is an Eve SSTO rocket possible?

[Brainlord Mesomorph]

@GoSlash27 (not to thread-jack but were done here)

And what, in your opinion is a "practical goal" in KSP?

[Kergarin]

47 minutes ago, GoSlash27 said:

Fair 'nuff, but none of these strike me as "practical" goals. Well.. the *first* one does. I can see a reusable taxi if it can hit several biomes, but this doesn't do that.

A surface base could be served just as well (and more easily and flexibly) by a disposable lifter and "grand tour" missions are, by nature, impractical.

Not crapping on the concept, mind you. I've pursued many "impractical" goals myself. I'm just trying to understand the nature of it.

Best,
-Slashy

I can only say why I did it:

"not because it makes any sense, but because it's hard!" 

Well I think I wouldn't use this in career mode, but in fact this ship can reach any place on eve up to sea level, you just need to jump back to that hill before leaving and that's possible from almost everywhere in one launch.

This place could also be used as spaceport and you can travel to any place on eve using rovers and rocketplanes from there. A fixed position spaceport is not that unrealistic for colonizing a planet I think.

Also this thing can be further optimized as it got at least 10tons payload from there (maybe much more, never tested... but the remaining fuel in orbit didn't change by adding 3 seats, experiments and isru compared to the naked model).

My first SSTO was launched from 6.800 and I also have a 2 seats manned version for that. I think it can be tuned to launch from 6.500m, and that makes it able to land on much more sites.

I'm also have ideas how to land this thing without using fuel, so no isru is required on the ground.

 

So maybe it really is time for a new eve limbo contest, if this should end here? 

 

Edited August 27, 2016 by Kergarin

[Brainlord Mesomorph]

7 minutes ago, Kergarin said:

Well I think I wouldn't use this in career mode,

that's the whole idea.

If I'm going to pay to schelp something to Venus, I'd pay extra to land several times. Esp w/ a base.

EDIT b/c my 1/6 and 1/8 scale versions where looking like I could support them w/ my existing interplanetary tugs and tankers. If I am burning all the fuel all the way down then my 3/4 scale build should work,

Edited August 27, 2016 by Brainlord Mesomorph

[Kergarin]

3 minutes ago, Brainlord Mesomorph said:

that's the whole idea.

If I'm going to pay to schelp something to Venus, I'd pay extra to land several times. Esp w/ a base.

Have you eve said what exactly is your final goal or mission plan? Then I could rethink the design 

[fourfa]

Over in the stock electric aircraft thread, Azimech has an Eve plane.  Looks like a great way to get around Eve, to and from the 7K Base Spaceport.  If I was being sent to Eve, I'd sure as heck want to be stationed at the highest point above the hellish atmosphere too.  A long-term habitation on a mountaintop, ISRU fuel truck for the orbital SSTO, a fast rover, an electric airplane...  sounds fun to me!

[Kergarin]

1 minute ago, fourfa said:

Over in the stock electric aircraft thread, Azimech has an Eve plane.  Looks like a great way to get around Eve, to and from the 7K Base Spaceport.  If I was being sent to Eve, I'd sure as heck want to be stationed at the highest point above the hellish atmosphere too.  A long-term habitation on a mountaintop, ISRU fuel truck for the orbital SSTO, a fast rover, an electric airplane...  sounds fun to me!

Eve playground taxi 

[Brainlord Mesomorph]

32 minutes ago, Kergarin said:

Have you eve said what exactly is your final goal or mission plan? Then I could rethink the design 

I still don't have a "final" goal.  I was in the OP "toying w/ lander designs"

But as a shuttle for a hypothetical "7K Base" my goals would be small (-er than this), strip out the ISRU and generally multi-use, multi purpose.  (and no clipping)

How about 1 w/ a Mk3 payload bay (or 2, for symmetry) ? then you could put a landercan in there nice and safe, plus science, or light ISRU, or ... (a docking port and add payload later)

Some method of carrying other payload modules (docking ports) and dropping them by parachute near the landing site?? (i.e. base components)

It might only carry payload DOWN, (and kerbals up) that would be OK.

(edit: actually I just described the 3/4 scale version I was working on... I gave up on that one when I couldn't use parachutes)

Edited August 27, 2016 by Brainlord Mesomorph

[Brainlord Mesomorph]

@Kergarin Separate topic: I've been watching that video, you want to explain that throttle strategy to me?

I was under the impression that short burns at full throttle were best, that isn't what you're doing. Do you know something I don't? 

[foamyesque]

@GoSlash27: Because it's there!

[Kergarin]

15 minutes ago, Brainlord Mesomorph said:

@Kergarin Separate topic: I've been watching that video, you want to explain that throttle strategy to me?

I was under the impression that short burns at full throttle were best, that isn't what you're doing. Do you know something I don't? 

That might be right if you are in orbit and want to change it.

How would you do that in an atmosphere that always tries to kill you with friction heat while you try to manually hit a 100x100m landing site from 3200m/s without any guidance mods? 

If you do periodic burns on landing you will first get so slow that you don't make much use of atmospheric breaking and then the gravity quickly accelerates you so much that you will burn off if you don't do your next burn, you would have to do that repeatedly for the entire landing. I'm always keeping close to the maximum possible speed to maximize aerobraking while I'm focused on aiming at my launchsite.

On launch its the same thing, you will just burn off if you are to fast, but by cutting off throttle you quickly lose a lot of speed, and that doesn't seem to be efficient to have a mix of accelerating and braking on a gravity turn. Once out of the atmosphere, how do you want to do full throttle precision maneuvers with a few hundred units of fuel on 8 mammoth? 

[foamyesque]

1 hour ago, Kergarin said:

On launch its the same thing, you will just burn off if you are to fast, but by cutting off throttle you quickly lose a lot of speed, and that doesn't seem to be efficient to have a mix of accelerating and braking on a gravity turn. Once out of the atmosphere, how do you want to do full throttle precision maneuvers with a few hundred units of fuel on 8 mammoth? 

I'm looking at using action-groups to disable the Mammoths and finish up on radially-attached Vectors, but there's a TWR penalty to using Vectors over the Mammoth. =/

[GoSlash27]

2 hours ago, Brainlord Mesomorph said:

If I'm going to pay to schelp something to Venus, I'd pay extra to land several times. Esp w/ a base.

That's the part I'm not getting. What purpose would these multiple landings at the same spot serve?

3 hours ago, Kergarin said:

this ship can reach any place on eve up to sea level, you just need to jump back to that hill before leaving and that's possible from almost everywhere in one launch.

This makes sense. You could even use it as a sort of biome hopper... but that's liable to be a bit slow and risky.

Thanks,
-Slashy

[Kergarin]

1 hour ago, foamyesque said:

I'm looking at using action-groups to disable the Mammoths and finish up on radially-attached Vectors, but there's a TWR penalty to using Vectors over the Mammoth. =/

Does it really make a difference in the game if you use one engine on full throttle instead of two on half throttle? 

[foamyesque]

4 minutes ago, Kergarin said:

Does it really make a difference in the game if you use one engine on full throttle instead of two on half throttle? 

 

It's not any more fuel efficient, assuming the engines have the same Isps, but it gives me much finer control over my throttle for the final manouvering. I could achieve the same effect by thrust-limiting the mammoths after I got to near-orbit, but that's a pain to do mid-flight. In a hypothetical 1 mammoth + 1 vector cluster (what I used on my previous design -- still working on the next iteration), deactivating the Mammoths means that my throttle has five times the precision, but only one fifth the maximum thrust.

Edited August 27, 2016 by foamyesque

[fourfa]

Now that you can pin menus, it's not so bad to change throttle limits on the fly

[Kergarin]

This is not really an Eve SSTO, but it includes another way to get to and from Eve completely reusable, if someone is still interested