. For a rule of thumb test: Your Eve lander should be able to reach orbit around Kerbin without staging. That's a very rough estimate though and I wouldn't rely on it.

[technion]

So we all know that Eve is the probably hardest planet to make a round-trip landing on (excluding Jool, considering that the Kraken lurks on its "surface.") My question is whether somebody has made an Eve lifter with the new super-engines. Do they assist with defeating the thick atmosphere and strong gravity? Or are they too impractical to carry to Eve?

As for testing on Kerbin, how can I test on Kerbin that my lander will make it? (I know on Duna, the test is that if you can make it just short of Kerbin orbit, you can make it into Duna orbit.) Should I aim for an ejection from Kerbin at a certain velocity for a test run?

I've made several efforts at this. The newer NASA parts are incredibly helpful at getting something capable of an Eve ascent, all the way to Eve. Previously, my lifters would have a monstrous lifter underneath them, and still empty their first two stages getting in orbit. Then I'd go out send a tug, then make a third launch with a refueller before departing. The new parts make things way easier.

That said, trying to build your actual lifter using a 3M engine is insanity.

[r_rolo1]

That said, trying to build your actual lifter using a 3M engine is insanity.

What I've found is that the best alternative to Eve launches is the copious use of aerospikes, given that they are the most insensitive to atmosphere of the stock engines ( and they aren't as bad as that engines, in spite of being a shadow of what they were in far away versions of the game ). People tend to underestimate the effect the bigger atmospheric pressure has on the engines in Eve ( that and the quite small terminal speed ... it is quite wierd to keep 50 m/s for 10 km up ) ...

[Red Iron Crown]

Jouni here on the forums made a 7-kerbal Eve return lander using some of the Kerbodyne parts, can't seem to find the post right now though.

As for testing, the best option is Hyperedit, though it's a bit cheaty. If you want to do some testing on Kerbin, you can add tanks to simulate the extra weight that will be exerted on the ship on Eve, useful for testing landing gear. For testing TWR, limit your engines to about 55% to achieve a similar effect. (Don't do both, obviously.)

Here's a design being tested on Kerbin, the 2.5m tanks add about 70% to the ships mass to simulate the stresses the gear will see on Eve.

The amount of delta V required is fairly staggering, about 12km/s from sea level and about 8.5km/s from the highest mountaintop. It takes some careful design to combine the large dV requirements with the high TWR needed, I haven't been able to do so without the aid of a calculator like KER or MechJeb.