Eve.

[Shna_na]

We all know that Eve is the planet from which escape is near-impossible. What I want to know is the following:

• If I were to intercept Eve in such a way that I am transferred straight from solar orbit to an impact trajectory with the planet, would the rate of descent be too powerful for parachutes to deploy in such a dense atmosphere without tearing a craft, which is large enough to orbit and escape Eve from the surface, in half?
  
• If I do survive such a descent, would landing at a high altitude be a better option than landing at a low altitude? A higher altitude would make the return easier, but would it be safe at those speeds?
  

A further question is also floating around my mind, though it is a little less likely to happen:

• If I were to land on Gilly before Eve, would it be more efficient to aerobrake to low Eve orbit and then burn for Gilly, or just go straight for the little rock?
  

Edited April 17, 2014 by Shna_na

[Red Iron Crown]

You're better off going for an aerobraking trajectory to burn off your transfer speed in several passes, less likely to break up your ship than a direct impact trajectory.

Return from a mountaintop is far easier than sea level, but both are definitely possible.

You will save significant dV if you aerobrake in Eve's atmosphere before going to Gilly.

[Shna_na]

You're better off going for an aerobraking trajectory to burn off your transfer speed in several passes, less likely to break up your ship than a direct impact trajectory.

Return from a mountaintop is far easier than sea level, but both are definitely possible.

You will save significant dV if you aerobrake in Eve's atmosphere before going to Gilly.

That was pretty simple and straightforward, thanks .

[capi3101]

Yeah - the only thing about Eve that's even remotely difficult (well, compared to any interplanetary mission) is the ascent from its surface, but boy howdy is that ascent difficult. Designing a vehicle that can do it is one of the major challenges of the game; I have yet to do it my own self (really need to unpack the vehicle I was going to make the attempt with in 0.23.0 and see if the optimizations in 0.23.5 would make it any easier to fly; its part count was what held it back, and the one I designed in 0.23.5 doesn't want to steer).

[cantab]

As for Gilly, I believe the best approach would be to aerocapture into an orbit as similar to Gilly's as possible.

[Redshift OTF]

Eve's atmosphere is so thick it will massively slow you down before you need to deploy chutes. They are more for the final descent when the ship has slowed down enough.

[Vanamonde]

Why ever would you *want* to set yourself on a surface impact trajectory? There's no advantage to making your passage through atmosphere faster.

[Jimbimbibble]

It's a good idea to used drogue chutes and then main chutes. Set them up in such a way that you can jettison your chutes and landing gear before liftoff. If your return module is light enough, you can mount 2 large legs on a large radial decoupler and ditch them on liftoff.

[Red Iron Crown]

Using a command seat instead of a more traditional pod makes it easier, too. Don't forget a probe core to guide it down and ladders to get to the seat.

[Tokay Gris]

Using a command seat instead of a more traditional pod makes it easier, too.

But don't forget that a Kerbal weights something. As far as I know, those little green men don't weight anything while in a capsule, but have a weight in a command seat.

Since the ascent from Eve surface is difficult at best, these few kilos can make the difference between success and failure.

[Vector]

Why ever would you *want* to set yourself on a surface impact trajectory? There's no advantage to making your passage through atmosphere faster.

There is an advantage: if you're not using MechJeb then it's easier to target a particular spot on the ground. I have managed to reliably land on the island within the large circular lake, just to see if I could. At a shallow angle it would be difficult without some assistance.

[Shna_na]

Why ever would you *want* to set yourself on a surface impact trajectory? There's no advantage to making your passage through atmosphere faster.

By surface impact trajectory, I was referring to a path that would lead me to collide with the planet. I generally try not to make it direct, usually a periapsis of around 30km for Eve.

[Zad Fnark]

Hi Guys,

I thought I'd attach this here, and not create another Eve thread. My search skills seem lacking, as I know it's come up before.

I thought I've seen a good rule of thumb before of having a lander capable of orbiting Kerbin with 25% fuel remaining also being able to get off Eve. Is this about right?

What would be a good orbit height for the CM to park in for this?

Thanks

ZF-

[EdFred]

Hi Guys,

I thought I'd attach this here, and not create another Eve thread. My search skills seem lacking, as I know it's come up before.

I thought I've seen a good rule of thumb before of having a lander capable of orbiting Kerbin with 25% fuel remaining also being able to get off Eve. Is this about right?

What would be a good orbit height for the CM to park in for this?

Thanks

ZF-

Not to laugh, but I did. I thought almost the same thing early on. It's not even close.

It takes about 3 times the amount of dV to get off Eve. So, whatever you used to get into Kerbin orbit, you need to have DOUBLE that remaining. Not to mention Eve has higher gravity. There is no testing it on Kerbin to see if it will work for Eve. You need Mechjeb or Kerbal Engineer or another mod to give you a dV and TWR analysis. You'll need a dV of around 12,000m/s, and I aimed for a TWR of at least 1.3 on Eve.

I used an orbit of 105km above Eve for docking rendezvous.

Edited April 17, 2014 by EdFred

[cantab]

Build a rocket that can reach LKO. Then build one that can get THAT into LKO. You're still short of what you need for Eve.

[EdFred]

You aren't kidding.

The first 9,000dV is easy.

[Zad Fnark]

Thanks.

It's not too hard to build something which can accelerate quickly off the ground, but you have to haul that pig up to begin with.

I currently have a station over Kerbin with 3 orange tanks attached. Maybe I'll have to assemble something in orbit.

ZF-