DAL59

SSTO Eve no docking or refueling

Recommended Posts

So, it has been concluded that a Tylo SSTO is probably impossible.  What might be possible, though, is an Eve SSTO.  Why?  You can use airbreathers for the Kerbin ascent, ions for the transits, and aerobraking for landing on Kerbin and Eve.  You can also save fuel by horizontal takeoff on Eve, or have a spaceplane with stock props.  Can it be done?

@Matt Lowne @EvermoreAlpaca @sevenperforce @sdj64 @Andetch @JacobJHC @Lirtosiast

Share this post


Link to post
Share on other sites
Just now, DAL59 said:

So, it has been concluded that a Tylo SSTO is probably impossible.  What might be possible, though, is an Eve SSTO.  Why?  You can use airbreathers for the Kerbin ascent, ions for the transits, and aerobraking for landing on Kerbin and Eve.  You can also save fuel by horizontal takeoff on Eve, or have a spaceplane with stock props.  Can it be done?

@Matt Lowne @EvermoreAlpaca @sevenperforce @sdj64 @Andetch @JacobJHC @Lirtosiast

While that might be doable with propellers I think that @EvermoreAlpaca is the only person here out of any of us who could actually fly a mission that efficiently.

Also @sdj64 might have made a Tylo SSTO but it never flew to Tylo. 

Share this post


Link to post
Share on other sites
1 hour ago, JacobJHC said:

I think that @EvermoreAlpaca is the only person here out of any of us who could actually fly a mission that efficiently.

I mean, someone else could build it and share the craft file with him.  

Share this post


Link to post
Share on other sites

Don't rename this challenge, just make a new one

Share this post


Link to post
Share on other sites

@DAL59 you need to get the definition of SSTO right in your head. 

SSTO = Single Stage to Orbit. Implied is LKO.  Although, if you are on Eve surface then Low Eve Orbit would be implied. Therefore staging (and dropping parts) would be allowed en-route to Eve from LKO, and then again staging from LEO back to Kerbin. 

Some things I have seen on the forum would have some application for this, for example there is someone I saw with a nice SSTO launcher from Eve, but once out of the atmosphere the craft split up, with the launcher heading back to land in the mountains of Eve, and the craft able to go anywhere. 

However, it is generally accepted that anything leaving Eve surface as a SSTO will need to refuel in LEO, maybe have enough fuel to get to Gilly but generally speaking it won't have fuel for anything much. 

Also, using air breathing engines for Kerbin ascent would be a waste because what you gain in Kerbin's soup atmosphere, you would lose by dragging dead weight all the way to Eve and back (unless of course you staged after reaching LEO and dropped the air breather engines). 

Share this post


Link to post
Share on other sites
On 7/1/2018 at 11:48 AM, Andetch said:

SSTO = Single Stage to Orbit. Implied is LKO.  Although, if you are on Eve surface then Low Eve Orbit would be implied. Therefore staging (and dropping parts) would be allowed en-route to Eve from LKO, and then again staging from LEO back to Kerbin. 

If that's the criteria then Stratzenblitz75 has already done this.

 

 

Also if someone claims to have a Tylo SSTO working I'd assume liar until a video is posted proving otherwise, or at the very least pictures. I'm pretty certain that Tylo SSTO is mathematically impossible without refuelling. The only ways are either a) separate Tylo Lander b) IRSU. I and many others have done those missions but there's a reason why nobody has done the "true tylo SSTO". 

 

Happy to be proven otherwise but I don't see how it would be possible in stock.

Share this post


Link to post
Share on other sites

Edit: A Tylo SSTO lander is doable, you only need about 4000ms of dV and a TWR above 1, a single SSTO launched from Kerbin round trip I am not sure anyone has done.

Edited by selfish_meme
Misunderstood statement

Share this post


Link to post
Share on other sites
21 hours ago, Matt Lowne said:

If that's the criteria then Stratzenblitz75 has already done this.

 

 

Also if someone claims to have a Tylo SSTO working I'd assume liar until a video is posted proving otherwise, or at the very least pictures. I'm pretty certain that Tylo SSTO is mathematically impossible without refuelling. The only ways are either a) separate Tylo Lander b) IRSU. I and many others have done those missions but there's a reason why nobody has done the "true tylo SSTO". 

 

Happy to be proven otherwise but I don't see how it would be possible in stock.

Wow! KSP Celebrity quoted me! It almost makes me feel like I am special...... Almost.

I think getting to Tylo is possible but the return certainly is not, unless using a crazy Scott Manly gyro drive system. But what would I know. I managed to put a lander onto Tylo once, ever so slightly misjudged the landing and blew the engine on touchdown. Not that there was enough fuel to leave Tylo again anyway. 

I think the posted mission is certainly impressive, but not what the OP was meaning by SSTO. I think, based on previous interaction, that Dal is looking for a single craft that stays intact and is capable of going from Kerbin's surface, to Eve's surface, and then back to Kerbin in one journey with no refueling or staging anywhere..... Which is just about as likely as myself getting into a loving relationship with [INSERT HOT CELEBRITY HERE].  

EDIT: Also, I just had this afterthought - in the video he doesn't do a SSTO from Eve as he used a tug to finish off the orbital insertion of the lander. 

Edited by Andetch

Share this post


Link to post
Share on other sites

I think what you are imagining is completely impossible.  Nobody has even made an Eve SSTO with refueling that can operate entirely independently (i.e. make it to Gilly to refuel after Eve takeoff without using a dockable fuel container left in low Eve orbit).

You should probably ping @Kergarin too since he is the expert in Eve SSTOs.  This video shows his Eve SSTO which uses a dockable fuel container.  It was done in version 1.2.2 but I didn't see any atmosphere changes since then, looking through the version history.

https://www.youtube.com/watch?v=iIuSCWxPZm4

 

Share this post


Link to post
Share on other sites

I've built an SSTO for use at Eve. That doesn't count for this challenge, but some may find it curious at least. Here's the Kerbal X link.

I'm thinking of naming the craft Razorforce Seven, in honour of the naysayer who told me I'd never make it off Eve's surface on such a contraption.

Is it possible to adapt it for use from Kerbin to Eve? Maybe one could fit 2.5 tonnes of ISRU in that cargo bay, but it would only have 350 m/s in LEO; not enough to go anywhere but back to the surface.

Edited by Gordon Fecyk
Added Kerbal X link

Share this post


Link to post
Share on other sites
1 hour ago, Gordon Fecyk said:

I'm thinking of naming the craft Razorforce Seven, in honour of the naysayer who told me I'd never make it off Eve's surface on such a contraption.

This may be the best thing I've ever read on this forum.

Share this post


Link to post
Share on other sites

The one issue I see with @Gordon Fecyk's very impressive Eve SSTO is the atmosphere mod he states he is using. 

To my knowledge in stock ksp a)air breathing engines do not function on Eve and b) Eve atmosphere is 100km, not 60km. 

Other than that, I have to say it is a cool looking ship, and I definitely wanna play with the probe!

Also, I wanna put KSC onto other planets! Which mod did you use?

Edited by Andetch

Share this post


Link to post
Share on other sites

@Andetch You're looking at Alien Space Programs, which moves the KSC to other worlds in the stock system. It happens to use OhioBob's Realistic Atmospheres, hence the 55 km ceiling. Though I suspect the Stock atmosphere may be easier for this plane since I could climb much higher at slower speeds, and re-entry could be easier with a slower orbit speed at 90 km up.

Those jets breathe hydrocarbons theorized to be in Eve's air, evaporated from the Explodium Sea, hence "Explodium Breathing Engines." They burn oxidizer. I went to considerable effort to make the oxidizer usage and thrust somewhat realistic and comparable to the Stock jets; the repository has a Wiki that goes over the math. Oxidizer usage is about 2.2x that of liquid fuel in the Stock jets.

Share this post


Link to post
Share on other sites

@Gordon Fecyk let me make it clear - I love your designs and videos. I am a big fan, and i learn stuff from them too!

You're even due a badge from an old challenge of mine that I forgot about due to an issue with my computer (so if you remember the really annoying to handle SSTO help yourself to the badge) ;)

I think I might have a go in your SSTO on my quasi-stock game, and I will replace the air breather with similar thrust lfo engines. Will be interesting to see how it performs - only one way to tell how it will handle :)

Edited by Andetch

Share this post


Link to post
Share on other sites
1 minute ago, Andetch said:

 let me make it clear - I love your designs and videos.

No worries. The KSP community is a very pedantic one though, so I want to make sure that anything that 'looks weird' has a reasonable explanation.

Share this post


Link to post
Share on other sites
On 7/3/2018 at 11:22 PM, sdj64 said:

I think what you are imagining is completely impossible.  Nobody has even made an Eve SSTO with refueling that can operate entirely independently (i.e. make it to Gilly to refuel after Eve takeoff without using a dockable fuel container left in low Eve orbit).

You should probably ping @Kergarin too since he is the expert in Eve SSTOs.  This video shows his Eve SSTO which uses a dockable fuel container.  It was done in version 1.2.2 but I didn't see any atmosphere changes since then, looking through the version history.

https://www.youtube.com/watch?v=iIuSCWxPZm4

 

Thanks for mentioning me!

Yes this should still work. While I would not call it SSTO. It uses and adapted version of @Stratzenblitz75's suborbital docking.

My real Eve SSTO lander doesn't work anymore. https://youtu.be/C6ChB20KshE

It was for 1.1.3 and the atmosphere was changed in 1.2 to have even higher pressure at low levels.

SSTO from the highest point is still possible, but payload and upscaling doesn't work as before. https://youtu.be/DuEwQHHZpB0

 

I was pretty happy recently to see the creator of the first ever Eve SSTO back. @astrobond has just build the smallest Eve SSTO I have ever seen. 

really sad this doesn't have more views, while people who have clickbait video titles about Eve SSTO or everywhere SSTO have hundreds of thousands views...

 

Back to the op: this is not possible in pure stock. If you launch from Eve's highest mountain, you can barely make it a few thousand KM above the atmosphere. Not any further. And that is with a craft that has 100% full fuel tanks at launch from Eve and virtually no payload.

I have seen someone who moved an asteroid to low Eve orbit, to refuel his craft there. But this makes this craft dependent on moving asteroids there, what is a cool idea, but not really a difference to moving fuel tanks there, as both would be refuelling, which you don't want, if I understand wo right.

 

I sadly did not have the time, to test how the making history parts work on Eve. Maybe there are some advantages by using the larger fuel tanks or so. But I don't think this will get us to Gilly or anywhere close to completing this challenge.

Edited by Kergarin

Share this post


Link to post
Share on other sites

Just tried the Stock Eve atmosphere with the Razorforce Seven. As I figured I was able to get higher on the Zephyrus turbofans, but I ended up using more oxidizer on the speed run. Managed a sub-orbital flight with AP at 92 km and PE just over 86 km.

I think with either another +2000 OX, or -1000 LF for a lower mass, I can make Eve orbit in the Stock atmosphere with this design. Maybe I could replace the single Big-OX wings with several Big-OX strakes to get more OX for the same wing mass and surface area, and end up with something that looks like AeroGav's Kondor.

The flight plan is similar though: Slow-climb on the turbofans until atmosphere density is about 2.5 kg/m3 (per FAR's display), then zoom-climb on the Beelzebub ramjets and level off at just above 1 kg/m3. Speed-run as much as you can and ignite the Vector rockets at maybe 35 km up or so, when ramjet thrust drops below 175 kN. 

Share this post


Link to post
Share on other sites

I am 100% confident that an Eve SSTO, even if possible, would have such razor-thin margins that anything extra would tank it.

So, no, you can't make it from Kerbin to Eve and back without staging. Not to say that you can't reuse everything. You can. But it has to stage or dock or refuel at some point.

Share this post


Link to post
Share on other sites
On 7/3/2018 at 10:22 PM, sdj64 said:

I think what you are imagining is completely impossible.  Nobody has even made an Eve SSTO with refueling that can operate entirely independently (i.e. make it to Gilly to refuel after Eve takeoff without using a dockable fuel container left in low Eve orbit).

Incorrect, good sir.

https://www.youtube.com/watch?v=_-pctls27b0

Share this post


Link to post
Share on other sites
36 minutes ago, Matt Lowne said:

Yes, that's exactly the video I was talking about :)

On 7/8/2018 at 1:03 PM, Kergarin said:

...

I have seen someone who moved an asteroid to low Eve orbit, to refuel his craft there. But this makes this craft dependent on moving asteroids there, what is a cool idea, but not really a difference to moving fuel tanks there, as both would be refuelling, which you don't want, if I understand wo right.

...

But sadly - like my own SSTO - this won't work in Eves new atmosphere :(

Share this post


Link to post
Share on other sites

To get from LEO to Gilly you only need another 1600 m/s. 'Only.' I wonder if Thrimm's SSTO math would extend that far from Eve's surface.

Thrimm's Kerbin SSTOs use a logic of getting to 1200 m/s air speed and then have enough rocket delta-v at a TWR around 1 to go where you planned to go. I had to adjust for an airspeed of 900-1000 m/s for Eve but still managed a TWR > 1 at least at rocket ignition (Vectors plus 'ramjet' assist). 3.2 km/s atmospheric dV at 18 km up (RA) or 30 km up (Stock) and 900 m/s airspeed gets me to LEO. I wonder if I can raise that to 4.6 km/s somehow.

Share this post


Link to post
Share on other sites
On 7/17/2018 at 9:10 PM, Gordon Fecyk said:

To get from LEO to Gilly you only need another 1600 m/s. 'Only.' I wonder if Thrimm's SSTO math would extend that far from Eve's surface.

Thrimm's Kerbin SSTOs use a logic of getting to 1200 m/s air speed and then have enough rocket delta-v at a TWR around 1 to go where you planned to go. I had to adjust for an airspeed of 900-1000 m/s for Eve but still managed a TWR > 1 at least at rocket ignition (Vectors plus 'ramjet' assist). 3.2 km/s atmospheric dV at 18 km up (RA) or 30 km up (Stock) and 900 m/s airspeed gets me to LEO. I wonder if I can raise that to 4.6 km/s somehow.

Ion engines for the interplanetary.

Share this post


Link to post
Share on other sites

Nertea's Near Future Aeronautics pack has a nuclear jet engine that might make an Eve SSTO easier. On the one hand, it feels a bit cheaty because like the stock Nerv, it doesn't actually consume any nuclear fuel, but instead of LF for propulsion mass it uses atmospheric gases, which effectively means it uses no internal resources. But it's very heavy, has slow throttle response, and doesn't work in a vacuum (I think there's a multimode version though).

 

Share this post


Link to post
Share on other sites
On 7/17/2018 at 5:14 PM, Kergarin said:

Yes, that's exactly the video I was talking about :)

But sadly - like my own SSTO - this won't work in Eves new atmosphere :(

Months behind on this response, but this video WAS in the new atmosphere.

And yes, leaving an asteroid in orbit is roughly the same concept of leaving a fuel tank there, but I would like to think it was a fun loophole.

As to making it to Gilly from Eve on one stage, without refueling, it isn't possible unless a glitch is used.  Or some kind of extreme lateral thinking solution.  Using the conventional approach, I haven't been able to manage more than a few hundred m/s dV from LEO.

Edited by EvermoreAlpaca

Share this post


Link to post
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.