Share your reusable Eve surface to orbit shuttles here

[KerikBalm]

So far I don't have any SSTOs, but I do have reusable 2 stage designs.

Single kerbal shuttle:

Spoiler

Only change needed is the orbiter needs a shielded docking port, and thus must launch seperately and connect with the 1st stage plane (the dockingport heights line up on the ground)

And then a roll on-roll of cargo hauler which can lift 18 tons... thinking about making a seperate fuel hauling variant that ditched the cargobays (7 tons) to allow it to lift more fuel.

Spoiler

Again, the orbiter needs its docking port changed. The carrier also needs a long time for its RTGs to recharge the batteries...

But these designs can boost the orbiter up, the orbiter can reach orbit before the carrier falls back into the atmosphere, and the carrier can survive reentry and fly on EC back to a fueling base.

The orbiter can glide back to near the landing site, and the carrier can dock with it on the ground. They can then fly together back to a fueling site, and be ready to go again.

 

I would really like to see SSTOs though

[OHara]

Before the Breaking Ground add-on, I was happiest with a two-stage shuttle that depends on a surface base for refueling.  The Mk3 booster portion is shown at left at the refueling/science base, with the local exploration aircraft in between.  The 4-kerbal Mk2 upper portion is shown at right docked to the orbital station.

This 2-stage shuttle needs to start about 7400 meters above sea level, so the colony is restricted to on of Eve's high points.  The shuttle launch to orbit (link) and glide back to the peak is just difficult enough to be fun --- difficult enough that I didn't want to return the shuttle to the base just to make a screenshot here.

Be sure to see Kergarin's thread,

 

[KerikBalm]

Thats a cool and compact vehicle. Looks like your 1st stage goes pretty much straight up. What is the minimum altitude needed for launch?

What do you do if there's no ore above that altitude?

For myself, I haven't tried launching from sea level just yet, I think I launch from around 1km... which only matters because my initial climb is currently limited by battery power. I get to just under 11km before the batteries have nearly run out and I need to fire the rockets.

I also cliumb at about 60 degrees, so that the orbiter needs less dV, this means that the 1st stage cannot land where it launched from. That's why I used a lot of batteries rather than fuel cells - so it can recharge on the ground, then fly a long distance before needing to recharge again. With fuel cells, if I land with no reserve fuel, it won't make it back to the launch site without many, many stops (which is a problem if one needs to cross oceans). I could try to give it enough fuel cells to sustain flight, and a reserve fuel tank. I could also set up 2 ground stations, one down range of the other, so that the 2nd is just for refueling the carrier, so it can fly back to the first... but my idea was to have it able to launch from and land anywhere, regardless of ore concentration (well, the launch site should have ore, otherwise yet naother prop powered fuel tanker to bring fuel to the launch site would be a PITA)... but with the glide range, and the range of suitable launch altitudes (if fuel cell powered, certainly from sea level), I don't expect that to be a problem.

Kegarin's thread is cool, but I sense many (all?) of the SSTO designs are exploiting part clipping and fairings/service bays to shield parts from drag. My design doesn't do anything that I consider abusing part clipping, and from what I see of your 2 stager, it doesn't either.

[qzgy]

On 6/5/2020 at 2:14 PM, KerikBalm said:

Kegarin's thread is cool, but I sense many (all?) of the SSTO designs are exploiting part clipping and fairings/service bays to shield parts from drag. My design doesn't do anything that I consider abusing part clipping, and from what I see of your 2 stager, it doesn't either.

Glancing quickly through it I wouldn't discount all of them as funky heavily clipped monsters. Some of them yes, but others (if not most) look just like good engineering and flying.

Neat TSTO though. Why RTG's and not something like solar panels or fuel cells?

[KerikBalm]

6 hours ago, qzgy said:

Why RTG's and not something like solar panels or fuel cells?

There was space in the fairings, and I wouldn't need to keep reserve fuel for the flight back.

The single kerbal shuttle did use solar panels, and the cargo shuttles did use a pair of fuel cells to extend flight time

[OHara]

On 6/5/2020 at 5:14 AM, KerikBalm said:

What do you do if there's no ore above that altitude [7200m]?

Decline the contract to establish a base on Eve.  The rocket-powered shuttles can barely make orbit from 7200m, so if there is no ore in either biomes 'peaks' or 'Olympus' those shuttles will not work.

On 6/5/2020 at 5:14 AM, KerikBalm said:

I also climb at about 60 degrees, [..] this means that the 1st stage cannot land where it launched from.

During the propeller-powered flight, could you not fly west and then turn east just before the rocket-powered portion?  That might leave you within gliding distance of the base.

On 6/5/2020 at 5:14 AM, KerikBalm said:

Kegarin's thread is cool, but I sense many (all?) of the SSTO designs are exploiting part clipping and fairings/service bays to shield parts from drag.

Astrobond's SSTOs are simple constructions with no tricky adjustments, as are Kergarin's until the Breaking-Ground propellers that go in service bays -- as if to simulate an internal turbine with doors on the intake and thrust ports.  My 2-stage craft clips through the cargo bay, shielding from drag just those parts lying inside the bay, which I rationalize as an accurate simulation of a form-fitting fairing.

I know you know that clipping itself doesn't affect KSP's physics simulation (except of course as it should affect rotational momentum).  The clipped craft at left has the same drag as the basic craft in the center, but the trickery at right has fooled KSP into thinking that all the parts are on the trailing end of the stack, with no parts feeling the force of leading-side airflow.

So StratzenBlitz's artistic clipping has no effect on performance.   Putting engines inside fairings/service bays that are open on the end gives you drag-free thrust (recursive_mouse raised this to an art-form here) and EverAlpaca does mention when he resorts to this trick.  Probably we should always point out in challenges or on kerbalx (or in a you-tube if you do it that way) how we take advantage of KSP's physics engine, and what it did for us, so that new players don't worry that aesthetic clipping might be considered cheating, and don't stumble into exploits unless they want to.

[KerikBalm]

1 hour ago, OHara said:

Decline the contract to establish a base on Eve.  The rocket-powered shuttles can barely make orbit from 7200m, so if there is no ore in either biomes 'peaks' or 'Olympus' those shuttles will not work.

Well, later in career, with the tech tree maxed, I go full Science->funds conversion, and start doing what I want and not what contracts say. I may set it as my own mission

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During the propeller-powered flight, could you not fly west and then turn east just before the rocket-powered portion?  That might leave you within gliding distance of the base.

I suppose, it would take a bit more electrical power that way, and at the moment I'm not sure if I cover more distance climbing at 10-15 degrees (varies with altitude) to 11km, or at 60 degrees to Apoapsis (I suppose I could od the math, but while the initial ascent is at 60, it does decrease as I get higher, and curvature starts to become significant). The margins are enough that I think I could replace the 26 batteries (each 0,2 tons) for 14-16 fuel cells (0.24 tons each, + fuel) -at max consumption, 1 fuel cell can't feel 1 heavy rotor... but I should still have some batteries to meet peak demand, and to allow for moderate lenght flights without using fuel.

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Astrobond's SSTOs are simple constructions with no tricky adjustments, as are Kergarin's until the Breaking-Ground propellers that go in service bays -- as if to simulate an internal turbine with doors on the intake and thrust ports.  My 2-stage craft clips through the cargo bay, shielding from drag just those parts lying inside the bay, which I rationalize as an accurate simulation of a form-fitting fairing.

Well, I didn't look closely at astrobonds service bay trick... are the blades entirely within the bay, or just enoughto get shielded? In the latter case, I'd compare it more to a folding prop.

For your form fitting rationalization, I would also go with that. If you see my motor units, they are clipped in fairings. I offset the motors, build the fairing at 1.25 meter diameter, then move the motors (with blades) back down in line. The result is the motor is shielded, the blades are not. I just feather the blades to 90 degrees for the rocket portion. I rationalize this similarly. Its not like the contra rotating props on a Tu-95 have 2 motors with blunt ends seperate from the nacelles.

This image (already posted) should illustrate what I did:

Spoiler

On the 1st design (the single kerbal shuttle), this makes a lot of aerodynamic surfaces up front, and it becomes difficult to handle... basically impossible without thrust vectoring. It does help get the carrier to high AoA on reentry, and get it to slow down without burning up (I put deployment to 0, not 90, for reentry, maximum drag).

The 2nd design I have the rotors farther back (dry CoM moved forward by not having the orbiter attached + by having some engines at hte front the the craft), so that it is much more aerodynamically stable when the blades are set to 90, an dits under rocket power 

 

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I know you know that clipping itself doesn't affect KSP's physics simulation (except of course as it should affect rotational momentum). 

It also affects heating, if I'm not mistaken. It also affects lever arms, and can make craft sturdier by having forces torque attachments less. It also makes craft more compact to avoid breaking things on landing.

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EverAlpaca does mention when he resorts to this trick.  Probably we should always point out in challenges or on kerbalx (or in a you-tube if you do it that way) how we take advantage of KSP's physics engine, and what it did for us, so that new players don't worry that aesthetic clipping might be considered cheating, and don't stumble into exploits unless they want to.

There was also this one:

Which he says he uses part clipping in fairings:

"As drag is a major issue with getting up to Eve orbit, several measures have been taken to minimize drag:

• ...

• many fuel tanks have been clipped inside a fairing."

[Kergarin]

On 6/5/2020 at 2:14 PM, KerikBalm said:

 

Kegarin's thread is cool, but I sense many (all?) of the SSTO designs are exploiting part clipping and fairings/service bays to shield parts from drag. My design doesn't do anything that I consider abusing part clipping, and from what I see of your 2 stager, it doesn't either.

Thanks!  and congrats for building a reusable Eve craft!

But that's wrong. Out of the actual 14 listed crafts, only 2 use clipping.

I do not add crafts with exploits or unreasonable clipping to this list. And if I make the exception to add a craft with clipping to the list, it needs a really good reason.

These 2 exceptions were:

@OHaras craft, which you already said by yourself you would go with that.

@EvermoreAlpacas second craft, because it uses stock props. Well it also uses clipped engines, which I generally don't consider legit, but for the achievement of building the first working sealevel SSTO, I made this exception. 

 

My personal crafts do not use any clipping at all. Neither my old SSTO rockets, nor my suborbital catch, and the new cargo bay props are not clipped.

Cargo bay props are rotors and blades completely fitted into a Cargo bay. They only work and created drag when the cargo bay is open, and they don't work and don't create drag when the bay is closed.

You can see it right here

https://m.youtube.com/watch?feature=youtu.be&t=9m1s&v=hdxJ5dGu4o8

 

 

On 6/8/2020 at 9:41 AM, KerikBalm said:

There was also this one

Which he says he uses part clipping in fairings:

"As drag is a major issue with getting up to Eve orbit, several measures have been taken to minimize drag:

• ...

• many fuel tanks have been clipped inside a fairing."

That's why it wasn't added to the list. The list is only what's in the first post. What people post by them self doesn't count. I sadly just didn't find the time to answer to this by now.

 

Edited June 9, 2020 by Kergarin