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The Doodling Astronaut

Getting the best launch profile for eve

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Posted (edited)

Update: I have built all the tech for the mission... But I do need help on launching from Eve and best launch profile

Oh and if you want to give me bonus help you can help me give details on making a Moho orbiter or Gilly lander

Edited by The Doodling Astronaut

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Forget how much dV you need to make orbit. This is not the thin atmosphere of Kerbin, this is the gloopy purple monster.

So, it's not about stacking stuff until you hit a magic dV number and you are good to go. Oh, you can do that if you like but your craft will balloon into a unwieldy behemoth. 

What you need is a thin craft with the minimum number of stacks, where you have eliminated anything at all that adds drag and mass. You will need engines with optimal isp for a thick atmosphere, generally that means Vectors and/or Aerospikes. 

You will also fly to orbit differently than at Kerbin. You need to get out of the thick part of the atmosphere with low losses as quickly as possible but not so quick that you start to pile on the drag losses and then risk heatplosion. 

 On Kerbin if you can't make orbit you bolt on some more engine+fuel. On Eve you figure out what you can take away and how you can get good at flying to orbit. 

Check out the Eve challenges and the craft there.

Oh and don't be afraid of putting two craft down. One with your science and rover that is never going to get off the surface again and an orbit return craft. And don't plan on that doing anything else other than making orbit. Your mothership will need to rendezvous with it for the crew to EVA over along with the science.  

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9 hours ago, The Doodling Astronaut said:

Oh and if you want to give me bonus help you can help me give details on making a Moho orbiter or Gilly lander

Moho does not impose any specific design constraints; you just need oodles and oodles of delta-v.  Two main options:

1.  Build a normal-ish orbiter but keep weight to a bare minimum.  Put a good heatshield with full ablator and you should be able to return to Kerbin without a braking burn.  Keep adding stages to the back end until you have an appropriately-absurd amount of delta-v.  Your top stage could be a Spark or something, but you'll probably want to rely mostly on nukes behind that (once you reach LKO), of course.  Ideally you'll be able to stage off empty fuel tanks and engines along the way. 

2.  Build an ion-powered orbiter.  Moho is a great place to do this; since the sun is so strong you can get by with way fewer solar panels than normal.  This makes for a very light ship that's much easier to launch.  TWR is going to be horrendous, though, so you will likely need to do some burns outside of the Moho SOI, and split orbit burns into multiple passes.  Weight reduction is even more important here, unless you want to go on hour-long burns.  When I build stuff like this, I usually use a chemical stage to leave Kerbin, since solar panels would not be powerful enough.  You could also pack some expendable LFO tanks with fuel cells for this part, though.  

Gilly: Since Gilly's gravity is practically nil, delta-v is a non-issue here.  And you can (and probably should) use small engines so you can have some fine control over your maneuvers.  Some people use RCS thrusters only; I find it's easier just to use a little engine like an Ant.  The trickiest part is getting your lander to stay on the ground rather than bounce; hitting the ground with minimal velocity helps.  The new Breaking Ground friction surfaces might help here, but I haven't tried them for this. 

 

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1 hour ago, Foxster said:

 

Oh and don't be afraid of putting two craft down. One with your science and rover that is never going to get off the surface again and an orbit return craft. And don't plan on that doing anything else other than making orbit. Your mothership will need to rendezvous with it for the crew to EVA over along with the science.  

So I will need to eliminate all that is unnecessary, yes? So what if I have a stage that is on the bottom of the lander with the rover and science gear? Then with takeoff that can be my launch pad. I would also add descent fins to the side and decouple those too. And the Ladders, ect.

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My ascent profile was not the BEST but this lander i built but it's better to have some wiggle room for error (also i CANNOT thank the community enough for helping, i literally would still have been stuck there if not for them)

 

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18 minutes ago, Reinhart Mk.1 said:

My ascent profile was not the BEST but this lander i built but it's better to have some wiggle room for error (also i CANNOT thank the community enough for helping, i literally would still have been stuck there if not for them)

 

Is the high orbit possible to avoid?

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14 minutes ago, The Doodling Astronaut said:

Is the high orbit possible to avoid?

MOST definitely, i was just nervous that tipping over too early would flip it but in all honesty i could've and should've started the turn early

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Posted (edited)

So what would be the best amount for dV? And how to stage. Oh, and how to get to the surface and back to the lander is one I still haven't found out yet...

Edited by The Doodling Astronaut

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29 minutes ago, The Doodling Astronaut said:

So what would be the best amount for dV? And how to stage. Oh, and how to get to the surface and back to the lander is one I still haven't found out yet...

That depends entirely on how good your craft is. Somewhere over 6800 dV certainly. 

Staging is pretty much your ordinary affair. You drop tanks and engines when empty. 

Getting the crew onto the surface and back to the capsule on top of the craft can be done with a disposable lander can (maybe attached to your disposable science stuff) on the bottom and transferring the crew from it to the capsule.

 

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4 minutes ago, Foxster said:

That depends entirely on how good your craft is. Somewhere over 6800 dV certainly. 

Staging is pretty much your ordinary affair. You drop tanks and engines when empty. 

Getting the crew onto the surface and back to the capsule on top of the craft can be done with a disposable lander can (maybe attached to your disposable science stuff) on the bottom and transferring the crew from it to the capsule.

 

Foxster was one of the main people who helped me with my design (also hi Foxster :D)

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Just now, Reinhart Mk.1 said:

Foxster was one of the main people who helped me with my design (also hi Foxster :D)

Hi, mate. And g'nite ;) 

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Watch for TWR, Delta V and Aerodynamics, with 12 Km/s and good Aerodynamics and Fine TWR, you can make a Direct Ascent Eve Ascent Vehicle (For reasons...i feel like...Eve isn't Monstrous enough), also, for Moho Orbiters, you need to Capture in The Inclination Intersect that's closest to Kerbol, Capture should be around 1.7 Km/s, and i recommend NERVAs, for Gilly Landers, try limiting Thrust.

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Posted (edited)

Search for threads with Eve ascent 

Like @Reinhart Mk.1 said: The help of community is fantastic and there us a lot to learn.

Key points: Reduce drag, reduce weight.

An autopilot mod like MechJeb or GravityTurnContinued helps If your pilotink skills suck. Without GravityTurn I wouldn't have made it. 

Another trick: Land on higher biomes ( midlands, highlands, peaks etc) even a few hundred meters can make a big difference on Eve.

Edited by jost

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3 hours ago, jost said:

Search for threads with Eve ascent 

Like @Reinhart Mk.1 said: The help of community is fantastic and there us a lot to learn.

Key points: Reduce drag, reduce weight.

An autopilot mod like MechJeb or GravityTurnContinued helps If your pilotink skills suck. Without GravityTurn I wouldn't have made it. 

Another trick: Land on higher biomes ( midlands, highlands, peaks etc) even a few hundred meters can make a big difference on Eve.

pretty cheeky of me not to mention that the spot on eve where i launched was very close to the highest point on the planet (i.e. i can't remember but around 5000m above sea level... :D (it takes a bit to get an accurate landing but it's worth it)

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16 hours ago, Foxster said:

That depends entirely on how good your craft is. Somewhere over 6800 dV certainly. 

Staging is pretty much your ordinary affair. You drop tanks and engines when empty. 

Getting the crew onto the surface and back to the capsule on top of the craft can be done with a disposable lander can (maybe attached to your disposable science stuff) on the bottom and transferring the crew from it to the capsule.

 

Okay thanks my first prototype is complete but I'm on mobile right now so I can't upload it. 

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So then that brings the next question: will a biome map work? I can't find the highest peak but I have landed in the eve mountains before. My first ever mission actually was there.

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2 minutes ago, The Doodling Astronaut said:

So then that brings the next question: will a biome map work? I can't find the highest peak but I have landed in the eve mountains before. My first ever mission actually was there.

I just eyeballed it, i found the highest point via google (took some time to find a decent 3d map) but it took a few tries to not landing on a slope :D hold up i'll try to find it for ya

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This was way over built, as mission requirements were 3crew w/hab direct ascent to Kerbin from shores. But it does kinda illustrate the  Δν  comments, as it left the ground with about 7500m/s (vac).

Feel free to glean any info you want from it.

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For Moho you can massively  reduce the ship mass by using a kerbin-eve-moho grav assist, or even better a K-E-E-M route.

Like 3km/s instead of 5km/s+

The window is not very large though.

 

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Posted (edited)

@Reinhart Mk.1 thanks for the message at highest point on eve. So I need to mixture all the surface features are find-able at the site first...

2 hours ago, Muetdhiver said:

For Moho you can massively  reduce the ship mass by using a kerbin-eve-moho grav assist, or even better a K-E-E-M route.

Like 3km/s instead of 5km/s+

The window is not very large though.

 

How long would that take? I see most videos take over my 10 year standard

Edited by The Doodling Astronaut

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Posted (edited)
26 minutes ago, The Doodling Astronaut said:

How long would that take? I see most videos take over my 10 year standard

Depends on the Planning, but quite...yes, and here's my Direct Ascent Eve Lander.

GDrXZHy.png

Edited by GRS

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Update for people helping me!

So the lander has an update: I will attempting a landing somewhere altitude wise: 5000-7500. I have one problem though I can't find a mountain that has a flat top... if you can find good coordinates do message or reply!

Here is my past landers to Eve.

My first ever lander at eve landed at an altitude of 5500!

eve-mission.png?w=1202&h=

My next mission happened with an altitude at 1100

detatched.png?w=1250&h=

The latest mission landed at a similar altitude but was more north. 

powerful-rover.png?w=1500&h=

The last mission gave me the conclusion that I need to find a flat high area. But the first mission showed that it's pretty steep in the mountains

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Posted (edited)

You need a Powerful Lander if you are to Land on Lower Areas and still make it through, that thing I posted was capable to land on Lower Areas, might also be able to Accomplish Sea Level Landings, Fairings play an Immeasurable role in Aerodynamic Huge Landers.

Highlands are normally near The Seas, in the Different side from The Crater Lake, normally has 3 Km ASL...

Edited by GRS

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Posted (edited)

I'm guessing you are mostly looking for equatorial, so check out this area...

2te1G0n.png

It has rolling hills around 2000-3000m. Not as high as some places but there are plenty of flatter or gently sloping spots. 

There are a couple of alternatives...

Build a craft that can make orbit from anywhere. An efficient craft <30t can make orbit from sea level.

Mobile ICBM-like. Adds a fair bit of complication but could be fun.  

Edited by Foxster

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10 hours ago, The Doodling Astronaut said:

@Reinhart Mk.1 thanks for the message at highest point on eve. So I need to mixture all the surface features are find-able at the site first...

Not if you bring a rover. If a feature is not in your current biome drive to another one and return later :)  That's actually the mission profile I plan for my Eve mission on my current career game: 
1. Bring AscentVehicle first, land on higher evelation. 
2. Bring a rover with crew with the next transfer window. Do science with as many biomes until I get bored. 
3. Drive to AscentVehicle, transfer crew and science, orbit to Eve
4. KerbinReturnVehicle rendevouz with AscentVehicle, Crew returns to Kerbin


 

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This is lander that got me back to orbit and dock with mothership.

 

it has a refueling station attached and some engineering tweeks.

 

it was really painful to succed in EVE landing & return mission

 

As you see, it has landing platform, which was only that had fuel for braking  near surface, to make smooth landing. 

 

tou5YyZ.jpg

 

tYA5Kd1.jpg

 

1zdDiAJ.jpg

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