In Progress Let's go to the Moon and do the other things (Kerbal Space)

[Burning Bridges]

Meanwhile Duna 2 has reached the desert and could operate some more.

Compared to the first day which went by very quickly, that took actually longer than I expected. May there be some (spherical) distortion issues on the Pole, and the Schröder Crater appeared much larger than it actually is?

Looking into a steep valley.

Only a few hundred meters left.

 

[Burning Bridges]

The Russian specialists have managed to move their probe, and the probe's solar panel has now direct sun exposure.

It's never a good idea to equip only one solar panel. Of course the russian specialists realized their mistake when it was too late. Only a desperate maneuvre with the thrusters could save the probe.

Sun exposure is zero. If this remains, energy supply will die soon.

with J thrusters and some forwards / backwards movement with H and N

the probe moved a little bit sidewards

until some required sun exposure was gained

The probe can now remain on the surface and be used later, perhaps.

 

[Burning Bridges]

If jet engines are possible on eve, I think the most fuel-efficient way to make a lander/return craft is building it as a spaceplane to take full advantage of the thick atmosphere. It'd make finding a

I think there are enough flat areas on Eve. Most of it is actually flat, dull landscape. I found it much harder to look for hills and craters which look interesting. And pinpoint landings on Eve demand huge amounts of fuel too.

 

[Hellraiser]

Nice fighter, SV approves of that I think.

As for clouds on Eve, they're working on adding clouds so we'll probably see them in one of the future updates, along with weather. I don't entirely agree with the Jool system being pretty dull. Laythe may seem improbable, but with enough tidal forces and the Laplace resonance like on Io (which is closest to Jupiter like Laythe is to Joon) it would be possible to have liquid oceans that far out because the resonance would feed energy (heat) into the ocean/atmosphere. Also it's fairly difficult to land on the islands (without using wings and jets which do work there). Vall is a nice ice world and Tylo is of course the ultimate lander challenge. I do agree that outside of Eve (which got a slight facelift) and Duna the celestial bodies could use more detailed terrain (ice cracks on Vall would be good). Not to mention more varied environments of celestial bodies in general, the volcanic hellhole being the most obvious one.

Now for some of the things I have been screwing around with, just to show that Polant thinks big:

The Krzelecki Cruiser with a Keweliusz Heavy *Dunar* Lander. Anyway the goal of this design to have something versatile for 3-man manned landings anywhere in the system, the custom lander docking in parking orbit.

Total crew: 5 Cosmonauts, 2 in the bridge (the lander 2-man pod), 3 chilling in the hitchhiker storage below it. They were originally in the lander which docked in orbit, but they couldn't really spend months in that cramped thing so I spacewalked them there. The double-jumbo stage actually still had enough fuel that I didn't need to jettison it before the transfer burn and dock an actual full fuel tank like I planned (and it was 70% empty). Not sure if they have enough fuel to return Kerbin, I think they do but worst case scenario I send them a tanker. The thing is currently studying Duna. I dropped additional equipment to explore the shit out of it, including:

The Weba Duna Rover, 100% stock parts 2-cosmonaut Ion Engine rover. My best stock-only rover so far. Half of its power comes from 16 RTGs, good thing radiation is not an issue, yet, the rest comes from single tile solar panels (as regular ones are too fragile to use on a surface/atmospheric vehicle), so it can even accelerate during the night. Top safe speed on Duna is about 30 m/s, can go 40 m/s but good luck slowing it down as you dodge rocks and jump over small bumps. It's 100% vacuum approved, that is it uses RCS for turning and also as a reverse/booster/emergency break. Developed a safe way to drop it into atmospheres so it lands in one piece, as the probe pod is it's primary command pod you can drop it after a mission and drive it to the lander. No need to send it manned (since it can't return to Kerbin anyway).

Meteor-4 Ion-Glider Duna Probe. This thing took a lot to make, after I started prototyping it it turned out Scott Manley did one as well, but didn't send it to Duna. Outside of 2 RTG added as weight/backup power this is nearly 100% solar powered. Can achieve sustained flight without using the infinite glide bug, although you need a hill to make it take off from Duna's surface due to silly landing gear touching the ground making it harder to take off. Once a part of it is in the air it can fly (with no bug use) up to at least 4 km and 70 m/s. It can probably do more, but this happened:

Fucking Ike eclipsed the fucking sun! Yes, that does in fact cut all your solar power supply, even if the sky doesn't get noticeably darker. Will try to see what the thing can do after conditions improve. Goddamn over-sized close moons...

 

[Ulminati]

Once a part of it is in the air it can fly (with no bug use) up to at least 4 km and 70 m/s. It can probably do more, but this happened:

Fucking Ike eclipsed the fucking sun! Yes, that does in fact cut all your solar power supply, even if the sky doesn't get noticeably darker. Will try to see what the thing can do after conditions improve. Goddamn over-sized close moons...

Things like that is why KSP is my GOTY

 

[Hellraiser]

Good thing I prepared for such an eventuality with the RTGs and the thing is essentially a glider with just enough thrust to fly on its own, so I landed it safely during the eclipse. Judging by xenon gas use it could probably circumnavigate Duna assuming I could play KSP non-stop for like 12 hours. Due to its wing surface I think it could glide through the nightside or move fast enough to be essentially in the day side during the entire flight (bar the occasional eclipse). Either way it has full scientific instrumentation (why else do it if not for science?) so I have a lot of data about atmospheric pressure on Duna now.

 

[Burning Bridges]

This design deserves many brofists. Could you upload the craft file?
What if you just add a small reactor, wouldn't it be enough to cut off the engines and make a glider landing when the sun dissappears?

One of the things I always wanted is a blimp that could maintain a constant height over another body, and allow extended exploration. Unfortunately no one ever made an inflatable balloon mod (there was one but it was ridiculously large).

 

[Ulminati]

I think the Brotato scientists already added reactors to it (RTG). You'd need a LOT of them to keep a Twin Ion Engine active though. It'd probably make the plane too heavy.

 

[Hellraiser]

Yeah I have 2 Radiothermal Generators on that, they also double as a main structural pipe-thing. I think they're the heaviest part on the craft outside of the ion engines+xenon tanks but they help it remain balanced. I really went all out to make it as light as possible. I was actually surprised it has more than enough power for both engines when on Duna. Probably could put a third engine on it but I fear it would make the tail too heavy and not give a lot more thrust as power generation would be too small to go at full thrust on 3 engines. I think I'll experiment with the concept a bit and try to design a 1 engine and overall lighter version with just two wings.

Was inspired by some very old discovery documentary I remember from way back where they shown some CGI of a proposed mars probe plane, although that one used an electric propeller. I figured the ion engine may not have enough power, but then I saw how fast and how high the Weba Duna Rover jumps when going over hills when that thing isn't optimized for drag and has no lift.

Figured that even with 1/10th of pressure at ground level but 3 times less gravity (so 3 times less lift needed to stay up) you could maybe get it into sustained flight. Also you have less drag on the surface so you can go faster and more airspeed=more lift. That and having to redo a 20+ km drive from the rover's landing site to the lander several times due to rocks, hills and not enough safe surface area from braking annoyed me greatly. Flying above all those damn rocks is not just faster but also safer. The glider is actually more stable on the ground than the rover at higher speeds. Probably because it landed in flat terrain and not the hilly hell the rover did. Ironically it had problems taking off because of that, if it jumped off a hilltop at 20 or more m/s it would start flying. Duna is a harsh mistress, she makes you land in the places most ill-suited for the craft you design.

I'll upload the .craft file a bit later, although you'll probably want to make your own carrier rocket for it or add more RCS fuel as it needs it for stability. The glider itself can easily land from orbit if you aim for aerobraking at 3 kilometers above surface and keep it pointed prograde when you get below 40 km. It will end up having a lot of airspeed so you may end up flying half way across the planet if you don't try to get it lower to lose more of it due to drag. I think that at the speed it entered atmosphere at 15 km it started generating enough lift. I forced it to dive to land it as I was eager to see if it actually gets off the ground on its own.

 

[Hellraiser]

Here's the ion-glider .craft file put it into the VAB folder, unless you want to change the glider itself, then put it into SPH.

Its pre-final (or final) stage is 3 xenon tanks+RCS thrusters, as a backup if it had to use ion engine for the final orbit lowering. The thrusters are there to help it with orbital maneuvers, all of that is dead weight in the atmosphere so ditch it before going in.

 

[Hellraiser]

I pushed the damn thing to the limit, 129 m/s and about 6330 meters are the top stable altitude and speed, also the optimal one for long range flght. That's assuming the flight prograde is neutral altitude-wise which means a lift/weight=1. I won't go faster or higher, although you can get more speed in a dive obviously. Flew over 1/8 maybe 1/6 across the planet using about 55% of the xenon fuel. Sun exposure fell from 0,9 to 0,78 during the flight. Pressure was about 0,0250 at max altitude. Takes it about an hour if not more to go that high/fast.

 

[Burning Bridges]

That's a really nice flying machine .. How did you fly it to Duna? A gigantic spaceplane would be most befitting.

In the future it would be great if they added a feature to assemble stuff during the mission, launchpads on other planets, or (more likely) folding parts.

 

[Hellraiser]

The carrier rocket was fairly simple although it requires RCS due to the asymmetry of the glider (it's optimized for flying rather than getting to orbit(s)), it's in the .craft file I posted. Last stage was a NERVA plus a tank or two tanks of fuel and 2 small RCS tanks. More than enough to get it from parking orbit (I think it was a 2000km altitude orbit) to Duna and into a desired aerobraking trajectory.

I tried to make a sub-orbital carrier spaceplane for the on-kerbin high-altitude test (to see how much lift it has at duna-like pressure), but the damn thing is rather hard to do. Settled for a 20km altitude jet instead as air-pressure is similar to Duna's at around 11km IIRC. Getting a spaceplane beyond LKO is kind of pointless for practical reasons, although glider-based landers could prove useful. Except maybe for Laythe, a SSTO spaceplane lander would be the best bet there IMO.

They're planning on letting you build stuff in orbital VABs or on other planets if you haul the parts there, probably what the cost values in part details are for. Like you haul X worth of Parts and can build up to a budget. Would be the best way without it becoming tedious when you run out of struts because you hauled 100 instead of 101 or something. Some retard complained on the forum that it (orbital and other VABs) would ruin is his immersion because it would be too SF. Yeah, the only reason we're not building rockets in orbit is not because we don't have the tech, but due to costs. Budget problems are alien to Kerbals luckily. Obital VABs or Munar VABs would make building those really big ships way easier, without having to rely on docking (which isn't all that good for making large vessels).

You know what I would like to see? Being able to connect vessels on the ground with power cables and fuel lines for pumping fuel during EVAs. Now if you want to refuel a lander on the ground you would have to really screw around with the docking ports so that you could dock a makeshift fuel tanker/rover hybrid. But with EVA fuel lines you would just land a tanker somewhere, drive it close enough (unless you think you can do a pinpoint landing or use mechjeb for that, but rovers tankers would be better IMO) and have the dolts connect it, pump it and disconnect afterwards (or face a catastrophe during launch). The power cables would be real nice as it would allow you to have a single powerplant for the entire surface base complex rather than having every module with a RTG/panel.

BTW they're adding a new dwarf planet in the 0.18.2 hotfix called "Eeloo", has a pluto-like eccentric orbit shape (relative to Jool) where it gets closer than Jool but then way further away. Looks a bit like Europa from what I saw.

 

[Burning Bridges]

Eeloo ia a cool planet, because it adds something new, and it looks "right". It reminds me less of Europa, which is flat like a billard ball, but it's a bit similar to Ganymede.

But I'd rather have such bodies as moons of Jool or the ringed Saturn which they are inevitably going to make. I already suspect Eeloo will be too hard to reach, like many of the interesting planets. At least it could allow some interesting Jool gravity swings.

I would also prefer to carry parts, or better pre-assembled modules to space, having money to spend in space is too gamey.

 

[Burning Bridges]

In the past we have always been on the forefront of technological development. In fact we were the first nation that ever landed on the Moon (even though at the cost of many lifes).

But we became painfully aware that we were left behind by small nations like Poland, Kenmark, West Kermany, etc, and this can not go on.

At last the discovery of new planets has revived our governments interest in space exploration. Because of our space budget being so small, Congress passed the first budget increase since I came into office, and this means we can begin a new phase in the space race.

While we will continue the search for the most simple, inexpensive propulsion systems, I also started a research project to develop a much larger rocket. One that can could reach much more distant targets like Dres and Eeloo, and carry substantial payload.

The research project came up with "Jool", a rather powerful rocket, but still within our budgets limits.

Jool 1-A

total weight: 137.5 tons
Total deltaV: 13,400 ms
Vmax reached from Kerbin: 8,500m/s with 1.5t payload (this is the "dumb" vertical takeoff test). If the payload includes another propulsion system, much higher speed could be reached.

We did not test the with only the minimal probe core, but that configuration could exceed 10,000 m/s.

JOOL-1A.craft

Among a million of other things, we are very proud that we were the nation that invented the computer. And this allowed us - for the first time - the development of a new rocket by actual calculations! We are very surprised that we actually achieved results!! The formula to calculate is: deltaV = Isp * g * ln (m1/m2)

Here you can see how powerful our computers have become: launch_vehicle.jpg

Interplanetary stage (J-3A)

weight: 11.35t
total weight (including payload): ~12.35t*(1)
thrust: 60
deltaV: 8189 m/s*(2)

*(1) other configurations are possible. For example we could exchange some tons of fuel for more payload, with decreased performance.
*(2) performance could be further increased by asspergers staging. There is still over a ton of dry weight in the tanks, and we know that.

For the design of our upper stage we compared the Nuclear Engine (NERVA) and the LV909.

engine weight thrust Isp
NERVA 2.25t 60 800
LV909 0.5t 50 390

(Isp is the specific impulse in vacuum)

It quickly came out that the NERVA is the more efficient propulsion for interplanetary travel. As a reminder, our previous generation used a LV909 and 1 standard FLT-800 tank (4.5t). We were quite surprised that compared to this design, deltaV could be doubled by using a NERVA, especially if we also use larger amounts of fuel!! It is ideal for interplanetary stage if the interplanetary stage uses 9 tons or more of fuel.

In the table you see the deltaV increase. (The calculation also considers a 1t payload in addition to the stage weight)

Engine Fuel deltaV (m/s)
LV909 4.5t 4079
LV909 9t 5376
NERVA 4.5t 5591
NERVA 9t 8189

However, the performance improvement in the upper stage comes with a big problem. That the total weight of the J-3 stage will increase from ca 6t to 12t!

So we had to tax our brains how to build a stage that could carry the NERVA into orbit.

Second stage (J-2A)

weight: 21.5t
total weight (including payload): 33.75t
thrust: 430
deltaV: 2332 m/s

We still find that the design of a second stage is usually the most difficult, and the one where most mistakes were made in the past.

Our research considered 3 engines:

engine weight thrust Isp
LV909 0.5t 50 390
Rokomax 2.5t 220 390
LVT-30 1.25 215 370

The LVT-45 was not considered, because it is heavier and delivers less thrust than the LVT-30. The vector thrust is not required. NERVA engines are totally unsuitable for the task, because their Isp in athosphere is worst, the engines are much heavier and deliver less thrust.

At first, the Rokomax and the LV909 appear ideal because of their high Isp in vacuum (390). This lead us to some proposals which deliver a lot of deltaV on paper. But in practice these stages do not fly because their thrust is too low.

Keep in mind that a "real" second stage is supposed to be able to bring the third stage into orbit. If you have to battle with your third stage to even reach orbit, it is not good design. That means, our stage must reach ca 2400 m/s, with a payload of 12t! And for that, you require a lot more thrust than these two engines can deliver!

Our experience is that designs with the LV909 and Rokomax engines struggle a long time to overcome gravity, and still end up way short of orbital speed. Even if you combine enough LV909s to get enough thrust, their total weight becomes a factor. The "large" Rockomax engine fares even worse than the LV909, because it has even less performance than 5 LV909 combined! In the end, designs relying on these two engines (Isp 390) proved fruitless.

Our end result is that as long as you keep it simple, the LVT-30 is the best engine for a second stage. Although it's specific Impulse is lower, it delivers a lot more thrust compared to its weight.

Our J-2A uses two combined LVT-30s and 18 tons of fuel. resulting in a deltaV of ca 2300 with ca 11.5tons of payload.

It does not always reach the orbital speed requirement, but is so close that only a small push with the third stage is needed.

First stage (J-1A)

weight: 103.75
total weight (including payload): 137.5t
thrust: 1505
deltaV: 2963 m/s

The design of the first stage was the easiest, because we had a lot of experience with this. We already knew that LVT-30s with 3 FLT-800 tanks deliver excellent performance. For our J-1A stage we combine 7 of these, resulting in 94.5 tons of fuel and a total thrust of 1500. Considering a payload of 33.75 tons (for the other stages) this results in a total mass of 137.5t.

We find this design superior to a big Rokomax engine, because while it is roughly equal in thrust and weight, it delivers much better efficiency (Isp 320 versus 280).

A design with Aerospikes may be somewhat better, but we made it our principle to not use Aerospikes for a number of reasons.

In practice the first stage burns out after 3minutes, at ca 900ms / 40km, a height on which the engines in the second stage have their full efficiency.

 

[Burning Bridges]

Recently there was new thaw weather in our government, and I have become permission to return back from holiday!

Koviet space agency can thereby announce we also have rocket in development, and she will leave performance of Kamerican "Jool" behind!

We have taken idea from American to use nuclear motor - but found better solution for acceleration stage. We use total weight of less than american (130t), but better performance. This may be possible because we use fuel line. We do not fully understand, but it true.

Compared to "normal" rocket this still very expensive for us, so no testing possible. Test must be done on the launch. And unlike American which have computer, I cannot show you exact figures. I have asked technician to make calculations with hand. If right our rocket can go faster than American, and also carry more payload.

Rocket not fully developed, but prototype really exist.

Novaya Raketa "Svetlana Boginskaya" 2: N2-01.craft

 

[Burning Bridges]

Privyet!

Today, prototype of "Svetlana Boginskaya" have fly, and make us very satisfied about our expectations.

Rocket fly very easy and reliable.

Burnout stage one at satisfactory altitude.

And now stage 2, he need a little more work with thrusters.

Separation stage two with problem to keeping attitude, but speed very satisfactory.

Now burn stage three, nuclear motor take 20 minute real time.

 

[Burning Bridges]

Spacecraft reach end of nuclear motor fuel.

With small motor and last reserve RCS fuel spacecraft make final 10,178 m/s, can still be improve, but is already more than enough.

 

[Hellraiser]

10,178 m/s? That's a lot, think you could get to Moho with it without a gravity slingshot of Eve? I was honestly shocked when I saw how much delta-v my Moho probe needed to change inclination, not to mention the final transfer burn. And I did save like 1k or 2k delta-v by doing a tight slingshot around eve.

Anyway, to my surprise, it turned out that my Duna Rover now burns through RCS a lot faster than it did. It seems it benefited from the old buggy RCS usage a lot but 0.18.2. kind of changed that. However it turned out that the lander pod can easily turn left and right using E/Q with no RCS. So now I'm making an improved version with 4 ion engines.

 

[Burning Bridges]

Yes, I also noticed the change (before I could use almost limitless RCS for my Eve missions). With the changes in 18.2 my rockets now require strict RCS "management". I usually have to disable the ones in my pod, so that they won't get drained during the launch.

Thrusters still deliver considerable deltaV, but run out fast. I ran into problems on a Lunar test, because ASAS used up my monopropellant, and the ship become extremely hard to control. The containers are also a lot heavier. Is there a way to create action groups to disable a group of RCS containers?

Concerning deltaV, I realized that a lot more was needed if I ever want to fly to Moho / Dres / Eeloo. My goal was 10,000ms. This can be done with a single NERVA, if it has enough fuel. Most of the problems were in the second stage, which needs to bring the NERVA into orbit first. I think that was the reason we have all struggled with bringing the NERVA into an orbit without using its fuel. Neither the LV909 nor the Rokomax engine proved very suitable, as I as outlined in my previous posts.

As to the maximum I don't think there is a limit nor what is sensible. But from my calculations a block of three LVT-30 plus 36t fuel is quite ideal. I calculated 3350 m/s deltaV with ca 12tons of payload (NERVA + 9tons of fuel + 1 ton payload). This block is also easy to build ( 1 orange tank ), and flies normal. Theoretically one could cluster more and more of these blocks and see how fast this gets closer to 15,000 m/s, and so on. But to really make use of that I'd need to increase the weight of the nuclear stage as well and start my calculations again ...

10,178 m/s? That's a lot, think you could get to Moho with it without a gravity slingshot of Eve? I was honestly shocked when I saw how much delta-v my Moho probe needed to change inclination, not to mention the final transfer burn.

How much do you think it would have needed? Do you think more than 10,000 m/s is needed for any type of mission?

Eve slingshot sounds pretty complicated (I am not good at such maneuvres). Is it possible to use a solar flyby instead? The sun is dead easy to hit and the speeds are amazing.

 

[Hellraiser]

An Eve slingshot needs a very close rendezvous which bends you trajectory "backwards" (towards Eve's retrograde), not to mention adding energy. Puts you into a half-way between Eve and Moho Orbit. Not that hard really.

My Moho probe was basically the tiniest ion probe I could build, stuck unto a large "standard" tank and a NERVA. The NERVA was used to finish insertion into parking orbit and was almost out fuel before I got into Moho periapsis and begin an orbit insertion deceleration burn. It ran out of fuel then and the ion engine finished the job (fun fact 4 panels are overkill for Moho, you only need 2 for one ion engine there).

I needed 1k delta-v to change inclination to match Moho's after the slingshot and nearly 2k delta-v to decelerate to get into Moho's orbit. The transfer burn after the slingshot was 1,2k delta-v. Probably at least 1,7k if not for the slingshot.

Needless to say I am very skeptical about making a manned mission there, although at least the landing and return to orbit would be easier than on Eve. Getting back to Kerbin's orbit though, that's a different story.

 

[Burning Bridges]

Slingshots are cool. I mean that we have the ability to use them now. I'm just not very good at them! I am not good at anything when it comes to flying. I only once tried a slingshot around the Moon and ended up on a worse trajectory than without it. I was going to Eve but it brought me half way between Kerbin and Duna

Also I have zero experience with Ion engines. But a very good piece of information that your solar panels got more efficient closer to the Sun (that's affirmative is it?).

If I add up those figures of yours, 10,000 may do it. Being able to go beyond, to 15,000 would be much better of course.

So far found no way to use the Tsyolkovsky equation to calculate the exact speed, nor seems the guy who does the tutorial. For example he kept referring to 4000 m/s being needed for orbital insertion.

But when I compare the figures I calculated to my actual result, they are off by a constant factor, which is ~ sqrt(2). For example a calculated 13,000 m/s would eventually be 8,500 m/s. I am aware that I'm now in the realms of guesswork, but so far I can compute the relative changes in may velocities quite well if I apply that factor, that is, divide the computed deltaV by it. Even if it is nonsense, it gives me an idea of the relative changes I can expect.

I quickly calculated a bit and using this principle, I estimate that a single NERVA could require 36tons of fuel to reach 15,000 m/s. That's four times the size I use now, which also means that the rocket under it would need to be four times as big, 500 tons or so!!

But what I know for certain, is that a lot can be achieved with Asspergers staging. For example a NERVA stage that reduces dry weight from 1 ton to 0.25 tons by dropping tanks could gain an additional 1000m/s. I just don't use that because you have to watch the tank content all the time, it's not so much fun in practice.

 

[Burning Bridges]

Needless to say I am very skeptical about making a manned mission there, although at least the landing and return to orbit would be easier than on Eve. Getting back to Kerbin's orbit though, that's a different story.

I would love to try that, but in order to even have the remotest chance of a return would require Moho orbital rendezvous, which I haven't managed yet.

In fact, if I want to return to a manned space program would require me to learn Lunar orbit rendezvous first. Even that is a daunting proposition.

 

[Burning Bridges]

An Eve slingshot needs a very close rendezvous which bends you trajectory "backwards" (towards Eve's retrograde), not to mention adding energy. Puts you into a half-way between Eve and Moho Orbit. Not that hard really.

If you had a screenshot or a link to a video, I'd really appreciate that.

 

[Burning Bridges]

I have small information for collegue who still want drive vehicle over Mun or new planet. Comrade CleverBobCat have make realistic Lunokhod!!

Unlike cheap dyety rover used by imperialist countries, this one now use energy and have real weight of 1.5t, so will deliver realistic and full of challenge gameplay.

http://kerbalspaceport.com/0-18-1-lunokhod-1

I am not sure when we can use ourself, because he is quite large and does not fit well over our rocket.