Eve SSTO

[Gameslinx]

Hey all!

I'm halfway through my Single Stage to Nearly Everywhere mission, but unfortunately I won't be able to return from Eve. 

As I'm on my phone, I cannot post images.

Facts about the ship: ~68 tons, 72 parts, ~6450 LF, ~2100 O, 17,434 DV.

I can't take off from Eve since its atmosphere is thick and slowed my down, causing me to fail at getting any significant lift. I feel that adding wings will lower my DV even more, which I need to get to Moho/Jool.

Help would be appreciated!

[eddiew]

Basically your ship is about 1% the mass I'd expect from a stock Eve ssto  There's a reason most people don't bother...

[Plusck]

Assuming that you have a decent atmospheric ISP chemical engine in there (Aerospike or Vector), you have a vacuum delta-v of about 1000 m/s.

Since you can't use jets in Eve's atmosphere, you're either using modded parts or you aren't going to space today.

Assuming, next, that you are using an LV-N for the remaining LF, that gives you a dv of just under 5200 m/s.  So I think there's something wrong with the numbers there.
If that "6450" was a typo for "9450", that would give you 12,000 m/s remaining dv on the LV-N, but only in vacuum. In the atmosphere it'll be a fraction of that.

So basically I think you are never going to make orbit if you rely on using an LV-N in the atmosphere. Maybe possible after spending 3-4000 m/s dv with good atmo rockets lower down, but not before.

 

And if you are trying to use RAPIERs for this - you definitely do not have 17km/s dv. You have 986 m/s dv total.

[Gameslinx]

5 hours ago, Plusck said:

Assuming that you have a decent atmospheric ISP chemical engine in there (Aerospike or Vector), you have a vacuum delta-v of about 1000 m/s.

Since you can't use jets in Eve's atmosphere, you're either using modded parts or you aren't going to space today.

Assuming, next, that you are using an LV-N for the remaining LF, that gives you a dv of just under 5200 m/s.  So I think there's something wrong with the numbers there.
If that "6450" was a typo for "9450", that would give you 12,000 m/s remaining dv on the LV-N, but only in vacuum. In the atmosphere it'll be a fraction of that.

So basically I think you are never going to make orbit if you rely on using an LV-N in the atmosphere. Maybe possible after spending 3-4000 m/s dv with good atmo rockets lower down, but not before.

 

And if you are trying to use RAPIERs for this - you definitely do not have 17km/s dv. You have 986 m/s dv total.

Um no. Not using any nodded parts. 4 rapiers, and 2 LV-Ns. Kerbal Engineer is reading roughly 17,000 DV (I also have mining gear)

[Foxster]

A manned orbital flight from Eve requires a special craft. Under a particular set of circumstances and with particular design it is barely possible for an SSTO to do it but it can only just be considered a ship. Anything that is designed to go elsewhere too is unlikely to make orbit on Eve, unless I suppose it was the last destination and then you will have carried around a lot of craft at the other destinations just for use on Eve. 

Eve is a harsh mistress and needs treating with respect.   

[Blaarkies]

26 minutes ago, Gamel0rd1 said:

Um no. Not using any nodded parts. 4 rapiers, and 2 LV-Ns. Kerbal Engineer is reading roughly 17,000 DV (I also have mining gear)

KER is calculating your RAPIER's airbreathing mode, but Eve has no oxygen in it's atmosphere. To fix this, switch all rapiers over to closed cycle in the editor.

[Plusck]

52 minutes ago, Gamel0rd1 said:

Um no. Not using any nodded parts. 4 rapiers, and 2 LV-Ns. Kerbal Engineer is reading roughly 17,000 DV (I also have mining gear)

Ah, ok. As Blaarkies says, that's the air-breathing delta-v.

So starting at 68.0t, with 2100 Ox and 6450 LF, you will get 986 m/s dv (vac) out of your Rapiers. You'll then have 5187 m/s dv left for the LV-Ns. Your final ship mass will be 25.3t.
Unfortunately there is no way out of Eve's atmosphere, unless you turn on infinite fuel. Even if you did that, your TWR would be about 0.4 (maybe less, I'm not sure how well Rapiers do deep in the atmosphere), so I think you'd burn up before getting high enough to get the speed necessary to escape the atmosphere. I think you'd have to burn off most of your LF using the LV-Ns before even making the attempt with the Rapiers on infinite fuel.

[Gameslinx]

32 minutes ago, Blaarkies said:

KER is calculating your RAPIER's airbreathing mode, but Eve has no oxygen in it's atmosphere. To fix this, switch all rapiers over to closed cycle in the editor.

Well I'm planning on getting from Kerbin to Minmus to Eve using the airbreathing modes and the nukes, saving as much LFO as possible. Before eve I will retrograde burn to flip the orbit around, burning off all the excess fuel radially until there's none left. Then I'll be light enough to enter Eve's atmosphere safely using my drogues. 

Then I'll mine LFO from Eve and return to eve orbit using the closed cycle rapiers, then the nukes. Problem is that I need more lift, which adds more weight, but since eve has such a thick atmosphere, falling downwards may be harder 

[Plusck]

56 minutes ago, Gamel0rd1 said:

Then I'll mine LFO from Eve and return to eve orbit using the closed cycle rapiers, then the nukes. Problem is that I need more lift, which adds more weight, but since eve has such a thick atmosphere, falling downwards may be harder 

What you're trying to do is very nearly impossible. It's something hardly anybody has managed to do.

You should read this thread to see how impossible it is, including a video of how it can - just - be done. The video is on the previous page in this thread. The linked post is just to give some numbers:

So it weighed 270t empty and >1400t fuelled...

It's virtually all tank. It has mini drills and takes 3 years to refuel. It landed on a mountain. It got to orbit with about 50 m/s left in its tanks.

If you land nearer sea level, it is physically impossible to go the SSTO route: no engines have the ISP and TWR to do it.

So really, this is not something you can do with a craft that can fly.

[GoSlash27]

What @Plusck said.

 And even if you could do what you're proposing, you won't be able to do it with RAPIERs and nukes, since neither engine is efficient enough to be effective in Eve's thick atmosphere. Additionally, even if you had a ship that was almost completely fuel, you'll still be stuck in orbit with no way to refuel by the time you get there.

 Hate to say it, but I'm afraid you'll have to go back to the drawing board on this.

Best,
-Slashy

[Gameslinx]

34 minutes ago, GoSlash27 said:

What @Plusck said.

 And even if you could do what you're proposing, you won't be able to do it with RAPIERs and nukes, since neither engine is efficient enough to be effective in Eve's thick atmosphere. Additionally, even if you had a ship that was almost completely fuel, you'll still be stuck in orbit with no way to refuel by the time you get there.

 Hate to say it, but I'm afraid you'll have to go back to the drawing board on this.

Best,
-Slashy

OK. So using Eve for the grand tour is definitely out of the game. 

I visited Moho, Kerbin, Gilly, Minmus, Mun, Duna and Ike so far. Just need dres, the Jool v and Eeloo

[magnemoe]

11 hours ago, Gamel0rd1 said:

OK. So using Eve for the grand tour is definitely out of the game. 

I visited Moho, Kerbin, Gilly, Minmus, Mun, Duna and Ike so far. Just need dres, the Jool v and Eeloo

Eve on grand tour= you go to eve first with an disposable lander, option to top up tanks on Gilly before landing. 
A very low number of players has made Eve SSTO, might be as low as two or three. One did an suborbital capture who kind of count. 

Unless you are an expert with heavy ssto and see an SSTO taking 20 ton to Mun as child play don't bother.

[Gameslinx]

18 minutes ago, magnemoe said:

Eve on grand tour= you go to eve first with an disposable lander, option to top up tanks on Gilly before landing. 
A very low number of players has made Eve SSTO, might be as low as two or three. One did an suborbital capture who kind of count. 

Unless you are an expert with heavy ssto and see an SSTO taking 20 ton to Mun as child play don't bother.

I was thinking if I could visit eve first, top up as you said on Gilly, send down a small probe with a 1.25m shield and head back up with a nuke or two, and then tap the SSTO in orbit with it to count as a rendezvous, then leave it behind. Or tug it to Kerbin reentry and fill again on my mun.

But that's a lot more weight than I'd like to add for getting off Kerbin, but I can try!

[foamyesque]

I was working on an Eve SSTO plane, and had to turn on unbreakable joints because the thing was powered by, as I recall, five Mammoths, and would fall apart otherwise.
 

It is, most emphatically, not a simple task.

[Blaarkies]

6 hours ago, Gamel0rd1 said:

I was thinking if I could visit eve first, top up as you said on Gilly, send down a small probe with a 1.25m shield and head back up with a nuke or two, and then tap the SSTO in orbit with it to count as a rendezvous, then leave it behind. Or tug it to Kerbin reentry and fill again on my mun.

You could build a 5+ stage rocket with at least 8000m/s dv. Starting with a chair bolted to a probe core on a oscar fuel tank and ant engine, and tapering off to 3.75m fuel tank and vector engine. If you double/triple each stage relative to the upper stage, it gets really efficient dv, The whole craft weighs less than 60t. 

Just add a 10m heatshield and it should be fine...but it\s not a SSTO by any means 

[Vaporized Steel]

@Gamel0rd1

What is your motive for willing to do this?

Q:Is it a idea for cheap Eve manned missions? A: It won't be cheap. The very fuel cost would be more costly then a entire conventional asparagus staged rocket from sea level for 3 Kerbals. I know your idea is to refuel on the surface. But besides how long that will take it kinda tells you how much the vessel will cost/weigh even with dry mass only (it will be alot)

You can create a 2nd vessel with a LV-N tug at gilly and refuel the vessel once it gets in orbit. I am completely hypothesizing that you finish what your after (you won't because it's virtually impossible)

Not only that, but the whole cost of getting that vessel to Eve without it burning up in the atmosphere is probably more then if you were to send conventional asparagus staged rockets to each and every Biome on Eve seperately.

In a nutshell: Even if you manage this, it offers no benefit, other then boasting rights.

Even modded parts that work on the same stock propulsion methods that substitute LV-N, Rapier, Vector, mammoth designs and whatnot are simply rescales with different ISP values with a custom texture.
So it's the same technology really, and it won't make you a Eve SSTO. You'll need future propulsion techs for that to make it cost effective and make it reusable.

The most cost effective stock way to get to eve is to make a SSTO to carry 60-120tons in 2.5m - 3.75m form factor to LKO.  I do spaceplanes, then strap a heatshielded ascent rocket to it, take it to eve and get back in the SSTO you brought with you.
Anything else is you wasting alot of time.

Edited October 19, 2016 by Vaporized Steel

[Gameslinx]

2 hours ago, Vaporized Steel said:

@Gamel0rd1

What is your motive for willing to do this?

Q:Is it a idea for cheap Eve manned missions? A: It won't be cheap. The very fuel cost would be more costly then a entire conventional asparagus staged rocket from sea level for 3 Kerbals. I know your idea is to refuel on the surface. But besides how long that will take it kinda tells you how much the vessel will cost/weigh even with dry mass only (it will be alot)

You can create a 2nd vessel with a LV-N tug at gilly and refuel the vessel once it gets in orbit. I am completely hypothesizing that you finish what your after (you won't because it's virtually impossible)

Not only that, but the whole cost of getting that vessel to Eve without it burning up in the atmosphere is probably more then if you were to send conventional asparagus staged rockets to each and every Biome on Eve seperately.

In a nutshell: Even if you manage this, it offers no benefit, other then boasting rights.

Even modded parts that work on the same stock propulsion methods that substitute LV-N, Rapier, Vector, mammoth designs and whatnot are simply rescales with different ISP values with a custom texture.
So it's the same technology really, and it won't make you a Eve SSTO. You'll need future propulsion techs for that to make it cost effective and make it reusable.

The most cost effective stock way to get to eve is to make a SSTO to carry 60-120tons in 2.5m - 3.75m form factor to LKO.  I do spaceplanes, then strap a heatshielded ascent rocket to it, take it to eve and get back in the SSTO you brought with you.
Anything else is you wasting alot of time.

In answer to your first part - it's for 'boasting rights'. I want to do the grand tour mission in an SSTO. All I need to do now is take off from eve - I'm landed

 

[Plusck]

On 18/10/2016 at 0:35 AM, Gamel0rd1 said:

... send down a small probe with a 1.25m shield and head back up with a nuke or two ...

I didn't really want to reply to this bit since you have KER and I didn't think this was what you were actually planning to do... but you do realise, I hope, that you won't be able to get back to orbit with nukes. 

[Magzimum]

7 hours ago, Gamel0rd1 said:

In answer to your first part - it's for 'boasting rights'. I want to do the grand tour mission in an SSTO. All I need to do now is take off from eve - I'm landed

You already got a lot of recommendations from everyone. My 2 cents are: Go to the sandbox mode, and build yourself a Eve lander/launcher. Learn what it takes to get to Eve orbit if you can discard stages. Frankly, it is more than difficult enough for most players to land on Eve and take off again if they don't have to bring everything along until the end. 

Other than that, your best teacher is not in this thread: just try to build that "small probe with a 1.25m shield and a nuke or two", and get it to Eve with the alt-F12 option turned on (e.g. infinite fuel). Once you're safely landed on Eve, turn off the cheats, and see what works and what doesn't. We all have lots of ideas and dreams, and because KSP is such a good simulator (or because mother-nature is a b****), unfortunately most don't work. 

p.s. We are all curious to see pics of the ship you built! If you are off your phone, feel free to post some! 

 

Edited October 19, 2016 by Magzimum

[Zhetaan]

@Gamel0rd1:

If I recall correctly (my numbers are approximations; I don't have my calculations handy--and I'm sure that there are others who will be all too willing to correct my misinformation), SSTO ascent from Eve is only possible from altitudes over 6,000 m and even then only with an atmospheric (Kerbin rating, not Eve) ISP at or above 290.  Only three engines can do that, even in theory:  the Aerospike, the Vector, and the Mammoth, and the Aerospike cannot SSTO from Eve because it lacks the needed thrust.

On the other hand, it can be done:  it has been done.  What I do not know is whether such a craft can reach and return from all other bodies of the system in addition to Eve.  You would have to design your craft as an Eve SSTO first and then work from there, always building and designing within the limits of an Eve SSTO.  Unfortunately, those limits are beyond insane, as has been pointed out ... but still, it has been done, so maybe there is more to do.

Regardless, if you want to try this, you really ought to start with the Eve craft and go from there.  I'd suggest looking at the Eve SSTO Limbo Challenge for ideas on craft, and also to gain a better understanding of how to work this sort of a mission.

[Gameslinx]

32 minutes ago, Magzimum said:

You already got a lot of recommendations from everyone. My 2 cents are: Go to the sandbox mode, and build yourself a Eve lander/launcher. Learn what it takes to get to Eve orbit if you can discard stages. Frankly, it is more than difficult enough for most players to land on Eve and take off again if they don't have to bring everything along until the end. 

Other than that, your best teacher is not in this thread: just try to build that "small probe with a 1.25m shield and a nuke or two", and get it to Eve with the alt-F12 option turned on (e.g. infinite fuel). Once you're safely landed on Eve, turn off the cheats, and see what works and what doesn't. We all have lots of ideas and dreams, and because KSP is such a good simulator (or because mother-nature is a b****), unfortunately most don't work. 

p.s. We are all curious to see pics of the ship you built! If you are off your phone, feel free to post some! 

 

I'm on my phone again, BUT I live streamed the painstaking 8 hour mission spanning over 400 years.

Here's the link if you want to see the craft, I'll probably link the launch since a lot of the live stream was in map view. Here you go!

PS: Starts at *about* 3-5 minutes in when I launch. That's the best look at it. Other than that, the moon landings. Tylo got me good and proper, but I limped to Vall.

Also, I completed the challenge today! I did an Eve atmospheric flyby which counts towards the challenge which is nice!

https://www.twitch.tv/gameslinx/v/95308557

[Plusck]

Congratulations!

Still, seeing what you did to those LV-Ns, you might have been able to SSTO from Eve using them

Edited October 20, 2016 by Plusck

[AeroGav]

Late to this thread because I didn't want to sit up the next 4 days trying to do it.  It's my next big project, after finishing the interplanetary mk3.

In 1.05 I managed an Eve spaceplane that took off to orbit and it was quite small, for a craft that goes to orbit from Eve's surface. However it wasn't single stage.

I used a "Dart" aerospike at lower altitudes since it's got the second best atmo ISP in game (apart from the Vector, which is too heavy and too powerful for what we need).   At around 20km or so the atmosphere is as thin as on Kerbin at 10km, so jettison the dart (it was fed from some underwing ft800 tanks i also punched off) and proceeded on the nerv, which was now giving 650 isp and increasing.

Of course i needed hyperedit to actually put it there because it couldn't survive re-entry heat in 1.05.

Still, it's a mostly recoverable ship.   One dart and two ft800 wasn't an expensive way to get a kerbal off the surface, considering.