It's Only Rocket Science! (RSS/RO/RP-1)

[jimmymcgoochie]

So Gemini is more expensive than I thought. Not 150k funds, but instead 375k, which I don't have.

YET.

First rendezvous requires a crewed vessel that can change its orbit, which is exactly what Gemini can do. How convenient!

After spending most of that advance money unlocking all things Gemini (except the heatshield, which is in another node that I haven't researched yet ) and the rest on KCT points, the next launch was a pretty boring Green Cucumber contract commsat.

With that contract done, there was space to accept another really lucrative one- first EVA. Again this is something that Gemini can do and will most likely happen on the first mission.

This time, the advance money was spent on an R&D upgrade and some more KCT points to get that second build queue going a bit faster.

Orange Trombone 4 was next to launch. I must have forgotten to take screenshots of it in orbit, but it worked just as well as the previous three and has begun gathering reconnaissance- er, scientific photographs.

And on the subject of the Orange Trombones, the second and third satellites' film reserves have run out so it's time to return the samples.

Capsule number two came down almost on top of Tehran, which I'm sure would cause absolutely no diplomatic problems whatsoever...

And then capsule number three re-entered somewhere off the far eastern coast of Russia and splashed down into the northern Pacific.

Then another Green Cucumber launched for a satellite contract, this time a tundra orbit. Completing this contract unlocks the high-value commercial Molniya and tundra orbit contracts which were one of my staple sources of income in my last RP-1 career.

The design will need a couple of minor changes to do tundra orbits on a regular basis as the batteries are insufficient, running out at almost the exact moment that the craft reached its apoapsis (I did the burn a little bit earlier to avoid this).

I've also just unlocked bipropellant RCS options, though HTP is good enough for these commercial sats and will save a bit of cost and build time over upgrading them.

And now I have a bit of a problem. See, the Gemini service module is about 2.9m in diameter at its widest point, but the fuel tanks I've tooled up to this point are only 2m in diameter. I could make some wider tanks, but that's very expensive and I can't really afford to do so right now; or I could do what I did with Mercury pods in my last RP-1 career and just stick the pod on top of a rocket that's considerably narrower.

I'm sure there's absolutely no aerodynamic reasons why this isn't practical... The rocket is identical to that used by the Green Cucumber and is very reliable, but I'm still going to make an abort system just in case I somehow get a failure with a 0.03% chance.

This took a few iterations to get right. Some tests worked fine:

But take the same design and do an abort at a higher speed and altitude:

Parachutes are important!

In the end I decided to get rid of the Gemini RCS pack which had repeatedly failed during abort tests and just stick a generic stack parachute on instead, along with some RCS thrusters on the top of the pod itself. The nose section and drogue have stayed for now, but I'm thinking of getting rid of those too and replacing them with a procedural structure for a nosecone, or the Gemini docking part instead when I start doing docking missions; the drogue definitely isn't needed for this thing as it slows down to barely 100m/s in freefall on its own.

Rudolph-spec red nose not confirmed for production.

Spoiler

Full album: https://imgur.com/a/YB0sdqw

Coming soon: Not a lot. I'm away for a week with no way of playing even stock KSP let alone this heavily modded version, but when I come back I'll FINALLY do some Gemini missions. This time I mean it!

 

Edit: Well this sucks. Tested positive for coronavirus the day I'm meant to be flying home for a week. Boo. Two year streak broken.  

On the flip side, that means more KSP time so the next update will be sooner. 

Edited April 11, 2022 by jimmymcgoochie
Finally got the 'rona

[Maria Sirona]

3 hours ago, jimmymcgoochie said:

positive for coronavirus the day

Oh no

[4D4850]

On 4/11/2022 at 3:59 AM, jimmymcgoochie said:

Edit: Well this sucks. Tested positive for coronavirus the day I'm meant to be flying home for a week. Boo. Two year streak broken.  

On the flip side, that means more KSP time so the next update will be sooner. 

Sorry to hear about this. I hope you get well soon! Don't overexert yourself with work (even game work, or making game related things), get plenty of rest, etc., etc.   Among other reasons, I'd much rather have 1 or 2 really good posts, than 3-4 posts by a burnt-out @jimmymcgoochie.

[jimmymcgoochie]

Need money? Launch a commercial communications satellite into a Molniya orbit.

Hundred grand, bosh. All it took was ~3.5 weeks of VAB time.

Remember that communications network I put up a while ago? The one I said I'd fix so the satellites stayed in position? Yeah, that didn't happen...

Once I get some geostationary satellites going this trio can be binned, but until then they still cover some of low Earth orbit.

Next to launch is Green Dragonfruit 3 heading to the surface of the Moon.

The original plan was for a direct descent at a very shallow angle, however that would have resulted in a landing in the lowlands, which is where Green Dragonfruit 2 landed. Nudging the periapsis to just above the terrain then adding a significant amount of normal burn to the capture/deorbit burn enabled a landing in a big crater which is classed as "major craters" instead. More science is always better!

Unlike its predecessors, Green Dragonfruit 3 uses bipropellant hypergolic RCS instead of HTP, giving substantially more thrust and allowing it to perform most of the final descent using just the RCS thrusters rather than the main engine; the ISP is more than doubled, allowing the lander to use just two fuel tanks instead of four without losing any delta-V and to carry heavier but more rewarding science experiments.

And touchdown!

There's one more lunar landing contract to do, plus two farside landing contracts that will require a communications network around the Moon, something I'll have to look at soon.

A few simulations of sun-synchronous weather satellites were done, some more successful than others...

One layer of MLI was apparently too many for this thing. It was shortly after this that I discovered I'd already made a sun-synchronous weather satellite launcher and started modifying that a bit with better tech instead.

Next to the launchpad was Green Banana V2, attempting to break the streak of bad luck that has afflicted the Venus-bound missions so far: the first had no signal at Venus, but got a lucky gravity assist that threw it back towards Earth where it just managed to call home and send back its data to grab the flyby contract, while the second had no signal, suffered an engine failure when attempting to brake into orbit and then threw its atmospheric probe into the upper atmosphere at a frankly ridiculous 12km/s where it was immediately incinerated; no helpful gravity assist this time as the probe was hurled away almost to the orbit of Vesta with no realistic prospect of hearing from it again.

This time the antenna has enough power to reach Earth from Venus regardless of where the two planets are in their orbits, while there should be enough fuel on board to capture into an orbit that makes atmospheric entry survivable (hopefully) while still returning plenty of data from orbit.

Pushing the limits of the 350 ton pad by stretching every fuel tank to the maximum that tooling allowed, then adding four Castor SRBs that were fired in pairs to help it off the launchpad, should mean there's more fuel available for orbital capture at the other end. The third stage to perform the transfer burn was swapped from an RD-58 (S1.5400) to an RD-119 which has superior thrust and ISP, however this also meant that the third stage avionics were insufficient and some fuel had to be dumped to make it controllable again. Oops.

The transfer burn was still done using only the transfer stage, with a course correction plotted in interplanetary space to get a nice, close encounter with Venus. Solar panels pointed to the sun and avionics shut down, the probe will coast for a hundred or so days.

Spoiler

Full album: https://imgur.com/a/7YFUV15

Coming soon: The first Gemini mission is next on the build queue and contracts for first rendezvous and first EVA are going to be completed. I don't really have much choice, the deadlines are too close to build a second craft...

 

 

[jimmymcgoochie]

At last, it's Gemini time! Yellow Gong A1 will take both of my current active astronauts into space for a few days, hopefully bag some easy contracts and then bring them back safely. Probably.

Sticking a 3 metre Gemini service module on top of a 2 metre rocket booster is fine, they did this in real life, right?

The launch was troubled to say the least- no engine failures, but it just underperformed massively and the initial plan to rendezvous with a satellite in a 300km orbit became a plan to rendezvous with its own second stage became 'just get to orbit at all and worry about the rest later'. It got to orbit, but only 150km up and using half of the service module's propellant in the proccess.

Klaus and Vera took turns going outside, performing the first EVA on 1964-07-03 and enjoying the views.

And now for a bit of a fortuitous mistake.

I built a Green Cucumber to complete another Molniya contract, but I accidentally built the 1k version when the contract requires 1300 units of payload, so it can't actually complete that contract. It got rolled back from the pad when I realised the mistake and then kept in storage for an inevitable future contract while a Green Cucumber 1.5k got built to complete this one.

That spare rocket is about to come to the rescue!

With oodles of delta-V, five engine ignitions and over 12 hours of battery life, it's perfectly capable of rendezvousing with the Yellow Gong in orbit and salvaging that contract from the brink of a very expensive failure.

Just after the velocity-matching burn happened, the Green Cucumber's battery died; its work was done, though, and Klaus piloted the Yellow Gong over to park mere metres away from the now derelict craft.

Rendezvous completed, ground controllers manage to hotwire the avionics on the Green Cucumber and get a few seconds of control out of it, giving them just long enough to order it to deorbit itself rather than remaining in a 150km 28-degree orbit where it could hit something in future. That's my parking orbit for most launches, so best to keep it as free of debris as I can (merrily ignoring all the boosters that I've left there due to a lack of deorbit motors).

A few more days in orbit to test out the Gemini systems a bit more (need a bit more hydrogen for the fuel cells, and the helium pressurant for the thrusters is going down faster than expected) and to complete some crew experiments that take up to six days, not to mention bagging duration records of 2, 3 and 7 days on orbit, and then it's time to come home.

The remaining fuel in the service module is used to lower the periapsis, before the four solid rockets in the retrograde section (medium separation motors, not the "proper" retrorockets) fire to complete the burn. This subjects the crew to a quick burst of 12 gees, which isn't great; fine for launch abort, not for space, so in future I'll swap them to fire in pairs instead.

The capsule wasn't entirely stable in the upper atmosphere and seemed to want to flip around pointy end first, possibly because I'm not using the normal RCS pack and parachutes, but once into the thicker air it stabilised and performed a textbook lifting re-entry to reduce the G-loads.

Safely splashed down into the Pacific ocean. Just the usual glitchy ocean of perpetual bounciness to deal with, but recovering the pod solves that problem before anything explodes.

And now for the rewards.

Much money was gained from all those contracts and records, well over a hundred science was gained from the crew experiments and both crew add several years to their retirement dates after their EVAs; Klaus also gets his first star after failing to get it on a Mercury flight. Both crew are off on holiday for a few months, returning in late September.

However, it's not all good news: I now need to completely redesign the Yellow Gong to give it substantially more delta-V, fix all the minor niggles that the first flight uncovered and then make sure that future missions all use different crew experiments to maximise the science gains from these expensive flights.

Spoiler

Full album: https://imgur.com/a/speuPdv

Coming soon: Many simulations of some very questionable rockets.

[jimmymcgoochie]

More interplanetary windows are approaching and I should really start building some probes to throw at them. I haven't even launched anything towards Mars yet; at this point in my last RP-1 career I had crew on Mars.

The orbiter portion of the Yellow Banana V2 will suffice for a Mars mission, shorn of its lander and with bigger solar panels and an RTG for supplemental power. Another modification with no solar panels and two RTGs will do for Vesta and Ceres flyby missions, but the Mars mission should have the delta-V to try and orbit.

Test launch successful, there's plenty of fuel to shoot for Mars and the try to capture into orbit when it gets there; if not then it's a very overengineered flyby probe.

I've also made some major modifications to the Yellow Gong Gemini missions, most notably adding a third booster to the launch rocket and tweaking some propellant levels. One more flight of the A variant should be enough to prove that everything works properly, then it's time to move on to the B variant and docking.

And then there was this thing:

It's not my finest work, OK? But it did re-use a lot of pre-tooled parts to save costs and carried a load of new science experiments to polar Earth orbit, including an improved TV camera that can do biome scans for that contract I accepted before I checked if I had any parts that can actually do biome scans (fortunately, TV cameras can do them).

Orange Tuba 2 ended up in a nice polar orbit and will be gathering science for many months to come.

And now for some really dubious choices when creating a 700 ton launch rocket...

Attempt number 1:

6x RD-215 boosters, 4x RD-107 core stage, 4x RD-0208 second stage, RD-0110 third stage. Total payload to orbit was not 25 tons, since it fell short with that much lead ballast.

Attempt number 2:

The boosters now use E-1s instead of RD-215s for increased power and efficiency, making it capable of reaching orbit with a 25 ton reference payload, if only by the skin of its teeth.

A brief pause to launch an Orange Alphorn Nav, which looks faintly ridiculous with such a tiny second stage:

Not the most rewarding contract ever, but if it unlocks better contracts in future then it's worth doing plus it gets more data units on the relatively new RD-119, which is pretty reliable to begin with.

Meanwhile, over at Venus, can Green Banana V2 break the curse and actually succeed? It has a signal back to Earth, which is already better than the last two missions managed.

Success! Orbit is established and the probe can begin gathering science. But that's not the only aim of this mission...

Dropping the periapsis to 95km, the lander is pointed, spun up and released, then the orbiter re-establishes its orbit.

Venus' atmosphere is particularly vicious- come in too steep and you'll get incinerated, come in too shallow and you'll lose too much ablator and then get incinerated later.

On this occasion I got it just right, the heatshield held up and soon orbital velocity had been arrested. Now all that was left was the long, long descent to the surface.

Spoiler

There were many glitches involved in this descent, since high time warp levels just summoned the Kraken and the trajectory was so flat that at times it had zero vertical velocity due to aerodynamic forces producing lift from the probe core itself. Reloading also caused explosions, so in the end I had to cheat it to the surface (many times, due to even more explosions) because it was getting late and I was tired, and it had taken most of an hour just to get that far so I wasn't about to do it again if I could help it.

After all that, the overpowered antenna and large battery on the lander proved to be overkill as it transmitted all the data it had acquired after just one flyover of the orbiter.

Many funds and many KCT points were the rewards for this mission, both of which will be spent in due course.

But first, back to the 700 ton rocket problem. I realised that I've been looking at this all wrong, comparing different upper stages against each other in isolation and using the same sized tanks for them all (or a double-length version for the RL-10 and RZ.20 hydrolox engines), but there's another way.

Unlike previous efforts, this is a two stage system with solid boosters- eight Algol 2s, to be precise. Five RD-253 hypergolic engines from the Proton but arranged in the Saturn V configuration power the first stage, while the second stage uses the same size of tank but for a single RL-200 hydrolox engine, which performs a long Centaur-style burn to reach orbit. Sharing tank sizes means only one set of tooling is needed, while the second stage can carry the avionics to save costs there too.

Unlike the previous efforts that were carrying 25 ton payloads, with this thing I had a more ambitious target: 35 tons!

A target which was met, just, with the reference payload of lead ballast.

The RL-200 is from CH-4, has TestFlight configs so it has a chance of failure but apparently doesn't have proper tech tree configs for its upgrades, which are mostly increased thrust. At 430s ISP it's better than the earliest RL-10 and at 800kN of thrust it's an order of magnitude more powerful, but it's also very expensive, costing the same as ten of the RD-253s being used on the first stage; again, probably just CH-4 not being fully configured to balance against "proper" RP-1, but the increased payload capacity and shared tooling costs is worth the extra cost of the engine. If I unlock better hydrolox options in future e.g. J-2 then I might swap to those, but for now this seems like the best way forward.

With more tech nodes being unlocked, I also now have access to lunar-rated heatshields including one for Gemini. You know what that means...

It's definitely feasible to do a lunar flyby on a free return trajectory just by putting this thing into low Earth orbit, courtesy of a twin RL-10 lunar stage with some small radiators that make up for the single MLI layer and prevent nearly all boiloff for the short duration of this flight.

The upper stage in that flight could do a TLI burn and a lunar capture, but lacked the fuel to do a return in that case. However, it's only about 15 tons in total including the Gemini and two crew, so my shiny new 700t launch rocket should be more than up to the task of launching it not only to orbit, but most of the way to the Moon as well.

Excess fuel in the second stage was enough to do the majority of the TLI burn, leaving the upper stage with a huge margin to get to the Moon, capture and then return at a later date.

After warping ahead a few days to simulate a lunar landing mission and to check that there wasn't too much boiloff (there wasn't), it was time to try a return.

Lunar Gemini checks out fully. If I can launch a crewed lander out to the Moon on a separate rocket, lunar landings just became a whole lot more practical.

Spoiler

Full album: https://imgur.com/a/oXxBfAX

Coming soon: With 35 tons to LEO on the table, how about some lunar landers? Both crewed and uncrewed designs will be needed for some serious contract money.

[jimmymcgoochie]

The great simulation session begins with a lunar rover, which proved to be pretty stable and hard to topple due to its 10m/s top speed and wide wheelbase. It took actively firing the RCS and doing some reckless braking/steering to even unbalance the thing, so as long as it doesn't end up belly up it should be fine.

Staying at the Moon, sample return time:

The lower section will land on the Moon, grab some samples and then return to orbit, while the upper section will take the sample and return it to Earth.

A few tests were run and issues were found. First, docking:

Lander had insufficient avionics, so I fixed that for the landing test:

Chronic lack of thrust led to impacting the surface at over 700m/s, so a bigger engine was added.

A successful landing (even if it hit the ground at 30m/s and bounced a bit) and still plenty of fuel left over. The combination of one large 2.3kN thruster, four ~550N thrusters with vectoring and four ~550N RCS thrusters with some throttling provides high thrust during the descent, precise speed control for the landing and attitude control without wasting propellant firing the RCS thrusters.

Spoiler

Seriously, if you're playing RP-1 add Coatl Aerospace/ProbesPlus, the 'Jib' thruster is great due to its thrust vectoring ability that no other generic thruster has; the tiny reaction wheels are another useful addition, the Surveyor parts are much better than making your own if you're into historical replicas, and I'm not at all biased by the fact that I wrote an RP-1 config to fix the ProbesPlus antenna costs a while ago 

Back to orbit:

280m/s is a good margin to have, allowing for a rendezvous and docking without the need to use the return stage's more limited fuel supplies. The engines used up quite a bit more MMH than NTO or helium in this sim, so if they use them in a more balanced way then it might have an even bigger reserve. With everything in order, the Blue Violin is ready for construction as the first in the Blue String series.

A real launch interrupts the simulations as Green Banana Mars launches for its transfer window. Ignore the weird blueness on the boosters, I was messing with scatterer settings and clearly got something badly wrong...

Second stage orbital insertion was followed by firing some solid retro-rockets to deorbit the spent stage, while the third stage prepared for the transfer burn to Mars.

The RD-119 provided all of the necessary delta-V to get to Mars, or at least it would have if the transfer burn had been accurate; as it is, a 200m/s course correction will use one of the three ignitions on the Juno 6k upper stage, but that leaves two for the capture burn as well as the probe's own fuel reserves.

Solar panels have been a bit finicky, refusing to work because parts are in the way even though they're clearly not, but I found an angle where the panels could catch the light without being blocked and left it in that position. Sun-tracking solar panels are in a later tech node, but I might have to prioritise that soon.

And back to the Moon for more simulations, but this time it's a crewed lander! Stealing another idea from Terminal Velocity, this lander uses an RD-58 kerolox engine for most of the descent and ascent, while some generic hypergolic thrusters will cover the final descent and any on-orbit burns for rendezvousing etc. as necessary. 

An Astronaut Complex upgrade is required to plant flags, and it's a pricey one; the contract for first crewed lunar landing has a huge advance payment for that exact reason, but it's locked behind crewed lunar flyby and orbit contracts that need to be done first. All Vera can do in this simulation is pick up some rocks and then return to orbit.

Good margins on both the main engine and the hypergolics for a rendezvous with the orbiting Gemini that will form the second half of this mission. With the designs proven, the lunar Gemini receives the name Yellow Glockenspiel while the lander is named Yellow Xylophone. Both will use the same Blue String-class launch rocket and a twin-RL-10 Centaur-esque upper stage to get out to the Moon, but the heavier lander needs slightly larger tanks on the second and third stages to get the necessary delta-V.

This particular sim ended up about 100m/s short of a 50km circular orbit around the Moon, so some tanks were stretched to provide the missing fuel.

Meanwhile in orbit, Orange Trombone 5 has finished its orbital photography and the return capsule is loaded up ready to be dropped back into the atmosphere. Too bad the capsule doesn't have a camera on it, because the views during re-entry were pretty great.

The capsule ended up right in the middle of the rather misleadingly named Hudson Bay, Canada, which is more of an inland sea than a bay. A passing boat fished the capsule out and returned it to land.

And that's the end of the orbital imaging program-

-wait, what? Why do I only have 160 of the 200 science? Did I forget one?

*checks list of active vessels*

Orange Trombone 4, you say? Whoops, I skipped that one. It'll have to wait until next time.

Spoiler

Full album: https://imgur.com/a/Ya4aFS3

Coming soon: Gemini versus The Kraken: Round One!

[jimmymcgoochie]

The fifth of five return capsules, from Orange Trombone 4 (of 5), begins its descent into the atmosphere. A big low pressure system below means it's too cloudy to tell where it's going to end up; all I know is it's flying south-east over much of central Europe.

Dropping through the winter storm, it eventually lands around 50km north-west of Stockholm, Sweden, and is quickly recovered.

Now for a new rocket: Green Fig, a geostationary satellite system. If this prototype performs well enough I'll launch more of them in future for some pretty lucrative contracts.

Well, it got to geostationary orbit, but the fuel margins were pretty thin and future contracts are going to need a lot more than 500 units of payload. Adding more boosters and a better upper stage might make up the difference, but that's a problem for the future.

Contract money means KCT points, currently being split fairly evenly between VAB and R&D so that both build queues are going at the same speed while research keeps advancing.

Significant upgrades have been made to the Yellow Gong since the first flight to considerably boost its available delta-V; no longer will the service module be required to just squeak into orbit!

Orbit was established with a nice 400m/s or so in the second stage, more than enough to raise the apoapsis for the orbital flight contract even with a few days of boiloff.

With the higher orbit reached, the upper stage was detached and deorbited while the capsule remained in orbit for another day.

Contract parameters complete, the periapsis is over Florida right now and the capsule is about to reach said periapsis, so if I time warp around to apoapsis and burn retrograde a bit it should come back down nicely- why are there explosions!?

Activating time warp somehow changed the periapsis from a safe 165km to a suicidal 75km, teleporting the pod deep into the atmosphere. Somehow the capsule survived, though it lost most of its RCS thrusters in the process, and parachuted to a safe splashdown in the Atlantic.

It's not the first time I've almost lost a mission due to a glitch like this: in my last RP-1 career a probe orbiting Uranus lost its communications dish when its periapsis got bumped into the atmosphere and with it any further science; and less than half an hour before this I did a simulation of launching a lunar rover, only to have its trajectory go from skimming the surface of the Moon to not even reaching the Moon's SOI.

Still, all's well that ends well and both Klaus and Vera had some suitably terrifying stories to tell to the two newbies currently in training, the science was gathered and the contract completed.

In between these missions I've been accepting a perhaps reckless number of contracts, many focussed on lunar or interplanetary missions- lunar landing and sample return, lunar rover, do some scans of Venus, several flyby missions of other planets- and I've also modified the Green Banana interplanetary probe to launch a total of four in the next year: Ceres and Vesta were already on the build queue and have now been joined by Jupiter and Mercury; the former has a beefier antenna to phone home from that far away, while the latter is entirely solar-powered instead of relying on RTGs like the others. 

The final launch for today is a Green Cucumber 1.5k, launching into an unusual retrograde Molniya orbit with an inclination of 116.6 degrees. This resulted in some boosters being dropped on western Florida, but I'm sure that's how NASA operates, right?

It seems RP-1 has been changed recently so that certain commercial satellite contracts are mutually exclusive- previously the Molniya, tundra and geostationary contracts blocked and cancelled each other, but now that seems to have been extended to weather satellites too. There's also a 60 day cooldown timer on at least some of those contracts now too, so no more launching rockets every few days to rake in contract cash.

Spoiler

Full album: https://imgur.com/a/31FYyGt

Coming soon: Docking in space and a visit to the Red Planet, hopefully to stay.

[jimmymcgoochie]

Two launches within three hours, a new record. First up was Orange Alphorn DT, for Docking Target.

Launch successful, the second stage deorbited itself while the docking target probe remained in orbit, waiting for the next launch.

When the orbits lined up again, Yellow Gong B1 launched with Klaus and Vera on board (again). Due to the positions of the two crafts, they launched to a higher orbit to allow the docking target to catch up with them.

The B variant has a docking port on the nose, a feature that the A variant does without to save money since docking ports are pretty pricey.

Eight days of phasing orbits later, a small burn from the OMS was enough to set up a nice close rendezvous, passing just 100m from the docking target. Klaus took control of the craft and matched velocities, then began closing in while ground controllers instructed the docking target to turn and face the incoming Gemini spacecraft.

Hard dock achieved. The crew headed out for a photo op, because any excuse for an EVA.

After testing the feasibility of using a docked spacecraft for propulsion (worked, but the docking target's single thruster is too puny to move a Gemini with any kind of urgency) and propellant transfer (also worked, just don't ask about the plumbing...), and with their orbital experiments completed, Klaus and Vera prepared for re-entry. No mishaps this time, just a textbook deorbit burn and service module separation along with undocking the docking target to be destroyed in the atmosphere.

And a safe splashdown in the Pacific.

More science, more money, longer retirement dates and a confirmed orbital docking in May 1965.

And now for something completely substantially different.

Green Banana Ceres is the first of three probes that use only RTGs for power and which are heading out to the asteroid belt (Ceres and Vesta) or beyond (Jupiter). Some compromises were made on the science equipment due to the fact that this mission is only going to be a flyby; orbital capture needs about 2km/s more delta-V than this rocket can manage.

Another flawless launch, followed by an interplanetary transfer burn that was close enough that a mere 10m/s correction burn in 200 days or so will set up a nice close encounter with Ceres. Any remaining fuel will be used to brake into Ceres' SOI to maximise science gains.

The probes for Ceres, Vesta and Jupiter were all retrofitted with improved avionics to reduce their mass and power draw, the latter being the more useful part since RTGs provide a slow trickle of power and the transmitters needed to phone home from the asteroid belt require a lot of power. After the mishaps with the Venus probes, I've adopted a policy of equipping every probe with an antenna powerful enough to get a signal when the target body is at its furthest from Earth- good for getting science data, not so good for power consumption. An upgrade to the Tracking Station is underway which will allow future missions to use less powerful and power-hungry transmitters.

Spoiler

Full album: https://imgur.com/a/cV9D9Wh

Coming soon: Lunar relays and a Martian arrival.

[jimmymcgoochie]

I keep accepting contracts to get more money, without really thinking about when the contracts are going to be due, how to complete them or how long it'll take to make the vessels to complete the contracts. I'm expecting to end up in a situation where I have to deliberately let some contracts fail in order to fulfil the rest, which is far from ideal.

But anyway...

Green Guava is a set of three relays heading to the Moon in order to provide communications coverage to the far side. There are contracts for far side lunar landings and the first lunar rover contract I picked up has its target sites on the far side too, so this launch will help to support future missions. Each relay also carries some science experiments to get as much science as possible from a polar lunar orbit.

Polar orbit also gives some nice Earth/Moon shots.

Not the neatest probe decoupling ever, but so what? After braking into a 2/3 resonant orbit, the upper stage is deorbited using RCS, since all three ignitions on the Juno 6k have already been used, while the relays themselves set up for circularisation burns at successive apoapses.

Unlike the relays in Earth orbit, I went to the effort of fixing the Green Guava relays' orbital periods to be almost exactly the same- 9 hours, 30 minutes and within a hundredth of a second of each other. The orbits aren't perfectly circular, but a nice neat orbital period was more appealing (and easier to remember) and the relays can all talk to each other.

A little while later, Green Banana Mars arrives at its destination:

A quick jaunt over to Mission Control later...

The orbit is well off the plane of Phobos' orbit, however the ascending node is almost directly on top of said orbit and it should be possible to get a flyby relatively cheaply in the future even with Phobos' tiny SOI. No capture burn though, the gravity is just too weak and orbital velocity is about 6m/s.

More interplanetary missions have yet to be launched. First up, Green Banana Vesta:

Despite having to sort through eighty screenshots for this update, there aren't any of the transfer burn. It worked reasonably well, if a little bit inaccurate, and a small course correction in about half a year will send it hurtling past Vesta at considerable speed.

At last, newbies Robin and Patrick are ready for their first mission! Yellow Gong A4 (or should it be A3?) will complete the low Earth orbit crew science experiments and go for a 14-day endurance record, simulating a lunar flight.

Another flawless launch thanks to incredibly reliable Soviet engines all around. Robin and Patrick headed out for an EVA and photo op before settling in for the two week mission.

Gemini capsules aren't exactly spacious, though, and by the time the 14 days were up both crew were getting very stressed. Time to come home.

Mission accomplished, loads of funds gained and a significant amount of science transmitted too. Robin and Patrick clearly enjoyed that mission, since they've both decided to stick around for another three years:

And now for the debut of the new Blue String class 700 ton rocket. This first mission is Blue Violin 1, a lunar sample return mission.

As with most designs using brand new engines, not everything went entirely to plan:

The failure happened about ten seconds before MECO though and made no real difference, but gained some reliability data for the RD-253 which is good. The second stage engine- an RL-200- worked perfectly for the rest of the ascent. And then promptly failed to ignite for the TLI burn despite a 95% ignition chance.

Almost 2500m/s of delta-V remaining in that second stage is now gone and lunar return is gone with it. However, it might still be possible to land the lander on the Moon and get some science out of it. Using the braking stage to start the TLI and draining the return section's fuel to run the lander's engines to finish it got the job done, but it wasn't pretty or efficient.

This lander has a pretty low TWR and due to time warp bumping the lunar periapsis into the surface it's going to be a pretty steep direct descent trajectory, so this could go badly wrong-

 "Landing" speed of 200m/s was clearly unsurvivable and the avionics unit that broke off crashed a few kilometres away and was destroyed. If there's a silver lining, it's that the engine failures of this mission made the engines more reliable for the next attempt.

Another Green Banana, this one headed to Jupiter.

A recent update to RO or RP-1 has disabled the stock delta-V tool entirely, which has the unfortunate side-effect of making the stock 'warp to node' button warp to 1 minute before the node regardless of the real burn time, resulting in a lot of late burns and the inaccuracy that comes with it. Jupiter's SOI is so huge that it doesn't really matter, but the burn to Jupiter used up all of the RD-119 third stage, all of the Juno 6k upper stage and a significant part of the probe's own fuel. Clearly Saturn is out of reach with this design.

The trajectory to Jupiter got a small tweak with a course correction just after leaving Earth's SOI, setting up a nice close pass over Jupiter itself that might allow an orbital capture, though the resulting orbit would take more than an Earth year and would deliver minimal additional science or opportunities to fly past one of the moons.

Course corrections were also performed for the Ceres and Vesta missions, bringing their closest approaches down.

And now for the first rover of this playthrough- Green Huckleberry 1, heading to the Moon's far side. A last minute upgrade added additional science experiments that had just been unlocked, though that also upset the weight balance a bit and made landing it a bit harder.

The braking stage was enough to almost stop the rover dead over the surface of the Moon, but the unbalanced centre of mass combined with a relatively low TWR made the landing itself a bit dicey.

I designed this rover to be able to recover from this, though, and sure enough...

Back in business! No damage to the solar panel either. There's a lot of science that could be gathered from the landing site, but the contract is the top priority and science can wait until later. This landing also completed a lunar landing contract, though not the more lucrative far side landing- I didn't check where the rover sites were or I would have taken that one instead.

Chasing all these contracts meant that I missed the optimal time for the Venus transfer window, so Green Ilama (not llama, ilama) is launching late and chasing an ever-narrowing opportunity.

It might not be able to make it into an orbit that's usable for the radar altimetry and biome scans it's being sent out to do, but should still be able to gather a lot of science. The next transfer window is over a year away, so plenty of time to build another if this one doesn't work out.

Over at the Moon, Green Huckleberry 1 arrives at its destination and makes a tidy profit:

The last interplanetary probe for a little while is Green Banana Mercury, which I really hope avoids the glitch that ruined my first Mercury mission in my last RP-1 career.

The combination of RD-107/RD-108, RD-0110 and RD-119 is so reliable now that the chance of engine failure is almost zero for the launch; the Juno 6k is still the weak link with just 93% ignition chance, a number that's unlikely to improve much more. A course correction shortly after departing from Earth sets up a nice close encounter with Mercury:

Let's just say that this is definitely a flyby...

And now for the final launch of this report- Blue Violin 2, aiming to succeed where its predecessor failed. There's just enough time to build a third one before the contract expires, but hopefully that won't be necessary.

No failures this time!

Lunar capture was complicated by yet more periapsis bumping whenever time warp was switched on, resulting in most of the upper stage's RCS propellant being used up repeatedly fixing its course, and then the warp to node button overshooting again. It took all the remaining ignitions on the upper stage just to capture into a 50km circular orbit, where the return probe detached and pointed its solar panels to the sun while the lander backed off and prepared to land.

But the landing itself will have to wait until another time!

Spoiler

Full album: https://imgur.com/a/Hhcroa0

Coming soon: Finishing the lunar sample return mission and maybe a crewed lunar flight in 1966?

[jimmymcgoochie]

Time to land the Blue Violin 2 sample return mission.

Unlike its predecessor, this one landed softly and without any damage. Science is a-gathering, so the lander will wait on the surface for a month to get as much data as possible and to allow the orbit of the return craft to line up again. 2.3km/s of delta-V should be more than enough to get back into orbit and do the rendezvous and docking after that.

Still on the topic of the Moon, Green Huckleberry 2 is heading there now:

250 tons of rocket to put 250kg of rover on the surface of the Moon. Pesky rocket equation.

A safe landing- on the wheels, no less!- and in a new biome too. There's almost a whole year left on the rover contract, so it'll stay put and get more science for now before driving almost 4000km to the waypoints for that contract.

Science coming back from the Moon and Mars (and possibly Venus too) means lots of free KCT points, which were duly spent.

I'm keeping some cash in reserve as there will no doubt be a lot of mission designing going on in the near future to complete some of the many many contracts I accepted recently. Meanwhile, I keep bodging new vessels out of existing designs to eke out more science:

The Orange Alphorn Docking Target worked out well, so here's another Orange Alphorn-derived probe- the Orbital Science version, carrying all the new experiments into a highly inclined and elliptical orbit of Earth with an apoapsis of just over 100Mm. There's plenty of science to be had from high Earth orbit and this thing should slowly gather most of it.

A brief design session produced this:

Essentially the same avionics unit as the probe above, but outfitted for landing on Mars instead with a parachute to slow it down to a reasonable speed and RCS thrusters for throttleable thrust for the final descent. The first test proved successful, deorbiting from a low Mars orbit and landing safely with a bit of a lifting re-entry for good effect, however it lacks such frivolities as 'science experiments' and 'solar panels' so there's still work to be done.

Spoiler

Full album: https://imgur.com/a/FyJgYdw

Coming soon: Not much for the next week and a bit, I'm finally getting a proper break after Covid cancelled my Easter plans.

[jimmymcgoochie]

I leave for a week and there's a dozen mod updates waiting for me when I get back. Hopefully none of them will break this save... 

[jimmymcgoochie]

Good news- save is not broken.

Good-er news- Parallax!

Blue Violin 2 launched about a minute too late for a direct rendezvous, mostly because I forgot the orbiting return probe was in a retrograde orbit and so misjudged the launch time. A couple of orbits later, it approached its target and-

Hang on...

WHERE'S THE DOCKING PORT GONE!?

*one short burst of cheating later*

Ah, there it is.

Spoiler

After reviewing the earlier reports, it seems that at some point between capturing into orbit and sending the lander down, the return craft's docking port disappeared and I didn't notice at the time. I only realised this after cheating a new, fixed return craft into orbit beside the old one though as I thought it was some kind of update-induced glitch at first.

The return craft took the sample and then headed for Earth at the next opportunity, leaving the lander in orbit to gather what science it can.

Those craters are definitely a lot more pronounced now thanks to Parallax.

A successful, profitable and scientifically valuable mission all around. The design has been demonstrated and more will be launched in the near future, at least until the crewed landings start- hopefully in 1966!

A couple of months go by and science keeps coming in, giving more free KCT points and so more upgrades.

A change to the Blue String rocket was tested, swapping out the solid boosters for a sixth RD-253 and stretching the tanks slightly (from the minimum possible within tooling limits to the maximum) which will reduce costs without impacting performance. The current design overburns the engines a bit, but this new one doesn't which should also reduce the chances and impacts of failures.

It's almost a Proton first stage at this point, though no Proton ever used a huge hydrolox stage on top. This "Block 2" Blue String will be put into service for all future missions, except for Blue Violin 3 which was too close to completion and so went ahead with the old design.

The launch went flawlessly- or so I thought...

By the time it got to orbit, something was way off in the numbers. The RL-200 engine had suffered a performance loss, its ISP dropping by about half and taking the thrust and delta-V with it, ruining this mission's chances of success. By burning the rest of the second stage for what little it could muster, then the third stage, then some fuel from the lander itself and dumping the return stage after draining its tanks, Blue Violin 3 might be able to limp to the Moon's surface- and stay there.

This failure isn't quite as bad as Blue Violin 1, but the RL-200 has caused problems on two of the last three Blue Violin missions despite its relatively high (claimed) reliability. I might switch to the J-2 if the numbers stack up in its favour.

While that mission was en route to the Moon, Green Ilama 1 arrived at Venus. As expected, there was insufficient fuel to circularise into the low orbit required for scanning, with an apoapsis of just over 2Mm when the scanners can only manage 500km and 1000km at most, but it's not as bad as it could have been and the radar altimetry contract only requires 25% coverage, which this orbit should be able to achieve.

One contract completed just by making orbit, with at least one more still to come. A future mission will still be needed to complete the other scans and to deploy a lander (and maybe even a rover?) to the surface, but the next transfer window is still a while away.

Final scores:

Green Jackfruit 1 is just the return craft part of the Blue Violin missions attached to the same rocket used by the Green Apple lunar relay mission; if Blue Violin 3 can land and return to orbit, it'll get launched to send the sample back, but if not then it might end up as a docking target for Yellow Glockenspiel 1's crewed lunar orbit flight.

Spoiler

Full album: https://imgur.com/a/mEjwX0B

Coming soon: I should probably check the upcoming transfer windows and active missions, then design new vessels accordingly.

[jimmymcgoochie]

Time for an exercise in making the best of a bad situation- Blue Violin 3 is approaching the Moon.

A successful capture burn later, the lander has around 4km/s of fuel left. Orbital velocity is a smidge over 1600m/s, so on paper it's possible to land and return, but paper doesn't have to deal with gravity losses from the low TWR.

While waiting for the far side to rotate into daylight, I tried to launch another tundra-orbit contract sat, only for a strange issue to rear its head:

As soon as the boosters separated, the core stage's RD-108 engine exploded. I have no idea why this happens as this is the same design that's launched many times before without incident, so I blame mod updates. The design (and others like it) were modified so the boosters are slightly further out from the core, which seems to have solved the issue.

Blue Violin 3 then made its landing attempt.

A successful one, yes, but using far more fuel than anticipated. Returning to orbit clearly isn't feasible, and worse, it's landed in a biome that's all scienced out already.

However... there's a lot of fuel still in the tanks and a different biome off to the south-west.

One biome hop later and some science is coming in; alas, this biome has also been visited before by a lander or rover as some of the science is done already, but there's still plenty left to get.

There's a very tasty contract sitting in Mission Control that wants a space station in LEO and has a 2 million fund advance payment. Coincidentally, I've just unlocked the first space station parts node. You can probably see where this is going...

Tacking an entire Yellow Gong on top of the station gives it a bit more habitation space, more supplies and a viable escape option if something goes wrong. The station will be fuel cell powered as solar panels aren't advanced enough yet to run this thing effectively, but there are a number of crew experiments in the small science module and a little lab to process samples, so this station might actually be useful for more than just contract cheese.

It was only after the simulated launch had reached orbit that I realised the Gemini's avionics can only handle 15 tons, whereas this station is close to 20. There are also no docking ports. And a few other minor issues to sort out as well. But that's what simulations are for!

A few days later, Green Banana Vesta is approaching its destination.

A course correction was required due to orbital drift, but then I noticed the closest approach on the next orbit was really close to Vesta. A bit of node fiddling later...

A burn to set up a flyby of Vesta, happening during a flyby of Vesta! A completely coincidental 1:1 orbital resonance which will allow more than one flyby from the same mission and hopefully a lot more science too!

This is fine.

Encounter number 2 is set up before the first one is finished, with the potential for even more flybys in the future if the small fuel reserves can be stretched that far. I've never seen anything like this before, it wasn't planned at all and the course correction that I did after loading the vessel could probably have been tweaked to make this second flyby even cheaper.

Spoiler

Full album: https://imgur.com/a/mAVZCNd

Coming soon: Crewed lunar orbit?

[jimmymcgoochie]

Brief update: I tried to make the avionics on the RoveMate probe core toggleable to make the two Green Huckleberry lunar rovers able to function properly, since even with the sun directly overhead the solar panels can barely charge the batteries at all due to the avionics constantly running and using a lot of power.

Long story short, it took two days and reinstalling a lot of mods to undo the damage and make the RoveMate reappear in the parts list. Probably should've tried this in a different copy of KSP than the one I'm doing this save in... 

[jimmymcgoochie]

Only one mission to report, but it's a pretty important one: crewed lunar orbit!

Things initially looked like they were going to plan, but then I realised the avionics on the third stage had been tampered with- instead of RCS propellant, it was full of batteries! I suspect a change to the avionics type reset the tanks at some point and I didn't notice; fortunately the excess weight made no difference and the Gemini service module had plenty of excess propellants in it to use for RCS.

A nice low orbit of around 50x50km was established and the crew set about doing Science!^TM and other important things. But mostly Science!^TM

Until they tried to do EVAs and discovered that they'd left their EVA jetpacks at home. Fortunately for all, this was discovered before letting go of the pod and floating off into space.

After two* days in lunar orbit, the Science!^TM was done and the contract parameters were fulfilled. Time to come home, much to Robin and Patrick's dismay.

Spoiler

It was probably a lot more than two days due to timewarp not stopping when I told it to, but the life support supplies are overprovisioned in case of emergencies.

An advanced biological sample experiment was run on the way home, bagging even more data from space high above Earth, before the crew jettisoned the upper stage, service module and re-entry pack and got ready for re-entry.

Re-entry was... Terrible. There's a bug with a number of pods in ROCapsules that makes their maximum skin temperatures incredibly low and deviating from surface retrograde by any more than one degree resulted in instant explosions. It took a few reloads before I found this out and managed to get the pod through the atmosphere intact.

And Jakarta was added to the list of "major cities that I've dropped returning spacecraft on (or near)" as the pod came down on the outskirts of the city, no doubt making air traffic controllers' lives a lot more difficult.

A safe parachute landing later and the funds started rolling in.

Of the 892.5 science, I'd estimate that at least 500 of it came from this mission- crew experiments in space high around Earth and both high and low around the Moon were transmitted back in flight- and the rest came from orbital probes around Venus and Mars(?).

Spoiler

Full album: https://imgur.com/a/SzkFtW3

Coming soon: CREWED. LUNAR. LANDING.

[jimmymcgoochie]

With a Mars transfer window approaching, it might be a good idea to send something in that direction- but first I need to design it. I have an idea for an ambitious cluster mission to send landers to Mars and probes to both Phobos and Deimos.

The design for the Mars lander initially used airbags to soften the landing, which proved unreliable both for absorbing the impact and for landing right side up.

Switching to tiny landing gear, as for the Moon landers, fixed that problem.

Launching two of these landers along with two probes to visit Mars' moons proved to be too much even for a new Block 2A version of the Blue String rocket; while it could make it to orbit and probably to Mars, it wouldn't have any fuel left to try and capture into orbit.

While the upgraded launch rocket isn't powerful enough to throw the better part of ten tons at Mars, it proved useful later thanks to the extra oomph from the six Algol 2 solid boosters.

Before the crewed Moon landing can occur, a rather different vessel is heading to the surface of the Moon: Green Huckleberry 3, an improved Moon rover.

The rover itself has been upgraded with better power generation to compensate for the high power drain of the rover's avionics* and its rocket has replaced the Juno 6k with a more reliable and efficient AJ-10 Advanced**.

Spoiler

* Despite my attempts to tweak it, I couldn't get the RoveMate's avionics to be toggled and only broke the entire install for a while until I reinstalled many mods to fix it.

** TestFlight lost all the data units on the Juno 6k, probably because of reinstalling so many mods, which made it rather unreliable again. The AJ-10 Advanced is far more reliable, has a higher ISP, more thrust and infinite ignitions.

Despite attempting a reasonably targeted landing near the rover waypoints, it ended up coming down almost 1000km away from them. The power upgrades came into their own at that point, allowing a much faster rate of travel across the lunar surface than the previous rovers while still running all the science experiments and transmitting the data back to Earth.

It didn't take long to reach the waypoints, complete the contract and then set a course for a new and as-yet unexplored lunar biome to get even more science.

Back to the Blue String Block 2A for the launch of Yellow Xylophone 1, the crewed lunar lander that will take one lucky Kerbal to the surface of the Moon- and back! This vessel had some last-minute upgrades applied including the addition of solar panels and extra propellant, while the rocket was upgraded to the Block 2A configuration to give it a bit more oomph off the launchpad.

Less than five days after launching, the lander is in a stable orbit around the Moon and awaits the crew's arrival. Pointing the solar panels at the sun also means the fuel tanks are facing away from it, which should reduce boiloff of both the propellants and fuel cell fuel.

The crew launched a few weeks later than the lander, partly because there's only one launchpad that can handle the weight and partly because the Astronaut Complex upgrade is still in progress and must be completed before the landing attempt is made.

As dawn rose on the 23rd of September 1966, Klaus and Vera boarded Yellow Glockenspiel 2 and prepared to head to the Moon. Following the no-jetpacks fiasco of Yellow Glockenspiel 1's mission, extra care was taken to ensure that both astronauts had their EVA packs with them.

The Gemini craft is significantly lighter than the lander so no solid boosters are needed, however a minor change has been made- the RL-10 engines were adjusted so their thrust was aimed closer to the centre of mass, potentially allowing some control if one engine failed.

As the crew approach the Moon, they begin their science experiments and take some nice pictures.

A carefully planned capture burn and a tiny course correction allowed them to rendezvous with the lander after a single orbit.

Rendezvous and docking took place in the dark. As is right and proper. The final approach and docking took place just as Earth rose over the lunar horizon, allowing pilot Klaus to pop out for a publicity shot. Or at least that's what he said he was doing...

With the critical building upgrades complete...

The landing can commence! Or rather, it could commence, if it wasn't for the fact that the entire near side of the Moon is currently in darkness. The crew have ample supplies for an extended mission and propellant boiloff is well within safety limits, so they settle in for a ten-day wait to let the Moon's near side rotate back into daylight.

Klaus won the (literal) coin toss and so got to fly the lander to the surface while Vera waited in the orbiter above. The chosen landing site was Mare Crisium, which has already been visited by a probe lander but which fell directly under their orbit and has a large, flat expanse that's perfect for landing on.

Once you clear the mountains on the eastern edge, that is.

The lander's main engine- another last-minute upgrade- performed most of the braking towards the surface, but also used up three of its five ignitions during the descent after Klaus stopped the burn slightly too early and the hypergolic thrusters couldn't slow him down in time before hitting the ground. Despite this minor mishap, the landing proceeded smoothly and Klaus touched down gently on the surface on the 8th of October 1966.

Time to do that "first small step" thing.

Alas, the stay on the Moon would be short- Klaus tried to be clever and adjust his landing site to the north to try and be under the orbiter's orbit when it was time to leave, but this actually had the opposite effect and he should've gone south instead. If he waited too long, the rendezvous could become prohibitively expensive. Less than two hours after landing, Klaus lifted off again and headed to orbit.

A bit of skilled piloting put his trajectory on course to rendezvous directly with the lander, combining the orbital insertion and velocity-cancelling burns into one.

With the return window rapidly approaching, the crew transferred all usable supplies and propellants from the lander to the orbiter, undocked the lander and sent it down to crash into the surface. The lander's design may one day allow it to be developed into a fully reusable one, but for now limited ignitions mean they're single-use only.

It's a quick five day trip back from the Moon and the crew gather even more science on their way home before strapping in for re-entry. Getting even one degree out of alignment could spell disaster at 10 kilometres per second, but the well-trained crew know exactly what to do and paint a streak of fire across the Sahara desert from Tunisia all the way to Saudi Arabia.

A safe landing, despite the extra weight of Moon rocks causing the capsule to hit a bit harder than usual and destroy the heatshield in the process, and the contracts pay out.

Much funds? Check. Much science? Check. Much retirement delays? Check. All in all, a complete success!

So naturally I decided to do it all again for even moar much funds, science etc. etc.

With the VAB now fully upgraded, a significant investment was made to boost the third build queue's speed, however most of the funds went into R&D, both in KCT points and in another facility upgrade. All available nodes have already been queued at this point and the research rate is going to be the limiting factor for a while.

Spoiler

Full album: https://imgur.com/a/qFEQaAz

Coming soon: Mercury and Mars transfer windows await, while a space station lurks on the build queue awaiting its chance to fly and more as-yet undesigned missions will need to be prepared.

[jimmymcgoochie]

After some experimenting, I've come up with a new plan for the big Mars mission: remove one of the moon probes and push right up to the 700 ton weight limit to maximise delta-V.

One of these is already under construction, with a second added to the build queue when I checked and found out that the real Mars transfer window is actually a lot later than KAC said it would be.

Another upgrade to the Blue String rocket, the Block 2B features uprated RD-253-Mk2 engines which provide noticeably more thrust. First to test this new config is Blue Violin 4 on its way to the Moon:

The probe captured into a nice low orbit of the Moon, however the entire near side is in darkness right now so it'll have to wait for a while before landing. The return probe was detached and left in orbit while the lander waited for the right time to land, mopping up some low orbit lunar science in the process.

While waiting for the Moon to spin around, Green Banana Ceres arrived at its destination. No flukey resonant orbits with this one, just a single flyby, so it used up most of its remaining fuel to slow down as much as possible to maximise the time spent gathering data.

A Mercury transfer window is opening and two probes will be sent there- Green Banana Mercury 2 and 3, both flyby probes since capturing into Mercury orbit is ridiculously difficult. 2 will launch now, while 3 waits a little longer.

Everything worked as planned thanks to the very high reliability on all the engines and the probe is on its way to Mercury now. Capturing would take another 8km/s, which this probe doesn't have.

With all the science coming in and some big contract payouts and advances, the third VAB queue is now up to the same speed as the first two:

Future KCT points will mostly go into R&D to unlock new technologies faster and try to keep those VAB queues busy.

Spoiler

Full album: https://imgur.com/a/jvmBHML

Coming soon: Mercury and Mars missions and possibly the launch of a space station.

 

 

[jimmymcgoochie]

I think this is the launch of Blue Violin 4 to the Moon, but honestly I can't be sure. It might be some super-secret prototype that I was testing and just forgot about between then and now.

Given that the next screenshots after this are of Blue Violin 4 going to the Moon, I'm going to assume that this is it launching.

The upper stage had to be discarded with a significant amount of fuel remaining because the lander's TWR is so low when fully fuelled that it can't actually land safely without burning off a lot of fuel first. A flaw that I may correct in future, if I decide to launch any more of these missions.

With that lander on the surface I took some time to cull the craft list, discarding debris, dead probes and missions that just didn't work any more. One that survived the cull is Blue Violin 2's lander, now in orbit of the Moon, which got its orbit adjusted to get even more science.

With transfer windows approaching and contracts available, I did a burst of mission designing: a Venus mission adapted from the Blue Guitar multi-probe missions and fitted with four Venus-spec landers; a Mars rover based on the Green Huckleberry Moon rovers but with a skycrane above the rover instead of a landing stage under it; and an upgraded Green Cucumber contract sat launcher that can carry 2000 units of payload and is only marginally more expensive than the existing 1500-unit design.

I've also had a rummage through the newly unlocked parts and configs to see if there are any upgrades I can make to existing designs. A few show promise, but aren't yet finalised so aren't ready to be shown off yet.

Following a month-long stay on the surface, Blue Violin 4's lander returned to orbit and docked with the return probe within twenty minutes of lifting off.

With the return probe's tanks topped up and batteries recharged, the lander undocked and remained in lunar orbit while the return probe set a course for home with the precious sample on board.

Interrupting Blue Violin 4's return was Green Banana Mercury 3, launching into the optimal Mercury transfer window.

Yet another engine has mysteriously lost data units- the RD-0110 in the second stage has dropped to a little over 2000du when it used to have the full 10k, though reliability is still very good and no problems occurred on this launch.

And a few days later Blue Violin 4's return capsule blazed a trail across the mid-Atlantic sky as it re-entered, enduring some pretty brutal deceleration of up to 15g as it did so.

A successful mission, and a vital injection of much-needed funds which were getting critically low:

Three missions are currently under construction for the upcoming Mars transfer window, a fourth for Vesta and another for Venus; there's also a space station partially built and awaiting its turn in the VAB again and a Ceres mission at the back of the queue. A second lunar landing is also on the cards at some point with both parts also on the queue, while a crewed LEO Gemini will be needed to visit the station and complete that valuable contract. That should keep the VAB crews busy for a while.

Spoiler

Full album: https://imgur.com/a/t3QI3q7

Coming soon: A bit more design work, possibly a geostationary contract sat and the first launches to Mars.

[jimmymcgoochie]

Making a geostationary contract satellite wasn't as difficult as I thought it would be- a three-stage 350 ton rocket is enough to put 2000 units of payload into GEO orbit with plenty of fuel left to get to a specific longitude.

With that design completed, it's time for some real missions as 1967 begins with a Mars transfer window. Montage!

Green Kiwi 1:

The second stage engine was swapped from an RD-0110 to an RD-0213 which provides a lot more thrust, something that future missions using the three-stage setup will copy. I had to angle the rover so that the skycrane wouldn't block the solar panel, but it seems to be working well enough.

Blue Guitar 1:

Staggered staging on the solid boosters didn't work, the second trio were still burning when the first stage ran out of fuel and had to be dumped. The transfer burn took about ten minutes in total and required a significant amount of off-plane burning, which required a significant course correction burn to get on course for Mars. I may have to drop the landers early and hope they can survive a direct descent.

Green Kiwi 2:

Launching later in the transfer window than its sibling, this mission will take a slower but lower-energy route that should leave it more fuel to slow down before hitting the atmosphere. Only requires a small course correction, unlike the other Mars-bound missions today.

Blue Guitar 2:

The transfer window was more favourable for this Blue Guitar, resulting in more fuel remaining and a smaller course correction to compensate for the looong transfer burn.

Spoiler

Maybe this is (at least part of) why the game is laggy at low altitudes?

That's an impressive smoke trail...

And following close behind all those was Blue Mandolin Vesta. No fancy multiple probes on this one, just a single orbiter that should make it to low Vesta orbit and transmit a whole heap of science.

In between all the launches, Green Bananas 2 and 3 had their own course correction burns to get on course for low flybys of Mercury.

Both probes will arrive within a few days of each other and scrape up a lot of science. I think I might try to get a second flyby with one of them to increase the science gains, though it might be difficult to do so.

Spoiler

Full album: https://imgur.com/a/ye6aWXm

Coming soon: With the interplanetary stuff out of the way for a little while, it's time to focus on crewed missions again: an Earth orbit space station and a second crewed Moon landing. Better get those astronauts trained up again...

[jimmymcgoochie]

Wow, has it really been that long since I posted here? I have three whole Imgur albums waiting to go...

This might be the last Blue Violin lunar sample return mission I launch, and the last uncrewed lunar return mission too. The contract payments are nice, but they'll inevitably run out, while the science gains aren't that great over sending a rover to drive around and get better science from more biomes.

A few minor upgrades to the design (mostly MOAR ENGINES) give the lander a higher TWR, meaning it can put the upper stage's remaining fuel to good use instead of throwing it away.

I aimed for the Oceanus Procellarum, the largest of the Moon's "seas" (so big that it's an ocean, in fact). So obviously I managed to find the one crater for many miles in all directions and aim right for it.

The crater walls were steep, but the floor was relatively flat and smooth and landing wasn't difficult. The lander will stay in place for a while to gather science data before launching back to meet up with its return probe next month.

While that mission was waiting, Blue Guitar 1 made a course correction burn to set up a Mars encounter. There should be enough fuel to capture into some kind of orbit, but what that orbit looks like and how many of the probes on top make it to their targets remains to be seen.

From Mars to Mercury now with a twin flyby: Green Banana Mercury 2 arrives a few days before its sibling and finally completes the flyby contract (that the first mission technically completed but the game didn't register it because it was in the background, probably) for almost million funds.

This flyby was almost too close...

The velocity at periapsis was over 14km/s, even after expending almost all the probe's fuel to slow down after entering Mercury's SOI. So naturally I get offered contracts for Mercury orbit, landing and rover.

Mere days later Green Banana 3 flies by too, forsaking the braking burn in exchange for a potential second flyby in a few years' time. Worth a try, right?

Green Banana Vesta also got in on the course correction action, setting up its encounter with Vesta with enough fuel left to capture into orbit. This time I'm almost certain of it.

And now for something a bit more substantial: Yellow Timpani 1, the first space station.

So what if it's a couple of cheap crew modules with a Gemini pod and service module stapled to the top? At least the crew would have a means of escape if something went wrong with their own capsule.

Placed in orbit, a problem quickly revealed itself: avionics. It can't fly itself, let alone with a multi-ton Gemini docked to it as well. Oops.

 

But not as big an oops as what happened next:

Check your staging, boys and girls! Make sure the launch clamps release all at the same time instead of one rogue clamp detaching with the booster separation stage. Not the first time that particular issue has cropped up, but the first time I haven't noticed it until too late.

Let's try that again...

Much better!

Docking to a target that has no control and is ever-so-slightly spinning isn't easy, but the crew got there in the end and took up residence in their new home for a month or so.

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The lack of control, together with a lack of water generation because I put huge solar panels on it and they're producing too much power for the fuel cells to produce the needed water, means this station will need an upgrade before more crews can visit.

However, the science stuff still works fine and the lab inside the experiments module can process samples, leading to some weirdness with the synoptic terrain and weather photography experiments actually generating samples out of thin air as they're processed. I saw this during the crewed Mars and Venus missions in Terran(ism) Space Program and apparently it still hasn't been fixed. Oh well, more science for free I guess .

Back to the Moon and Green Huckleberry 4 is launched to become one of two active rovers on the lunar surface (the first two are now officially dead due to chronic power shortages) and pick up a nice contract along the way.

The flight to the Moon went fine, but the landing site is a) way out of alignment with the rover's orbit and b) in the dark, so landing will have to wait.

On the other hand, Blue Violin 5 has both daylight and orbital alignment, so lifts off from its crater and heads back to orbit.

The samples are transferred over to the return capsule, which quickly plots a course back to Earth leaving the lander in orbit to collect what scant science remains there.

The rest was routine.

Final scores for this report:

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Full album: https://imgur.com/a/rrsDwR9

Coming soon*: Rover to Moon, station crew to Earth and the final evolution of the Green Banana.

* No, really!

[jimmymcgoochie]

Green Huckleberry 4 has waited patiently in lunar orbit for the landing site to be both in daylight and vaguely near its orbit. Time to land.

*ahem* That whole "landing upside down and having to roll side to side with the RCS to get the right way up again" was not the plan; stupid MechJeb tried too hard to chase the retrograde marker and ended up landing at an absurd angle, which would have been survivable if not for some minor wheel weirdness causing it to suddenly pivot over onto its back. No harm done though and it's driving towards the contract waypoints now while scraping up all the science it can.

Staying with the theme of landing on the Moon, it's about time I put another pair of boots on the ground up there. Much the same as last time, it'll be a two-launch, lunar orbit rendezvous deal and the lander, Yellow Xylophone 2, is up first.

During the trip I noticed that the upper stage's avionics was wrong: instead of holding RCS propellant, it was full of batteries which just added a load of unnecessary weight and required some propellant to be stolen from the lander itself in order to get there. I thought I'd fixed that...

It'll be a while before the crew can launch, during which time a few things need to be taken care of. First up, a heavily modified (in more ways than one) Green Banana probe was designed to be launched all the way to Saturn; it only just scrapes under the 350 ton weight limit and should have just enough fuel to make it to a flyby trajectory of Saturn. Assuming it doesn't do what it did in the simulated launch and end up burning vertically up because MechJeb made a right mess of the launch.

Trying to get the necessary delta-V without straying over the weight limit or ruining the TWR on the pad was tricky, but I think I got there in the end. Assuming MechJeb can fly it properly, it should be more than adequate for the trip out to Saturn.

A few days later and the crew of the Yellow Timpani space station have been in orbit for thirty days. Thirty days of continuous tumbling due to the lack of avionics control, constantly short on water as the solar panels produced too much power and the fuel cells didn't run, yet the experiments still got completed and partially processed in the experiment module's little lab.

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As with my previous RP-1 game, the synoptic terrain and weather photography experiments managed to replenish their samples faster than they were used as long as they were being processed by the lab. Weird. Free science though, they're supposed to take three launches to complete but I got them in one.

Time to come home.

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During this re-entry I discovered something weird with the centre of mass shifter in the Gemini pod: it was shifting the CoM the wrong way.

It's supposed to pitch up when the CoM shifter is engaged to allow a lifting re-entry, but instead it pitched down and made the G-loads even higher.

A safe splashdown in the Gulf of Mexico and the contract paid out.

Not to mention the science:

And a bunch of free KCT points, which were spent on R&D to unlock the new stuff faster.

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Full album: https://imgur.com/a/jSDENRj

Coming soon: Moon landing #2!

[jimmymcgoochie]

With a 700 ton launchpad I've put boots on the Moon (and the rest of the crew too; walking in low gravity isn't easy!), but it took two launches spread two weeks apart. 700 tons is enough to get a fairly simple orbital probe out to Jupiter or a sizeable cluster mission to Mars or Venus, but to go to more exotic locations- and in a reasonable timeframe- size matters.

Which is a long-winded way of saying I bought a 1500 ton launchpad. Construction should finish in about 60 days, give or take.

Back to that whole 'Moon landing' thing and Yellow Xylophone 2 arrives safely in lunar orbit to await the arrival of the crew for this second Moon mission.

As soon as the rollout is complete, Yellow Glockenspiel 3 launches to join it. Robin and Patrick have already orbited the Moon on the Yellow Glockenspiel 1 mission, but this time one of them gets to land on it.

During the TLI burn I noticed a potentially major problem: the upper stage avionics was supposed to have RCS propellant in it, but some kind of configuration mixup has filled it with batteries instead. I don't need the power, batteries are pretty heavy and now the RCS has to steal propellant from the Gemini service module's (admittedly sizeable) reserves instead. I thought I fixed that...

Lunar arrival went without further trouble, with convenient timing and a well-planned capture burn allowing for a rendezvous with the lander within a single orbit.

Once docked, Robin (who won the impromptu rock-paper-scissors face-off) headed over into the lander to begin her landing attempt.

Spoiler

And crashed.

Firing the hypergolic thrusters far too late to slow down in time, the lander hit at about 30m/s and smashed the landing legs and main engine. Oops.

Each mission gets a reload though, so I reloaded from the two vessels docked, undocked and landed perfectly. But then I noticed there was nobody inside the lander.

Apparently I saved before doing the crew transfer and then forgot about it. Double oops.

Reload again, because of course I'm going to reload it when I forgot to put the pilot back in the lander. Third time's the charm-

RD-58 failed on ignition.

With a 0.7% failure rate. It already worked perfectly fine twice for a total of seven ignitions. Go away, TestFlight.

F9

First try! 

1967-06-08, still two years before Apollo 11 and the second lunar landing is complete. By nothing more than sheer happenstance, I even landed the lander in the right biome for the targeted Moon landing contract. Should've looked at the contracts at some point during this mission.

With the surface stay complete, Robin heads back to orbit. No failures of any kind happened, probably because I used up all the failures trying to land.

Direct rendezvous during the ascent saved time, but left little fuel in the tanks by the time Robin docked up again. A single ignition remains on the RD-58 engine, but it won't be needed.

Once crew and science data have been removed from the lander and any usable resources transferred across, the lander was undocked and deorbited to avoid space litter. It feels like a waste, throwing these landers away each time, but at some point I'll put together a reusable version- maybe using one of the AJ-10 engines with the ridiculous rated burn time and infinite ignitions, or with generic thrusters all round.

Mission accomplished, the contracts pay out some big bucks.

More science gathered from the (newly unlocked, apparently) deep surface sample crew experiment and that blood thing again, plus a big retirement delay for Robin and a decent one for Patrick too.

Spoiler

Full album: https://imgur.com/a/StTqVbo

Coming soon: The belated launch of Blue Sitar 1 to chase the Venus transfer window and the first Mars-bound missions arrive.

[jimmymcgoochie]

A contract completed on the Moon as Green Huckleberry 4 arrives at the rover waypoints and does a few drifts to celebrate.

Between that money and the advances from several large contracts- including lunar base and space station- there was enough to pay for the final R&D upgrade plus change.

The Green Kiwi rovers arrived at Mars, spread a couple of days apart, but...

Landing on Mars without a heatshield from low Mars orbit is possible; landing on Mars without a heatshield on a hyperbolic trajectory is emphatically not. RIP Green Kiwi 1 and 2.

But weirdly, this contract completed:

I'd say the generic contract blurb is actually pretty accurate in this case- I learnt much about the atmosphere of Mars, specifically "don't just yeet probes at it on an interplanetary flyby trajectory without a heatshield".

From Mars to Venus: Blue Sitar 1 launches, somewhat late, to head to Venus.

A good encounter that will set up a polar orbit, ideal for scanning and for deploying the four landers.

Still with the interplanetary missions, Green Banana Saturn launches for a flyby of the ringed planet. The heaviest Green Banana to date (and probably ever, since it's almost 350 tons on the pad), it'll need all the fuel it can get to fly past Saturn and maybe, just maybe, make it into orbit.

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There are still some occasional issues being caused by the combination of negligible impact tolerances on engines and slightly odd collision meshes on the RD-107/108 engines; decoupling the solid boosters did this:

Perhaps unsurprisingly this launch suffered a loss of control and RUD shortly thereafter, but decoupling the solids a bit later the second time around avoided the issue.

Despite dipping to 120km altitude during the transfer burn (probably should have remembered that from the sim and launched higher) the probe was sent off to Saturn without any trouble, even setting up a blink-and-you'll-miss-it flyby of Enceladus on the way past.

Whatever fuel remains in the upper stage and the probe's own tanks will be used to try to capture into orbit at Saturn, potentially allowing more moons to be visited to bag even more contract money.

And finally, the first flight of the Green Cucumber GEO to geostationary orbit went flawlessly, bagging the first of many geostationary satellite contracts and proving itself ready for mass-production.

Spoiler

Full album: https://imgur.com/a/VmAniUb

Coming soon: Prototyping a 1500 ton rocket, and getting caught out by my own hubris...

[jimmymcgoochie]

Let's launch a "power module" for the Yellow Timpani space station! Except that it doesn't actually need any more power generation since the solar panels are more than enough as it is, so instead the "power module" will be a propulsion and avionics module instead.

Ta-da, launch successful. Now all that's left is to wait a few days for the orbital rendezvous and-

 

 

Oh.

 

The "power module" can't even power itself. That single small solar panel on the bottom isn't enough to run the avionics even in daylight.

Serves me right for trying to cheese the contract. 

Meanwhile, that 1500 ton launchpad will need a 1500 ton launch rocket to go with it. My first idea was to just add some boosters to the Blue String, but that proved to be impractical due to excessive engine overburning, so I decided to just staple the "boosters" directly to the core to create a 13-engined Proton-esque first stage.

The second stage is almost unchanged from the Blue String, except that it now uses two RL-200s instead of one to compensate for the heavier payload mass; a feature I may or may not keep since it manages well enough with one engine right now.

Total payload to orbit is 75 tons, with a small delta-V reserve left over.

So far, so good, but now comes the expensive bit: tooling. This seems like as good a time as any to upgrade to aluminium-copper fuel tanks which have a better mass ratio than ordinary aluminium, which will also allow the Blue String to be upgraded if I want to. There's also a new 1500 ton avionics unit and the unlock costs for the next level of avionics that come with that.

Almost 150k funds to tool two new fuel tanks and one new avionics, ouch.

However, it slashes the build time by more than half and the build cost by more than two thirds. Two launches and the tooling will have paid for itself versus not doing it.

I also took a swing at making a crewed lunar rover that could be bolted to a lander for a contract, with some success.

The ability to fly probably won't be needed and the fuel tanks could be made much smaller as a result, but the design shows some promise. Even if the poor Kerbal in the sim suffocated to death because she spawned in with no life support resources in that chair.

Spoiler

Full album: https://imgur.com/a/NLxTfz9

Coming soon: Launching another "power module", this time actually able to generate enough power to keep itself running.