is an Eve SSTO rocket possible?

[NSEP]

16 minutes ago, Firemetal said:

Good luck. 

(Contains HyperEdit)

[Firemetal]

Just now, NSEP said:

(Contains HyperEdit)

Obviously. I use Hyperedit to test all my Eve landers.

[NSEP]

1 hour ago, Firemetal said:

Obviously. I use Hyperedit to test all my Eve landers.

Ok, i will try in 24 hours, this is my last day of my vacation soo...

[W. Kerman]

20 hours ago, Firemetal said:

A vertical SSTO. Ask @NSEP. He specializes in them.  

Made one of these for the k prize challenge instead of reading those pesky, "it has to be a space plane" rules. 

[RA3236]

Didnt @Kuzzter do it in his Eve Order 0 novel? Im fairly certain that was 1.0.

[NSEP]

36 minutes ago, W. Kerman said:

Made one of these for the k prize challenge instead of reading those pesky, "it has to be a space plane" rules. 

Alot if people confuse spaceplanes with SSTO's, while SSTO's dont have to be planes. The feels bro.

[Firemetal]

2 minutes ago, NSEP said:

Alot if people confuse spaceplanes with SSTO's, while SSTO's dont have to be planes. The feels bro.

That is true. However SSTOs and planes go together as planes are also single stage.

[FyunchClick]

46 minutes ago, RA3236 said:

Didnt @Kuzzter do it in his Eve Order 0 novel? Im fairly certain that was 1.0.

Well, @Kuzzter left a lot of bits behind, so that disqualifies the M7 from the first S of SSTO.

[Brainlord Mesomorph]

OK:

This bad boy has 2600 m/s dV with the LFO engines, and 4600 m/s on nukes, that equals 7200.

Not quite 8k,  But assuming we land in the mountains, and we don't actually have to make orbit, just a sub-orbital rendezvous with the sister ship. it might be just enough.The question is: will the Mammoth get the thing to a high enough altitude for the nukes to actually work.

Still have to figure out the parachutes and design that sister ship.

Edited August 15, 2016 by Brainlord Mesomorph

[Terwin]

On 8/13/2016 at 7:13 PM, foamyesque said:

 

Eve sea-level SSTO is, in fact, outright impossible. Naked tanks don't give enough deltaV, even before you start accounting for things like engines and TWR. SSTOing from a mountaintop, like @astrobond did, is only just within the reach of possibility; it needs roughly ~5500m/s of high TWR thrust, which a Mammoth or Vector can manage.

If you have >1.0 TWR at Eve sea level, and ISRU, you can land a sea level, refuel, fly somewhere higher, refuel, etc, until you launch for orbit from Eve's highest peak.

Would this still count as SSTO?  No staging events happen...

[magnemoe]

43 minutes ago, Terwin said:

If you have >1.0 TWR at Eve sea level, and ISRU, you can land a sea level, refuel, fly somewhere higher, refuel, etc, until you launch for orbit from Eve's highest peak.

Would this still count as SSTO?  No staging events happen...

Still an SSTO obvious, actually more than an SSTO as you could jump around. Simlar to the Laythe and Tylo SSTO I uses now. it mapped all biomes no Tylo and Laythe in one go jumping around before going to orbit. 
Problem is that you would have to carry all the extra mass making this far harder.

[NightshineRecorralis]

Couldn't you just abuse the isp on engines? Like have both aerospikes and swivels, but cut out the swivels once the isp of the aerospikes over take it, and maybe have nukes once they are usable? I have a Kerbin SSTO that works on this principle, gets to orbit with 2200m/s+ to spare.

Edited August 15, 2016 by NightshineRecorralis

[foamyesque]

3 hours ago, Terwin said:

If you have >1.0 TWR at Eve sea level, and ISRU, you can land a sea level, refuel, fly somewhere higher, refuel, etc, until you launch for orbit from Eve's highest peak.

Would this still count as SSTO?  No staging events happen...

Not really a SSTO from sea level any more than I'd count being able to drive to and from with a rover as it.

With a plane layout, you wouldn't need a TWR > 1.0 ASL, either; I actually have an Eve mission that takes that precise approach, but it's ASL TWR is around 0.5 and it's a three-stage setup. The sole point of one of the stages is to substitute for a mountaintop launch and get the ship to climb to around 7-8km up (and some vertical velocity, but it's mostly altitude); beyond that, it's a mammoth, pushing a poodle-powered upper stage that is also a Kerbin-re-entry shuttle for 4 Kerbs.

Edited August 15, 2016 by foamyesque

[suicidejunkie]

12 minutes ago, foamyesque said:

Not really a SSTO from sea level any more than I'd count being able to drive to and from with a rover as it.

With a plane layout, you wouldn't need a TWR > 1.0 ASL, either; I actually have an Eve mission that takes that precise approach, but it's ASL TWR is around 0.5 and it's a three-stage setup. The sole point of one of the stages is to substitute for a mountaintop launch and get the ship to climb to around 7-8km up (and some vertical velocity, but it's mostly altitude); beyond that, it's a mammoth, pushing a poodle-powered upper stage that is also a Kerbin-re-entry shuttle for 4 Kerbs.

SSTO doesn't need to be SLaunchTO.

There's one stage, nothing falls off.  SSTAnywhere is perfectly legit to refuel on Minmus.  The mountains are the Minmus of Eve's surface, like Gilly is the Minmus of Eve's orbit.

[Stratzenblitz75]

10 hours ago, Brainlord Mesomorph said:

OK:

 

This bad boy has 2600 m/s dV with the LFO engines, and 4600 m/s on nukes, that equals 7200.

Not quite 8k,  But assuming we land in the mountains, and we don't actually have to make orbit, just a sub-orbital rendezvous with the sister ship. it might be just enough.The question is: will the Mammoth get the thing to a high enough altitude for the nukes to actually work.

Still have to figure out the parachutes and design that sister ship.

 

4 hours ago, NightshineRecorralis said:

Couldn't you just abuse the isp on engines? Like have both aerospikes and swivels, but cut out the swivels once the isp of the aerospikes over take it, and maybe have nukes once they are usable? I have a Kerbin SSTO that works on this principle, gets to orbit with 2200m/s+ to spare.

 

The problem with NERVAs is that their TWR is simply too low. Eve's gravity is brutal, and you really need high TWR throughout the entire flight to make it into orbit. Plus, NERVAs add a TON of mass to your ship, thus reducing the effectiveness of your high TWR mammoth engine. Same deal with aerospikes: too heavy for too little thrust. Plus, the aerospikes barely provide an improvement over the vector, so you are probably better off just using only vectors.

Another problem with using Aerospikes/NERVAs is that they force you to use more attachment nodes, and thus, add more drag to your ship. Since Eve's atmosphere is so thick, this is actually a big problem.

All in all, you are just better off using only mammoths or vectors. They have the highest TWRs in the game, and they have great ISPs at both sea level and in a Vacuum. Perfect for an Eve launch vehicle. 

Edited August 15, 2016 by Stratzenblitz75
Vector/Swivel mixup

[Brainlord Mesomorph]

29 minutes ago, Stratzenblitz75 said:

All in all, you are just better off using only mammoths or swivels. They have the highest TWRs in the game, and they have great ISPs at both sea level and in a Vacuum. Perfect for an Eve launch vehicle. 

wait-a-minute 

doesn't YOUR Eve-Infinity thing use nukes???

edit- oh sorry that's the sister ship

Edited August 15, 2016 by Brainlord Mesomorph

[foamyesque]

31 minutes ago, Stratzenblitz75 said:

All in all, you are just better off using only mammoths or swivels. They have the highest TWRs in the game, and they have great ISPs at both sea level and in a Vacuum. Perfect for an Eve launch vehicle. 

The Swivel? It's beaten on both TWR and atmospheric Isp by a bunch of engines. The Reliant, the Vector, the Mainsail, the Skipper, the Dart...

[Stratzenblitz75]

1 minute ago, foamyesque said:

The Swivel? It's beaten on both TWR and atmospheric Isp by a bunch of engines. The Reliant, the Vector, the Mainsail, the Skipper, the Dart...

Oh, S***, sorry my mistake. I meant to say Vector. Getting my engines mixed up 

[septemberWaves]

I'm currently adapting a two-stage Eve rocket to work with stock parts (I have recently suffered a setback in computing power and now I can only play the game in stock). It should be able to transport 18 kerbals to most prograde Eve orbits from sea level (though why one might need an inclination greater than that of Gilly is beyond me), and the upper stage is reusable (and is adapted from a vehicle that can SSTO from anywhere other than Eve). Getting that in two stages was difficult enough. One stage is almost certainly beyond what I am capable of, but that is primarily because of heat shielding and the fact that it's impossible to protect the engines on descent without adding a new heat shield (and since I have to make that journey anyway I just send a new ascent stage and refuel the reusable stage).

EDIT

The scale of my ascent stage means that it may be possible for me to create a cargo module that can transport small payloads (such as ore tanks for contracts) into Eve orbit from its surface. Whether or not I can achieve that is debatable, but there will certainly be an attempt.

EDIT 2

I'd like to point out that the current design uses several vector engines on the ascent stage, and aerospikes for the upper stage. I'm still playing around with the numbers, but it's most likely going to end up being 18 or 19 vectors and 6 aerospikes (that being said, adapting this vessel to use stock parts may pose some further difficulties when in testing that lead to the need for additional ascent stage engines).

Edited August 16, 2016 by eloquentJane

[Brainlord Mesomorph]

just an update:

That thing can't survive reentry on KERBIN, 

so - back to the drawing board....

[Sharpy]

Well, from sea level it might be doable... if you drive to the mountaintop on wheels

Personally, I'd consider aerospikes. Sluggish airborne ascent to mountaintop altitude on wings, then going on some power-efficient engines once air gets thin enough. On lower altitudes you need really little lifting surface and not much speed at all to fly, your problem is thrust of most engines drops to zilch, but Aerospike is especially immune to that problem, even more so than Twin Boar and Mammoth, and weighs a fraction of their mass - plus you don't need excessive thrust to remain in a climbing flight.

I wish there was a nuclear jet engine in the game. NERVA really doesn't care about the type of propellant - hydrogen grants it the highest ISp, and as result best wet:dry mass ratio, but it can run on pretty much any propellant, including inert gasses of any atmosphere, and in air-breathing mode it could keep flying in atmosphere as long as the nuclear fuel lasts (and while hydrogen gives it best ISp, heavier propellants provide higher thrust.) On a related note, I wish for a mod that would allow switching the nukes to Xenon, providing much better thrust at cost of ISp.

[foamyesque]

Actually, the curve for Mammoths and Vectors is actually better for Eve sea-level than aerospikes are. Aerospikes don't overtake them on Isp until around 9km, I believe.

[fourfa]

4 hours ago, foamyesque said:

Actually, the curve for Mammoths and Vectors is actually better for Eve sea-level than aerospikes are. Aerospikes don't overtake them on Isp until around 9km, I believe.

Not quite - the aerospike is ahead of Vector/Mammoth at sea level and in vacuum, but Vector has a brief ISP spike around 9km. 

[eddiew]

41 minutes ago, fourfa said:

Not quite - the aerospike is ahead of Vector/Mammoth at sea level and in vacuum, but Vector has a brief ISP spike around 9km. 

Excellent chart! Where did you find this little gem?  

[fourfa]

Made it myself after much exploding in Eve testing in 1.0.4 and 1.0.5. This captures the atmospheric changes that came in with 1.0.5., and AFAIK nothing has changed about Eve since then

Edited August 16, 2016 by fourfa