How to land at Eve???

[Anonymous49]

On 2/24/2021 at 12:56 PM, Kerbals_of_Steel said:

For anyone interested, I put up a slightly simplified version on KerbalX:

https://kerbalx.com/Mobryan71/Eve-Probe

Basically just took off some of the extra science that required non-critical mods. Still requires both DLC's and Universal Storage 2.

not trying to complain but 66.5 TONNES! My first mun lander W/ FAIRING is 1.4 tonnes.

[VoidSquid]

If you check the part list, it is clear that the craft file includes all stages, not only the lander itself.  

[Anonymous49]

41 minutes ago, VoidSquid said:

If you check the part list, it is clear that the craft file includes all stages, not only the lander itself.  

ok  the photo in the file shows only the lander  

[VoidSquid]

No offense, but (thoroughly) checking stuff before posting is usually not a bad idea at all   

Spoiler

You might ask what gave me idea to check things in this case. It is what you already mentioned, craft mass 60-somethings tons. This simply doesn't match with the images. Big discrepancy, isn't it? And exactly this discrepancy made me check the part list, where I found, among other parts, the Pollux SRBs. Obviously, these are used to bring the rocket into orbit, not for landing at Eve.

That is, by the way, the reason why I have those two lines in my signature, I wish more people would care for that.

Edited February 26, 2021 by VoidSquid

[Kerbals_of_Steel]

6 hours ago, Anonymous49 said:

not trying to complain but 66.5 TONNES! My first mun lander W/ FAIRING is 1.4 tonnes.

66.5 tonnes is ready to launch weight with the probe, booster, fairing, and interplanetary yeet stage. The probe itself is ~2 tonnes and the  heatshield brings it up to ~ 3 tonnes.  It could be launched on a 1.25m stack, but since you need Making History for the correct heatshield, I just used MH parts for the whole booster.

I didn't put up a pic of the booster since it's a basic pointy end up, flamey end down rocket. I did put the detailed description in the text, though

"The booster consists of a 1.8m Pollux SRB pushing a Cheetah second stage for orbit and interplanetary yeeting. From LKO, the second stage has ~2000 m/s delta V, enough to keep the transfer window open for a few weeks beyond the optimal period. The probe itself has ~400m/s of fuel for fine tuning the approach, power production and a certain amount of retrograde propulsion. Note that the probe itself has the thrusters on the top, so after third stage separation the control point on the guidance core must be swapped from Default to Reversed."

Edited February 26, 2021 by Kerbals_of_Steel

[18Watt]

3 hours ago, Kerbals_of_Steel said:

66.5 tonnes is ready to launch weight with the probe, booster, fairing, and interplanetary yeet stage.I

That is an impressive number, especially for a vehicle going to the surface of Eve!   I tend to get lazy building vessels, and just make them way more massive (and expensive) than they really need to be.   Having a ridiculous amount of excess DV solves a lot of problems quickly.

I’d give yourself a pat on the back for making a successful Eve lander with a launch weight that low.   Also, thank you for reporting back on solutions that ended up working- I was especially interested in the issues you had with heat being transferred in unexpected ways, and how you solved that problem.

[wpetula]

On 2/21/2021 at 8:23 PM, Kerbals_of_Steel said:

but how do people land on Eve

The real question is how do people leave Eve? 

[18Watt]

8 minutes ago, wpetula said:

The real question is how do people leave Eve? 

That’s another good question.  I’m following this thread because eventually I’ll want to complete a ground circumnavigation of Eve for the Elcano Challenge.  I’m saving that for last, for several reasons.  One reason being, I’ve never successfully brought anything back into orbit of Eve from the surface.  Not even a strut, let alone a Kerbal.   So the most likely scenario is any Kerbal I send to Eve’s surface will spend the rest of their life there.

Another challenge is getting stuff through the atmosphere without blowing up, and I was happy that @Kerbals_of_Steel found a few of my suggestions useful.   But yep, I’ve been playing KSP since 2012, and can do almost anything successfully.  Except get anything from the surface of Eve to orbit.   For me, landing anything on Eve is exactly the same as landing on Jool- I will never see that thing again..

[Spricigo]

 

18 hours ago, wpetula said:

The real question is how do people leave Eve? 

Eve is so cozy. Why would anyone want to leave? 

 

 

[king of nowhere]

22 hours ago, 18Watt said:

  Having a ridiculous amount of excess DV solves a lot of problems quickly.

 

19 hours ago, 18Watt said:

That’s another good question.  I’m following this thread because eventually I’ll want to complete a ground circumnavigation of Eve for the Elcano Challenge.  I’m saving that for last, for several reasons.  One reason being, I’ve never successfully brought anything back into orbit of Eve from the surface.  Not even a strut, let alone a Kerbal.

you yourself stated the solution to your problem

you just need a lot of deltaV. i tend to use 3 stages; one to go from the ground to 10 km of altitude, straight up. it has a lot of engines because they are less efficient in eve. the second reaches all the way to 50 km, where i should be in a suborbital trajectory or close enough. it starts to circularize around 20 km, the atmosphere is still too dense before that. the third stage starts around 50 km  and circularizes. of the 8000 m/s listed as necessary for eve, 5000 are really just to get out of the first 50 km of atmosphere.

it is even possible to make an eve ssto with a spaceplane that uses propellers and wings to get to at least 15 km of altitude; this removes most of the cost. i've seen people doing it; my design fell short by 1 km/s, though.

[Spricigo]

33 minutes ago, king of nowhere said:

you yourself stated the solution to your problem

Is not that the easier part?

Currently the 1st stage propeller is the way to go. (jets don't  work and a hand full of rockets barely do)

[king of nowhere]

2 minutes ago, Spricigo said:

Is not that the easier part?

Currently the 1st stage propeller is the way to go. (jets don't  work and a hand full of rockets barely do)

i guess it depends on what you are trying to optimize. if you are optimizing mass and cost, then i guess it's right, it's cheaper to make a first stage propeller than to strap big boosters to everything.

on the other hand, if you go for simplicity, once you already have a big rocket, adding moar boosters (here boosters is defined loosely as lateral fuel tanks with extra engines, because it's better to use liquid fuel) is easier than devising an entirely new propulsion system. especially because propellers are tricky. it's also much easier to land a rocket on parachutes than it is to land a multi-hundred ton spaceplane.

as far as i am concerned, the ideal would be an ssto, so that i could make a grand tour and recycle the spacecraft entirely. if that lofty goal cannot be achieved, then i'd rather go simple

[Spricigo]

36 minutes ago, king of nowhere said:

on the other hand, if you go for simplicity, once you already have a big rocket, adding moar boosters (here boosters is defined loosely as lateral fuel tanks with extra engines, because it's better to use liquid fuel) is easier than devising an entirely new propulsion system.

I see your point. The problem is that one is already deep in the land of diminishing returns at this point and may easily fall in the trap :  moar booster > moar fuel > moar booster. (Throw in some moar struts and moar bugs for seasoning) .

In practice is often simpler to put some crude propellers than fine tuning  the rockets.