Eve SSTO lander (might be impossible) (edit: totally possible)

[M_Rat13]

Not really your typical challenge. No rankings, no competition, I just want to see if this is even possible. 

Now, I'm not going to be that harsh, you won't have to have a single SSTO from Kerbin to Eve and back. Granted, I'm not going to stop you, but physics certainly will. All you need to do is get an SSTO Lander from Eve orbit, down to the surface, and back up to orbit again, preferably with a space station in orbit to refuel it so it's fully reuseable. The lower you can land on Eve's surface, the more impressive.

Screenshots obviously for proof. So, off you go, let's see if anyone is good enough to pull this crazy stunt off, I've got my popcorn ready.

 

Edit: RIP

Edited March 24, 2019 by M_Rat13

[sevenperforce]

3 hours ago, M_Rat13 said:

Not really your typical challenge. No rankings, no competition, I just want to see if this is even possible. 

Now, I'm not going to be that harsh, you won't have to have a single SSTO from Kerbin to Eve and back. Granted, I'm not going to stop you, but physics certainly will. All you need to do is get an SSTO Lander from Eve orbit, down to the surface, and back up to orbit again, preferably with a space station in orbit to refuel it so it's fully reuseable. The lower you can land on Eve's surface, the more impressive.

Screenshots obviously for proof. So, off you go, let's see if anyone is good enough to pull this crazy stunt off, I've got my popcorn ready.

@Kergarin has pulled this off a couple of times. It's the holy grail of KSP. 

It can be done but not easily.

[M_Rat13]

Just now, sevenperforce said:

@Kergarin has pulled this off a couple of times. It's the holy grail of KSP. 

It can be done but not easily.

Proof?

If so, then I guess the next step is to have it launch from and return to Kerbin.

[sevenperforce]

Just now, M_Rat13 said:

Proof?

If so, then I guess the next step is to have it launch from and return to Kerbin.

Done, for the very first time, here:

 

Whistance is a beast.

[M_Rat13]

2 minutes ago, sevenperforce said:

Done, for the very first time, here:

 

Whistance is a beast.

I'm both annoyed and impressed.

Welp, there goes the fun of watching people tear their hair out....

Onto the next crazy stunt I can think of...

[Kergarin]

52 minutes ago, M_Rat13 said:

I'm both annoyed and impressed.

Welp, there goes the fun of watching people tear their hair out....

Onto the next crazy stunt I can think of...

There are already some challenge threads where you can reread how we have teared our hairs out 

[herbal space program]

2 hours ago, M_Rat13 said:

I'm both annoyed and impressed.

Welp, there goes the fun of watching people tear their hair out....

Onto the next crazy stunt I can think of...

I guess that pretty much proves what I was trying to say on the "If I ever get back from Eve"  thread before: If you want to get off Eve for as little dV as possible, you need a BIG ship.

Edited March 24, 2019 by herbal space program

[sevenperforce]

10 hours ago, M_Rat13 said:

I'm both annoyed and impressed.

Welp, there goes the fun of watching people tear their hair out....

Onto the next crazy stunt I can think of...

SSTO from Eve sea level is the next big stunt, I suppose. I have some ideas. A resorbable stock prop could do it, potentially. 

@Kergarin, have you ever had any success with a stock prop that can be detached and reattached indefinitely? Doing it with a Klaw is such a Kludge....

If you can land on Eve and refuel with ISRU, then you can land at SL, refuel, and fly to a higher takeoff point before repeating the process. That's straightforward enough. But actually doing it from SL without any further refueling is the real challenge. 

 

[Aeroboi]

I still have to devise the following and see whether it is possible.

But I had a idea myself to make a Eve sea level TSTO at the foot of the tallest equatorial mountain.
The idea is to make a first stage with a lot of thrust and use many parachutes and large landing gear as a cage around the first stage that would operate as a booster to get the 2nd stage to terminal velocity (200-300m/s) @ 7-8km.

The TSTO would stage 150meters below the top of the mountain and open all parachutes and the 2nd stage would fly on. The 1st stage would then land on the landing gear before the 2nd stage gets out of physics range so that it is landed when you want to switch back to it.

I think this is a good design because (A) you can use less thrust on the 2nd stage as it only requires power to stay at terminal velocity (it doesn't have to accelerate so no heavy engines needed)
(B) I think it could in fact have cargo capacity because the 2nd stage would be a 8km high 300m/s fast traveling rocket space plane that requires less then 1.0 TWR>

You then get to orbit, revert back to the 1st stage, drive (fly) it back to the foot of the mountain and refuel it with a ISRU module.
You then land the orbiter nearing the 1st stage and have a docking mechanism to reconnect and then repeat the process.

[sevenperforce]

37 minutes ago, Aeroboi said:

I still have to devise the following and see whether it is possible.

But I had a idea myself to make a Eve sea level TSTO at the foot of the tallest equatorial mountain.
The idea is to make a first stage with a lot of thrust and use many parachutes and large landing gear as a cage around the first stage that would operate as a booster to get the 2nd stage to terminal velocity (200-300m/s) @ 7-8km.

The TSTO would stage 150meters below the top of the mountain and open all parachutes and the 2nd stage would fly on. The 1st stage would then land on the landing gear before the 2nd stage gets out of physics range so that it is landed when you want to switch back to it.

I think this is a good design because (A) you can use less thrust on the 2nd stage as it only requires power to stay at terminal velocity (it doesn't have to accelerate so no heavy engines needed)
(B) I think it could in fact have cargo capacity because the 2nd stage would be a 8km high 300m/s fast traveling rocket space plane that requires less then 1.0 TWR>

You then get to orbit, revert back to the 1st stage, drive (fly) it back to the foot of the mountain and refuel it with a ISRU module.
You then land the orbiter nearing the 1st stage and have a docking mechanism to reconnect and then repeat the process.

I worked on this for a good while. It's doable.

[herbal space program]

1 hour ago, Aeroboi said:

...

The idea is to make a first stage with a lot of thrust and use many parachutes and large landing gear as a cage around the first stage that would operate as a booster to get the 2nd stage to terminal velocity (200-300m/s) @ 7-8km.

The TSTO would stage 150meters below the top of the mountain and open all parachutes and the 2nd stage would fly on. The 1st stage would then land on the landing gear before the 2nd stage gets out of physics range so that it is landed when you want to switch back to it.

I think this is a good design because (A) you can use less thrust on the 2nd stage as it only requires power to stay at terminal velocity (it doesn't have to accelerate so no heavy engines needed)
(B) I think it could in fact have cargo capacity because the 2nd stage would be a 8km high 300m/s fast traveling rocket space plane that requires less then 1.0 TWR>

You then get to orbit, revert back to the 1st stage, drive (fly) it back to the foot of the mountain and refuel it with a ISRU module.
You then land the orbiter nearing the 1st stage and have a docking mechanism to reconnect and then repeat the process.

I totally agree that if you were to give yourself a 2-300m/s leg-up taking off from the highest peak, you could do it with a much more normal-looking plane than the one we saw above.  I made a few two-stage Eve rockets just recently, and I would certainly agree that the key thing to do is pack as much TWR into the first stage as you can, then as you said drop most of your heaviest engines with the first stage.  In fact from 4000m I was recently able to make orbit  staging off nothing but 8 Vector engines, using the ship in the first image below.

The only comment I would have on what you outlined above is that you should probably just  forget about the idea of hitting TV before staging.  On the one hand, if you have a TWR significantly <1 you will lose speed quite rapidly, but on the other, TV at 7-8km for a large and pointy ship is actually much higher than 300 m/s, so you couldn't really do that anyway. I guess what that boils down to is that 200-300 m/s is probably a good target takeoff speed for your plane, but you won't be and actually won't want to be at TV when you take off. Anyway, I'm not sure what altitude you wanted to start from, but if you haven't got your spot picked out yet,  the HyperEdit coordinates in the second image below are for a big, flat spot at just over 4000m, with a nice ramp-like slope heading up towards the peak in question. Happy flying!

 

[Aeroboi]

18 minutes ago, herbal space program said:

I totally agree that if you were to give yourself a 2-300m/s leg-up taking off from the highest peak, you could do it with a much more normal-looking plane than the one we saw above.  I made a few two-stage Eve rockets just recently, and I would certainly agree that the key thing to do is pack as much TWR into the first stage as you can, then as you said drop most of your heaviest engines with the first stage.  In fact from 4000m I was recently able to make orbit  staging off nothing but 8 Vector engines, using the ship in the first image below.

The only comment I would have on what you outlined above is that you should probably just  forget about the idea of hitting TV before staging.  On the one hand, if you have a TWR significantly <1 you will lose speed quite rapidly, but on the other, TV at 7-8km for a large and pointy ship is actually much higher than 300 m/s, so you couldn't really do that anyway. I guess what that boils down to is that 200-300 m/s is probably a good target takeoff speed for your plane, but you won't be and actually won't want to be at TV when you take off. Anyway, I'm not sure what altitude you wanted to start from, but if you haven't got your spot picked out yet,  the HyperEdit coordinates in the second image below are for a big, flat spot at just over 4000m, with a nice ramp-like slope heading up towards the peak in question. Happy flying!

TV at 7-8km should indeed be higher then 200-300m/s but it was a arbitrary number out of the sleeve, I think up to 400m/s could be done with only mk3, big-s and mammoth and vector outer parts (i.e. a bradley whistance eve ssto type vessel, a.k.a. the way it should)
Anyway, the point of that design would most likely involve a jettison speed whereby the 1st stage can safely land. I'm sure it's theoretically possible to soft land it at the top using enough stopping power and precision when staging.

Since the 1st stage is reusable it could carry as much mammoths and vectors as launch budget could allow

[sevenperforce]

A promising architecture for a fully-reusable SL Eve TSTO would be to do parallel staging, like Energia+Polyus but with a Shuttle-C engine arrangement on the side-slung stage. That also fixes the difficulty with vertical integration, because the vehicles can be mated while erect, then fueled. The mated stack would launch from SL into a suborbital trajectory with crossfeed all the way up, then the upper stage would circularize before the lower stage performed the flyback and landing. You'd want support vehicles on the surface, but the whole thing would be fully reusable.

[herbal space program]

6 minutes ago, Aeroboi said:

TV at 7-8km should indeed be higher then 200-300m/s but it was a arbitrary number out of the sleeve, I think up to 400m/s could be done with only mk3, big-s and mammoth and vector outer parts (i.e. a bradley whistance eve ssto type vessel, a.k.a. the way it should)
Anyway, the point of that design would most likely involve a jettison speed whereby the 1st stage can safely land. I'm sure it's theoretically possible to soft land it at the top using enough stopping power and precision when staging.

Since the 1st stage is reusable it could carry as much mammoths and vectors as launch budget could allow

I think your safest bet would be to have it follow the second stage into the air for a short way and pull its chutes near the apex of its trajectory, ultimately landing on its wheels. If you put a probe core, batteries, panels, and some rover wheels on it, you could then drive it back to the launch site.

[Laie]

3 hours ago, Aeroboi said:

I think it could in fact have cargo capacity because the 2nd stage would be a 8km high 300m/s fast traveling rocket space plane that requires less then 1.0 TWR>

I've come to the belief that regardless of what's the payload, size, or eventual orbit, a first stage that doesn't get you to at least 300m/s is not worth having, and 450m/s and over seems to be worthwhile more often than not. Let me assure you that the second stage still needs a TWR >1 at the time of staging in order to maintain airspeed.

You're still going mostly up at that point... I haven't bothered to check, but by the time you're going 300m/s I estimate the horizontal distance traveled to be under 1km. I don't think it's possible to start in the plains and quickly land the first stage on top off a mountain, stock-only style, while everything is within physics range of each other.

Edited March 24, 2019 by Laie

[Kergarin]

14 hours ago, M_Rat13 said:

I'm both annoyed and impressed.

Welp, there goes the fun of watching people tear their hair out....

Onto the next crazy stunt I can think of...

 

I wrote a quick history of Eve SSTOs. Maybe it's good for some popcorn too 

 

3 hours ago, sevenperforce said:

SSTO from Eve sea level is the next big stunt, I suppose. I have some ideas. A resorbable stock prop could do it, potentially. 

@Kergarin, have you ever had any success with a stock prop that can be detached and reattached indefinitely? Doing it with a Klaw is such a Kludge....

 

I have to say, I have never really tried building props. 

But Eve sea level ascend has also already been done by Bradley. See the last link in the above linked history.

 

There actually was someone who has built an Eve TSTO recently. Sadly I can't remember who it was and can't find it actually. I guess it was pictures with no video. 

[herbal space program]

33 minutes ago, Laie said:

I've come to the belief that regardless of what's the payload, size, or eventual orbit, a first stage that doesn't get you to at least 300m/s is not worth having, and 450m/s and over seems to be worthwhile more often than not. Let me assure you that the second stage still needs a TWR >1 at the time of staging in order to maintain airspeed.

You're still going mostly up at that point... I haven't bothered to check, but by the time you're going 300m/s I estimate the horizontal distance traveled to be under 1km. I don't think it's possible to start in the plains and quickly land the first stage on top off a mountain, stock-only style, while everything is within physics range of each other.

For rockets I agree with everything you said 100%, but we're talking about a plane here and I don't really know what works best for that. I assume that the giant winged space caterpillar we just saw above, which is the first Eve SSTO I've seen, must have a TWR <1.

[M_Rat13]

37 minutes ago, herbal space program said:

For rockets I agree with everything you said 100%, but we're talking about a plane here and I don't really know what works best for that. I assume that the giant winged space caterpillar we just saw above, which is the first Eve SSTO I've seen, must have a TWR <1.

Something just clicked for me lol. When you said plane, I though of those electric powered prop planes people have built. On Eve, in atmosphere, it'd be perfect. How high can one of those go in Eve atmosphere? And how far from that is space? You might be able to get away with a cheap and dirty booster on an electric prop plane, if I'm on to something.

[Kergarin]

1 hour ago, herbal space program said:

For rockets I agree with everything you said 100%, but we're talking about a plane here and I don't really know what works best for that. I assume that the giant winged space caterpillar we just saw above, which is the first Eve SSTO I've seen, must have a TWR <1.

I guess @EvermoreAlpaca can tell.

26 minutes ago, M_Rat13 said:

Something just clicked for me lol. When you said plane, I though of those electric powered prop planes people have built. On Eve, in atmosphere, it'd be perfect. How high can one of those go in Eve atmosphere? And how far from that is space? You might be able to get away with a cheap and dirty booster on an electric prop plane, if I'm on to something.

He made it to 19.7km on props before igniting the rocket engines. It's also in the link above.

[M_Rat13]

3 minutes ago, Kergarin said:

I guess @EvermoreAlpaca can tell.

He made it to 19.7km on props before igniting the rocket engines. It's also in the link above.

And this is why you don't skip links....

That vector one seems perfect for an idea of mine, too.

[Kergarin]

16 minutes ago, M_Rat13 said:

And this is why you don't skip links....

That would have been devastating, as I just wrote it after reading this, taking me 5 hours