Teeniest Eve Ascent vehicle? Would it really work?

[Red Dwarf]

So I was watching Nassaults latest cinematic, and I was kind of surprised to see his Eve lander was as small as it was. I didn't think there was any way it was going to make the ascent. But then we got a shot of the business end.

That's a lot of sepetrons. The thrust to weight ratio on those things is insane, but I never considered them as a lifting stage. Has anyone tried this? If this actually works, I've got a new Eve mission to run!

[r_rolo1]

I also seen the video ( nassault makes really good ones, given the base material ), but I'm skeptical about that particular part. OK, separatrons have ridiculously high TWR, but they also have a dismal Isp ... maybe they are just there for the rule of cool. It is not that it would even be the first time in the same video that he makes something for the rule of cool ... or didn't you noticed that he was making the interplanetary burn in the wrong place and apparently ( can't be sure, but it definitely looks so ) in the wrong direction ?

[Red Dwarf]

I dunno about the interplanetary burn thing. You could do it the way he did and make it to Kerbin eventually (it would be inefficient as all hell, but you could still do it). Back on topic, I've seen sepetron-powered craft break atmo in a single stage. With that sort of oomph, but staged for maximum efficiency, would it work? I would test it myself, but my computer is currently a potato

[MadMooMan]

I admit I was thinking the same as you when I saw Nassault's video, although I didn't notice those sepatrons at the end . . .

I'll try recreate the lander and see how it goes.

[r_rolo1]

I dunno about the interplanetary burn thing. You could do it the way he did and make it to Kerbin eventually (it would be inefficient as all hell, but you could still do it). Back on topic, I've seen sepetron-powered craft break atmo in a single stage. With that sort of oomph, but staged for maximum efficiency, would it work? I would test it myself, but my computer is currently a potato

I was saying the burn from Kerbin ( sorry for my lack of clarity on that one ), that, unless he is coming from a clockwise LKO ( in that case, my question is why, for heavens sake ? , and also why to burn in that particular place ... ) it is being done in the wrong direction for the rule of cool of making the ship to be directed to the dark unknown ... and also made in a bad place even if it was in the right direction ...

Back on topic, the issue with Eve is that you don not necessarily want high TWR stuff ( because you will capped out in speed by drag for a lot of the way ... a thing I've seen a lot of people in youtube to forget when designing Eve missions. While you can muscle away your exit from Eve, it is far easier to not do so ), but you want engines with a tolerable Isp that is mostly unchanged by atmospheric pressure and , as a afterthough, that have decent TWR. The separatrons have a unchanging Isp with pressure , that is good , and a crazy high TWR, that is also a good thing, but their Isp is 100, that is bad in general and worse for a SRB ( their dry mass/fully loaded mass is in par with other SRB , btw ), so, while the proposed solution has some plausibility, it would need staging and probably fine tuning to even have a chance of working ....

Edited October 29, 2014 by r_rolo1

[Red Dwarf]

That was my plan! It looks like there's about fifty seps on the bottom of that thing. If you fired them in pairs, you would have 36 Kn of continuous thrust for minute and a half (someone please check my math). Could that be enough to get a capsule and some RCS fuel to orbit, like it's shown in the video? It probably wouldn't hurt to launch from Mount Eve-erest, too.

[MadMooMan]

Nope. I just did my best recreation of the lander and attempted to land, however the engines didn't have enough fuel + TWR to slow the lander down enough during descent to land safely.

Above that in the VAB the landing engines plus the sepatrons have a combined total of less that 2,000m/s dV, so if the lander landed its definitely not getting out of the atmosphere, even more so a stable orbit.

EDIT: Also, in the description of the video it says "Solar panels? Check! Heatshield? Check! Overpowered, super efficient takeoff/landing modded thruster engines? Check (go green)!"

However, If you managed to get the capsule,RCS and sepatrons to a high enough altitude it would probably get you to orbit.

Edited October 29, 2014 by MadMooMan

[Red Iron Crown]

That said, Eve ascent craft can be made very small, but I don't think sepatrons are the best technique to do so.

Edit: Watched the relevant part of the vid, that is not possible with stock parts/physics. Going by the description MadMooMan mentions I'd say the cfgs were edited to make it possible.

Edited October 29, 2014 by Red Iron Crown

[Epthelyn]

Overpowered, super efficient takeoff/landing modded thruster engines?

There's your answer, from the video description.