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

[jimmymcgoochie]

Yes, thank you KSP forum, I know this thread is quite old- three months?!

With RP-2 now released and several minor versions in (2.4.1 at time of writing), this old install is starting to show its age. Time to wrap things up in a suitable manner- with a crewed Mars landing! Well, the planning stages of it for now, but the landing itself will come soon(ish).

So I dug out the old Mars lander I used before (still blatantly stolen from Terminal Velocity with minor tweaks) to see if it still worked.

And the answer is...

Yes, if flown correctly. It also gets back to orbit after landing with enough fuel left to do a rendezvous and docking.

For the Mars ship itself I'm trying something different: nuclear propulsion. It'll make for some very long burn times and boiloff troubles, but it also means I can make the entire ship, with four drop tanks, weigh less than 700 tons including the lander; my last Mars ship was over 2000 tons fully assembled and required some ridiculously large rockets to get it there, but this one should be possible with merely huge rockets.

I'm not sure if the fairing is longer than the whole rocket. It's needed to cover up the entire core section of the ship- nuclear engines, main fuel tank, crew habitat and the life support and consumables storage section- which can be launched in one go, but only with a half load of hydrogen in the tanks.

The side tanks are much lighter and can be launched on a smaller rocket. I was surprised just how much I could cut out of the Violet Element design- first the second stage, then a booster, then all the boosters- and still make it to orbit with this payload. Only the first and third stages are left, cutting the gross launch weight by more than half.

Each tank has a small propulsion stage on it to perform the rendezvous with the ship, but I'll need a separate assembly drone of some kind to dock everything together as the tanks have no control of their own.

With the plan for Mars firmed up, it's back to the real launches as a Yellow Gong G sends up a crew to the Yellow Timpani station, bagging a couple of contracts.

The supplies are more than adequate to attempt a 90 day stay to get a duration record.

On to the next launch, the Green Emerald lunar communications network. The design borrows heavily from the Green Basalt lunar rovers including the odd conical upper stage.

As is often the case in RP-1, several things were happening at once: while this mission travelled to the Moon there was a course correction for the asteroid chaser mission to set up its intercept, then over to Venus as the first of two rovers arrived.

Everything looked good, until everything exploded because I was a cheapskate and skimped on ablator. RIP rover, and probably the second one arriving a week later.

Back to the Moon for the resonant orbit shenanigans:

They'll circularise one at a time into an evenly spaced orbit and their dishes have already been set up to point at each other to ensure a signal almost anywhere on the Moon's surface.

Final scores, with a big glut of free KCT points arriving all at once:

Spoiler

Full album: https://imgur.com/a/p1oq11U

Next time: Five drop tanks for the Mars ship are on the build queue, but they'll need refitting once the radiators get researched. The ship is also waiting on research as the node with radiators is a prerequisite for the nuclear engines node too. In the meantime, there's a Moon station to launch and possibly send crew to.

 

[jimmymcgoochie]

So it turns out the next Mars transfer window is over 600 days away, meaning plenty of time for some filler- er, other missions. Money isn't an issue after accepting the crewed Mars missions (and crewed Phobos landing) and I only need two more research nodes before the Mars ship can be fully built ready for launch.

Picking up where the last post left off, the Green Emerald lunar relays performed their burns and synchronised their orbits to within 0.001s, providing high-bandwidth coverage with the existing network of three relays in a different plane acting as a backup to make sure there are no blind spots.

Staying in Earth's SOI, if only just, the asteroid chaser mission arrived at its destination and, eventually after some weirdness with the klaw, grabbed onto it to complete the contract.

RSS asteroids are still stupidly big...

Contract complete, now this multi-gigaton mini-moon has two tiny probes stuck to the surface! This is probably not what the contracts had in mind, but if an asteroid happens to get captured into Earth orbit then I'm not about to pass up the opportunity for easy money.

Back on Earth, Green Basalt 3 rolled out to the pad to launch to the Moon, but things didn't go to plan:

This was the first of several NK-33 failures today and forced a rollback, engine replacement and rollout before the second launch went ahead without any further issues.

It'll stay here in Mare Serenitatis for three months before moving towards Mare Frigoris.

A quick check in on the second Venus rover revealed an even bleaker situation than its sister craft: phantom boiloff had evaporated all the lox and the craft was on a collision course with Venus. Not even the news that the Mercury biome scan was complete could lift the mood in Mission Control as the second rover plunged to a fiery doom, and with it any chance of fulfilling that Venus rover contract since the deadline is in less than a year.

Unlike the rovers, the larger orbiter mission arrived without incident and parked itself in a polar orbit for optimal mapping and science gathering.

More rover-related action as the two Mars-bound rovers perform small course corrections...

And then it's on to the big ticket event: Yellow Vibraphone, a modular lunar space station and future hub for lunar activities, or at least for one landing at that Moon base I still haven't visited for the contract yet.

The core module was first to launch on a four kiloton Violet Element rocket; one of the few gimballing engines failed on the core, but this didn't cause any issues and the launch went smoothly.

After capturing into orbit, the hydrolox upper stage was retained to aid future mobility in case one of the other modules had trouble rendezvousing. The core contains avionics, power generation, propellant storage for the reusable landers, hydrolox for fuel cells and life support consumables along with eight reaction wheels, which between them are more than enough to handle attitude control for the core (and indeed the entire assembled station) without the need for RCS.

Next to launch were the propulsion and habitation modules, sharing a ride to the Moon as their combined weight was slightly less than the core module. An engine failed on the pad, but faced with a month-plus turnaround time to roll it back and replace it I decided to just launch and the rest of the engines worked properly.

At first I thought I'd botched the design, but past me clearly knew better as neither module has their own avionics and there are small solar panels on the bottom of the upper stage to keep the batteries on its avionics topped up for the journey over to the Moon.

Docking was pretty easy thanks to the substantial propellant reserves and powerful RCS, but the modules would need to be moved to their correct positions.

The upper stage connected to the core was drained and decoupled before the core and hab modules disconnected from the propulsion module, pivoted 180 degrees and re-docked so the core was attached directly to the propulsion module. This does mean that the hab is technically upside down, but it's not something that can be fixed easily as the only avionics are on the station core and it doesn't really matter anyway.

The last of the three launches is the lab module, using a lightweight version of the rocket that I'm calling Violet Particle- no boosters, no second stage, half the weight of the original.

Unfortunately past me dropped the ball with this one- using a J-2S on the upper stage meant that it didn't have the engine ignitions to do the rendezvous. The lab's own RCS systems did most of the intercept burn, while the station itself had to perform the velocity matching burn and then dock.

The station is now complete and ready for its first visitors. All that remains is to send a crew, a reusable lander and a supply tanker to prove that it's fully functional.

None of which I've actually built yet, or even settled on the final designs for...

Spoiler

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

Next time: Lunar station and base stuff.

[jimmymcgoochie]

A lot of SCAN contracts completed during this update but I won't post those here as they're not really that interesting.

Lunar stations old and new were joined together, adding some useful extra supplies and a bit more room for the crew which should be good for stress.

The crew rover on the Moon wasn't doing nearly so well- first the Kraken attacked, smashing solar panels until I had to ditch the skycrane, then it kept spawning in standing on its face instead of its wheels and on at least one occasion it clipped into terrain and exploded everywhere.

Heading further afield, a Vesta-bound probe arrived and performed its capture burn.

Orbital velocity is less than the stock Mun and gravity is considerably less, so that 3500m/s fuel reserve is ridiculous overkill and this mission will be able to perform several landings to cover all the biomes if I decide to do so.

Back to the Moon with a test launch of the Purple Parallel lunar tanker. 

Five planets in one screenshot!

The mission wasn't without its problems- the avionics is too small and needs to be bumped from 50 to 60 tons to handle the full weight, but by dumping some unneeded resources the weight came down to a manageable level.

Then it was time for the first landing using the reusable Moon lander, attempting a targeted landing near the waiting lunar base. It went-

-not so well. Slow acceleration combined with some frantic terrain avoiding action pushed the landing site nearly 70km from the base, but that's what the (mildly cursed) rover is for!

Moon newbies Elizaveta and Achim posed for the obligatory flag planting before settling in to wait for their ride.

Spoiler

PSA: when using BonVoyage to drive rovers towards other vessels, always change the target coordinates slightly (add or subtract one from the first decimal place and delete the rest) to avoid the two vessels clipping into each other and exploding.

Unfortunately the lunar base contract is broken and seems to think that the Yellow Vibraphone lunar station is actually the base. I still waited the full 30 days as required before sending the crew back to their lander, but by then their landing site was out of sync with the orbiting station- so there was plenty of time for a road trip!

This install is getting really cantankerous- I was getting anywhere from 1-3 seconds per frame in the Tracking Station while the rover drove around on autopilot at 1000x time warp, Parallax keeps glitching with holes in the surface through to the void beneath (visual only) and Kerbalism broke when I tried to turn on a fuel cell on a vessel and then refused to work for any other vessels until the game eventually crashed. Regular quicksaving is important!

On the plus side, that lander now has five deep surface samples from various biomes in it and space for even more, orbits and daylight dependent (Bon Voyage probably won't work at night as it's a bit picky with Kerbalism power sources and there's not enough hydrolox for the fuel cells for a full lunar night) before they head back to the station to either process the samples in the lab or pack them into their D-2 capsule for the trip back to Earth.

Spoiler

Full album: https://imgur.com/a/v4jcYbg

Even Imgur is glitching with this save, deciding to turn my nicely organised album into a mess of individual images with no captions and forcing me to do it all again.

Next time: Mars ship launches?

[jimmymcgoochie]

With the lunar night fast approaching, Achim and Elizaveta returned from their roving and waited by the lander for the launch window, then flew back up to the Yellow Vibraphone station where Liz could get to work crunching through those samples in the lab. No point dragging ~200kg of samples back in the capsule if they can be processed in lunar orbit instead.

Meanwhile, over at Vesta, Blue Mandolin Vesta 1 touched down on the surface...

...Blue Mandolin Vesta 2 shifted into a polar orbit to maximise its orbital science returns...

...and the old flyby probe Green Banana Vesta flew past for the second time!

Spoiler

This second encounter was set up during the first one, way back in May 2022.

I could have fiddled with a node to get a third flyby but I'm not sure I'll keep this save going after the Mars crew returns and besides, what's the point? All the science has already been done by the orbiters with their superior experiments. I decided not to do a course correction to get a second flyby on a Mercury probe for the same reason- a better orbiter has already arrived and done the science, and sadly Cool Points are not an RP-1 currency.

Over to Mars for the arrival of two rovers (OK, I admit the second one required some cheating since it somehow managed to miss its encounter with Mars by a billion and a half kilometres despite a sub-200km periapsis after the course correction).

The first landing was fine, rover touched down safely and in one piece, then I decoupled the skycrane and-

Boom, no more rover. The little red speck in the bottom centre of that image is a secondary science core equipped with some experiments, a battery and a transmitter; it was supposed to be the control point for driving around on the surface, but instead it gathered some data and transmitted as much as it could before the battery was depleted, completing a contract in the process.

Yay?

The identical second rover arrived shortly afterwards, had an equally perfect descent and landing with no issues.

So I quicksaved, then lifted it a couple of metres off the ground with the skycrane before decoupling- and it immediately yeeted the rover into the ground at close to 40m/s, smashing it to pieces just like the first one. Between that, the mysterious trajectory error and a litany of other bugs including Kerbalism's UI breaking when I try to toggle fuel cells, chronic frame rate issues going above 1000x warp and repeated instances of Kerbalism blocking timewarp above 1000x on the launchpad for no reason, I'm glad this career is nearing its end.

Speaking of which...

The Mars Ship core launch suffered one booster engine failure on the pad, but went ahead without any issues regardless. It arrived in orbit with some fuel left in its upper stage, quickly transferred into its main tanks. A bit of research queue tweaking ensured that it launched with the latest TL4 solar panels- now with sun tracking!- and the launch put it into the right orbit for its eventual departure, about a year away still.

The second launch was the much smaller Green Feldspar orbital assembly tug.

It might not be very fast, but it has plenty of fuel and oversized RCS plus a reaction wheel to haul those hundred-ton side tanks around and dock them to the ship.

But first it "docked" itself to the ship to await the arrival of the first tank.

The first tank launch was stressful- the little upper stage I added didn't have nearly enough RCS propellant so the tug had to chase after it, grab it and then try to manhandle it back to the ship despite having some serious imbalanced thrust issues that made it really hard to make it go in the right direction. Much keyboard mashing and a few awkward minutes of rubbing the docking ports together because they wouldn't connect...

After that painful experience, I went and modified the other four tanks- the solar panel has moved to the top of the tank to make room for a second docking port so the tug can line itself up properly for balanced thrust and much easier dockings. This tank was used to fill up the ship's own hydrogen tanks and the excess added to the rocket stage before being undocked and thrown at the atmosphere by the tug which was then able to do a U-turn and come back without even leaving physics range.

Rather annoying contract failure considering the probe to complete it is already flying past Jupiter, just not reaching its periapsis soon enough:

And then it's on to the launch of the second fuel tank.

Which was scrubbed after three simultaneous engine failures on the pad, with a fourth occurring when I accidentally double-clicked the button on MechJeb and restarted PVG briefly, causing it to reignite the engines. The previous launch had one failure out of 31, but this is 4 out of 19 on a supposedly reliable engine with a >98% ignition chance and full data units.

While that rocket rolled back to have its engines fixed, another was ready at the other unlimited mass launchpad.

No failures this time!

A relatively quick encounter with the ship is on the cards, but that'll have to wait until the next report.

Spoiler

Full album: https://imgur.com/a/7Tb5W3q

Next time: Orbital assembly continued.

[jimmymcgoochie]

Continuing where the last report left off, another Mars ship drop tank made its way to the ship and docked. Unlike the first one, this one and the other three to follow will be remaining docked for the Mars transfer and possibly capture burns.

By this point I deeply regret the decision not to put avionics and RCS on the drop tanks themselves as trying to drag them around with the Space Tug is a real pain, especially for lateral movements (strafing left/right and up/down) since the thrusters almost cancel each other out leading to very sluggish handling and a lot of wasted propellant.

With the engines now fixed, tank number three (formerly two) was lifted to join the party.

One engine failed on the launch of the third "permanent" tank, but no need to halt the launch because of that.

If you think this report is repetitive, I had to fly these missions with terrible frame rates at the ship itself and very cantankerous controls even with the help of the second docking port per tank to line the Space Tug up perfectly.

To break up the monotony I went to check on the lunar station as there was a low water alert and I wanted to see if the samples had been processed yet. The water situation was resolved by retracting the solar panels, while there are 1 and a bit samples left to process and a couple of months left on the crewed lunar orbit contract that'll be done after they leave the station. They also set an endurance record of 180 days in space, a feat that the Mars mission will easily surpass.

The final tank launch:

The tank was docked but I forgot to screenshot it as I was distracted by a problem- one of the ship's core tanks was completely empty! A smaller top-up mission was prepared to fix that issue and also fill up the Space Tug's badly depleted propellant reserves, and the ship's, which had been heavily used up trying to help out with the last docking so the Space Tug didn't run out.

Meanwhile, Green Banana Jupiter finally reached its periapsis and completed that flyby contract that timed out a few weeks earlier.

The shadow belongs to Io, not the probe.

A successful capture burn later and it's in orbit with fumes left in the tanks. Science is already flooding in as fast as the two little RTGs can top up the batteries, not that I actually need science any more because I just added the final node to the research queue.

The Purple Chord emergency tanker lifted off with a big tank of hydrogen and some extra RCS propellants. An amalgamation of pre-tooled parts, it won't win any beauty contests but it'll do the job just fine.

It's powered by a pair of nice reliable RD-58S-es which have a really high ignition chance-

-so naturally this one failed on the first ignition. Fortunately the other engine could just gimbal enough to keep it flying straight and it flew in a permanent powerslide to meet up with the Mars ship.

Again I forgot to screenshot the docking itself but the ship is now fully topped up and ready to go as soon as the lander and crew arrive. The lander might be a problem though- I tried launching it but it didn't even make it to orbit, spun out of control and then the game crashed.

Spoiler

Full album: https://imgur.com/a/Oz5qHJf

Next time: Launching the lander.

[jimmymcgoochie]

With the Mars window rapidly approaching it's time to get rid of any other distractions. Nothing drastic, just bringing the crew home from their extended stay in the lunar station. For now...

What started out as an unplanned and unwanted skip back out of the atmosphere became a fully guided lifting re-entry with the target refined from "somewhere near Florida" to "somewhere near the KSC" to "launchpad" to "VAB roof?" before running out of time and ending up half way between the launchpad and the VAB roof. It may have been completely unintended, but this is my most accurate re-entry ever in RP-1 and I couldn't replicate it if I tried.

Why haven't I been using Trajectories until now!?

I forgot that the lunar base contract was incorrectly pointing at the Yellow Vibraphone station so it didn't complete when it should have, I'll get to that later.

Only one piece of the Mars puzzle remains- the lander. I'm reusing the same design that worked in Terranism Space Program, which in turn is a near replica of the design in Terminal Velocity. It worked just fine before, it worked just fine in the simulations, so it should work just fine now, right?

Spoiler

Spoiler alert: IT DID NOT WORK JUST FINE.

A late change was made from using a Blue String class rocket to a larger Purple Geometry so that the lander would a) make it to orbit and b) make it to the ship without using any of its own propellants, which was accomplished by adding an upper stage.

Said upper stage still has plenty of fuel in it so I can use it to deorbit the lander over Mars.

And finally, the crew. Original Moon landers Klaus and Vera are going as pilot and scientist respectively, with Patricia filling the role of engineer in case that's ever necessary. They headed to orbit on a Yellow Tambourine, a basic capsule-only D-2 designed for simple station taxi work.

The design hasn't flown before and it turned out to have a couple of flaws...

That wasn't meant to happen! Turns out that decoupler with the RCS on it was attached to the top of the docking port which would prevent the port from being used. The problem has been corrected, but the mission proceeded with the capsule's RCS system active for docking.

The crew settle in to their new home for the next few years while the capsule heads back to the surface. Another problem reared its head as the service/propulsion module didn't separate properly until the capsule was well inside the atmosphere, but it still made it to the ground in one piece.

38 days later it was time to go.

The departure was split into three burns to break up the extremely long burn time- TWR is 0.09- and then they were off, the first Kerbals to leave Earth's gravity well and head for another planet.

One set of drop tanks didn't make it beyond Earth's SOI, but the Green Feldspar space tug is coming along for the ride in case it comes in useful later.

Spoiler

Spoiler alert: IT CAME IN VERY USEFUL INDEED!

Meanwhile, over at Jupiter, a flotilla of probes are gradually arriving- one Green Banana, two Blue Mandolins and two Purple Cubes, launched years apart, are all turning up in close proximity to each other.

Blue Mandolin Jupiter 1 set about doing All The Galilean Moon Flybys with close passes with Callisto, Ganymede and Io in rapid succession and a flyby of Europa planned in a few orbits' time.

The Jupiter stuff will be secondary to the Mars mission if they ever clash, but that's unlikely.

Spoiler

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

Next time: The Mars mission arrives.

[jimmymcgoochie]

Before getting into the Mars stuff, here's the Europa flyby to complete the set.

Oh, and the Jupiter orbiter contract too.

A mid-course correction for the Mars ship, carried out using the lander's upper stage because there's no point using one of the limited number of ignitions on the nuclear engines for 5m/s.

More contract stuff also happened in the background- lunar base completed (forcibly, but the contract was convinced that the lunar station was the base in question) but the Mars rover contract timed out mere days before the one surviving rover managed to drive half way across Mars to reach the target site (I should have started it off sooner).

And now on to the crewed Mars mission as it arrives at its destination, with a coincidental flyby of Phobos.

The final orbit was about 1000x6500km, the apoapsis crossing Phobos' orbit to make getting there later more straightforward. The lander still has a good chunk of fuel in its upper stage to deorbit and slow down so it's no big deal.

And that's when everything went wrong...

The lander didn't work. AT ALL.

Somewhere along the way it picked up some kind of phantom force or some parts got bent slightly out of shape because it was completely unable to point in the right direction during re-entry. All the simulations beforehand said that it was a bit finicky but would still hold retrograde the whole way down, but for some reason it just kept flipping "nose-up" to point prograde- even with a 4kN thruster pushing it "nose-down" along with the RCS!

I did some more sims after that, dropping the lander and its upper stage into the same orbit as the Mars ship and flying the same re-entry profile, and it worked exactly as it had in every other sim- stable retrograde all the way down.

Spoiler

Here's one of those sims. The "real" lander would have flipped and its fuel tanks burnt up by this point.

So I cheated the lander stationary above the ground mid-descent and flew it the rest of the way to the surface.  It took a lot of time and effort to build the ship in orbit and send it all the way out here and I'm not about to have the entire thing fail because of some KSP weirdness.

The crew headed out, did some science, planted a flag for posterity (and a few more for fun) and wondered why the ground looked heavily pixelated.

Like I said, KSP weirdness. This save and install date back to February last year and there have been many mod updates and changes in that time which probably haven't helped.

A quick look over to Jupiter as another probe arrives. I poked around with TUFX profiles but while some look pretty good (see below) they often cause a lot of blurring in time warp so I don't usually use them.

The Mars landing contract wants a 30 day stay on the surface, so the crew stayed for 30 days and nearly ran out of water several times, using up some of their rocket fuel to make up the shortfall via the fuel cells. This combined with boiloff meant that they struggled to make it back to orbit, ending up stuck in a low orbit at about 200km with no way to rendezvous with the ship. 

If only I had a small detachable vessel with loads of fuel and a grappling Klaw that I could send down from the ship to rescue the lander...

See, I knew keeping that thing around was a good idea!

Even so, getting to the lander and then towing it back used up nearly all the propellant on both the tug and the lander. What's left of the RCS propellants will need to be carefully rationed to make sure they don't run out.

Well, that's the Mars landing done* (I landed the un-broken lander in the sims so that counts!), now all that's left is a quick trip to Phobos and then a return to Earth, preferably before the crew go mad from stress or die of radiation poisoning since using fuel tanks as shielding is once again not working with procedural parts.

Spoiler

Full album: https://imgur.com/a/JKc2Nw0

Next time: Phobos, then home to finish the series.

[jimmymcgoochie]

Time to finish this report off with a nice visit to Phobos.

Meanwhile, in a kill-two-birds-with-one-stone move, the Blue Guitar Deimos probe that has been sitting around Mars' other "moon" for some time now did a quick landing, grabbed a surface sample and then flew down to Phobos to rendezvous with the Mars ship.

Spoiler

Glossing over the fact that Phobos went AWOL during this exercise, flying off in completely the wrong direction and wasting a lot of fuel trying to get there. Good thing the probe had a lot of fuel in reserve!

Is it any wonder I'm done with this save?

Klaus then headed out to grab that precious slice of Deimos and stow it safely onboard the ship.

Contract completed and sample secured, a successful end to a successful mission.

Next up was the Phobos landing, in a very generous use of the word "landing" since it was done entirely using RCS.

The crew had a bit of time to faff around- er, gather surface samples and conduct other valuable science experiments regarding the extremely low gravity environment. Why else would they all plant flags?

The stay on Phobos was relatively short and soon enough they returned to the mothership.

A quick bit of resource shuffling later and the lander, now drained of anything useful and those precious samples, is cut loose in Phobos orbit. I tried to ditch the tug as well, but despite releasing and retracting the klaw it just wouldn't let go.

The options are a) wait over a year for a proper transfer window and have the crew die of radiation poisoning before getting home, or b) burn nearly all the remaining fuel to leave RIGHT NOW and take a less efficient route that'll arrive sooner.

Things kept getting even weirder- first the Mercury rover developed the ability to levitate:

Then whatever this is, happened:

And then at long last the journey home was almost over. Time to move those samples over to the return capsule, fill all the tanks as much as possible and then separate for the deceleration burn before re-entry.

Re-entry was surprisingly benign considering the high-energy transfer, and also flew past Florida on the way down before landing in the Atlantic Ocean somewhere east of Bermuda.

Spoiler

Contract montage!

(This one is slightly cheating since it was supposed to be uncrewed, but at this point I'm past caring.)

 

And the final final scores for this report:

I might come back at some point and just time warp through all the active missions until they arrive- Neptune's still many years away- and see how long it takes to research everything, but not now.

Spoiler

Full album: https://imgur.com/a/PBOh09V

What next? In the short term, it's back to EuroStar to see if I can beat Apollo 11 to the Moon; I have some ideas for an all-American P&LC run (don't expect any detailed replicas of IRL rockets though) but I'd rather focus on one thing at a time instead of trying to keep track of two or three different saves and their respective copies of KSP with different mods in each.