Ultimate Steve

Not that surprising, iirc the FTS is mainly intended to unzip the tanks to disperse the propellants, stop the vehicle from producing thrust, and create a small boom in the air instead of a big one on the ground. The front would likely survive this and I don't think it necessarily has to be a problem.

SECO!

5 minutes. See yall on the other side of this! Although it may take longer, apparently they are still working a few boats. Might hold at T-40.

Confirmation that hot staging is all 6 engines, not what I expected. Spicy!

Another thought, subcooling the propellants (I forget if starship does this or not) could provide a buffer against boiloff. Propellant seems to have an average of about 2kJ/kg K of heat capacity. At 100 tons per mission, that's 200MJ of free ish cooling per Kelvin. If everything is subcooled by 5K, that's a gigajoule. At the 36300ish watts of heating I calculated above, that is about seven to eight hours of boiloff buffer. Not much given that we were talking about days between flights, but enough to be significant.

Envelope math time. Let's go worst case scenario here. Starship radiates no heat, reflects no heat, and has 500 square meters of area exposed to the sun. 1380W/m2 hits Starship from the sun, for a total of 690000W. The latent heat of vaporization of oxygen is 214,000J/kg, and Methane is 510,000J/kg. Oxidizer to fuel ratio is roughly 3.5, so average latent heat of vaporization is ~280,000J/kg. In this scenario where zero mitigation is taken and all of the heat hitting Starship goes towards boiling off the propellants, Starship loses about 2.5 kilograms per second. It will spend ~60% of its time in sunlight (probably a bit high, but again, worst case scenario), so a whole 129.6 tons of propellant is lost from Starship per day. Starship would have to launch nearly one refueling flight per day just to keep up with the losses, in the optimistic 150 tons to orbit reusable config (about the higher end of what has been estimated for reusable mode). This is obviously not a realistic scenario, but it highlights how conservative assumptions can lead to large estimates. Stainless steel has something like an albedo of 0.6 (60 percent reflected, 40 percent absorbed), and with the nose facing the sun at all times, the exposed surface area is about 64 square meters. This decreases the incoming power to around 36000W. Starship will also naturally radiate some heat away. LOX is about 54K, CH4 is around 90K, some of the ship isn't up against cryogens at all, but I will assume the ship's skin is at an average of 60K, conservatively low. Stainless steel's emissivity, I'm finding a large range, let's go for something conservatively low at 0.55 (values up to 0.85 are reported). Starship's surface area is about 1500m^2, it should be higher probably, but again, conservatively low. Plugging those into the Stefan-Boltzmann equation gives a radiative flux of, uh, about 600W. Not great. Radiative flux scales with temperature to the fourth power, but we still won't get nearly enough flux even raising the entire skin temperature to 110K, the upper end of methane boiling temperatures. One thing that could be done is to have a double hull for the nose cone, which is pointing towards the sun here, which is moderately well insulated from the rest of the tanks. This could even be done by just having the nose cone empty as with a normal non depot starship. The interior would be coated to reduce interior radiation transfer. This would allow the, worst case scenario, 64 square meter circle to get much hotter than the rest of the ship and radiate more effectively. The nose is conical, but I'm not sure how to do the math on that, so I'm going to take the volume of an equivalent sphere (should be roughly equal to that of a half sphere stretched by a factor of 2, but not exact). This gives a surface area of about 250 square meters. To offset the rest of the flux from solar heating, the nose would have to rise to about 260-270K. Conduction to the rear of the ship over the surface area of the very thin tank walls (let's be extremely generous and assume 5 centimeters thick taking into account internal radiation bypassing the nose shield and stringers and such) (surface area ~1.4 square meters) (90K CH4 tank immediately behind 270K nose cone) will be calculated also. The section between the tank and the nose is, what, 10 meters long on an unmodified non depot starship? The depot one may be different but the extra length helps us here. Heat getting to the fuel is now 369W, and as we found earlier, Starship radiates about 600W by itself. Even assuming it doesn't, we have reduced the boiloff, in theory, to 114kg/day. Even if I'm off by a factor of 10, just by pointing Starship in the right direction, with not that much modification, that's like a ton of fuel per day, which is well manageable. Unfortunately, it isn't that simple because the Earth is reflecting and radiating heat as well. This ends up totaling roughly 345W/m2 averaged over night and day at the surface, as the Earth is (mostly) in equilibrium, and has four times as much surface area as it does cross sectional area. If Starship is 400km up, this decreases slightly to about 305W/m2, although the atmosphere is further out than the surface so it will be a bit higher than that. Now we get into the wonderful world of materials having different reflectivities and emissivities for different wavelengths, and I'm going to handwave this and say everything is the same as it is coming from the sun. Starship is pointing at the sun, so can't really control its Earthwise orientation. Averaged over the orbit, I'm going to assume an average Earth facing cross sectional area of 300 square meters (450 is the max, 64 is the minimum, approximately at least, this whole post is filled with approximations). With the same albedo of 0.6, Starship will receive an average of 36,600W from the Earth. Due to our solar mitigations, assuming they actually work, the Earth radiation now dominates and is much more difficult to protect against. It is possible the heat shield has better radiative characteristics and could be oriented towards Earth for maximum effect, but the depot probably won't have a heat shield... It could have some other thermal protection in its place, though. This is beyond the scope of my analysis. Total power reaching the fuel is roughly 36,600-600+370 = 36,370W. This is about 0.13kg/s, or 11.2 tons per day. Not great. If we conservatively estimate 100 tons of propellant per trip, and a full load of 1300 tons required, that is 13 trips for the principal, and then 1 more trip for every 9 days it takes. If we assume two ships per week, or one ship every two weeks from each of the four pads, that is a total of 22 refueling launches over the course of 77 days if I did the math right. Keep in mind that this is all an extremely rough approximation, but it shows how upper teens could be a realistic number. High ones could also be realistic if the assumptions on capacity, flight rate, load needed, and thermal protection were changed. We simply don't know enough. If my calculations are correct, and Earth heating is the driving force, deep space boiloff should be incredibly minor. Unfortunately this means pointing the crew compartment at the sun, which is explicitly what they talk about not doing for Mars.

It's finale time! Now in 0.1.5, I plotted a return trajectory. It was not very efficient, but I got a trajectory, and working without KSP 1's precise node editor was making me angry, so I stuck with the awful transfer I came up with. This maneuver of course used most of my fuel, meaning there's little left to circularize at Kerbin, but as long as I make it back before 0.2 drops, aerobraking will be a viable option. Goodbye, Jool! Several years and corrections later, the Kerbin aerocapture pass is set up. The ISS Infinity was captured into an elliptical Kerbin orbit, and WOW is that picture gorgeous. On the next aerobraking pass I went way too low, and got to see for the first time how the music gets really intense when you are about to crash. A quick quickload later, and we successfully aerobrake after a few attempts, and enter a roughly 220km Kerbin orbit. I threw together a quick mission to bring all of the crew back to Kerbin. Docking was a bit annoying. I feel like RCS is weaker in KSP 2 than in KSP 1, but it might just be my sense of scale failing me. This is a 3.75m ship using just normal sized RCS, after all. The ISS Infinity is looking kind of small from here actually. It seemed so huge and mighty but next to a proper return vehicle, the scale just kinda feels goofy. A screenshot of the crew for posterity. The new Kerbal expressions will make it much easier to tell Kerbals apart in screenshots, and gives them a little personality. It will be much easier to keep track of and get attached to them, which will hopefully have huge benefits on user generated lore. Having lots of fuel left, the return spacecraft executes an attempt at a precision landing, burning most of the remaining fuel. Deep inside the atmosphere, the service module is jettisoned. The landing site was undershot a little, but the parachutes deployed just fine! The crew reporting in, glad to be almost home! And ladies and gentlemen and everyone else, Bob Kerman is back on Kerbin! Taking a big stretch and planting a flag for the occasion. My second major KSP 2 interplanetary mission has been completed! (first one was an ill fated Duna mission, I think the lander was too draggy to make it back to orbit) Thank you for reading!

Now the question is, do I bother sleeping...

Hey, I have a launch in my time zone so I don't have to do conversion for once, let me have this one!

This reminds me a lot of the older days of the forum. I am very much looking forward to seeing more of this!

Hopefully finishing up the old 0.1.3/maybe 0.1.4 stuff with part 3! The more I think about it, the more I think this was all in 0.1.3 though. This phase of the mission, if I remember right, was having severe issues with, well, not orbital decay, but probably the same bug. My orbit kept on rising from a low circular orbit to an elliptical orbit that impacted Laythe. I took this opportunity to get a launch assist for the Jool probe, and returned the mothership to a stable orbit. Part of me wishes I had waited to do this until after 0.1.5, because of Blackrack's new cloud revamps, but that just means I get to do a before/after comparison if I ever do this again. Although tbh, this is already miles better than KSP 1. Entry was a bit anticlimactic due to the current lack of re entry effects and heating. I wonder how forgiving the new system will be. There's a fine balance here, too forgiving vs too intense, I wonder what we will end up getting. Even at nose down, it still took a long time, as it did in KSP 1. Sun so small out here. Descending below the cloud layers. Interestingly, the sun does not seem to be affected by the clouds. A weird repeating pattern happens when the clouds are too dense, which kinda looks like a sandstorm filter on old films. Deep inside the clouds, what is that... Is that a surface? Indeed! And the atmosphere is so thick, we can just land with no landing gear fully intact. This isn't news to anyone who has been paying attention, but I managed to get this far without knowing. Granted, this was five months ago, we were still new to the game. I kind of hope it stays this way. Not realistic, but it means that Jool bases and Jool ascent vehicles can be a thing that happen now. Jool might become the new Eve in terms of challenge. I remember back in KSP 1, everything seemed a lot harder in the old days. We had less tools to work with and also less knowledge of how to use them, and changes to the aero model and stuff generally meant the game got easier over time. Eve SSTOs used to be impossible, until we figured them out. Now Eve is just another place. A hard place, but just another place. Maybe Jool can take up the torch that Eve once held now that it is possible to land on it. After that little scientific detour and inspirational musing, it is finally time to go (title drop) Bring. Bob. Back! Entry was, well, a bit iffy. My quote about the skydancer from five months ago, something like "She cartwheels through the sky without a care in the world" was seen as a positive then, but with Laythe's less dense atmosphere, this is no longer really a positive. The prograde vector not caring about which direction you are pointing is a positive for acrobatics, not so much landing. I kept felling into stalls that I could not recover from, that were perfectly recoverable from on Kerbin. But eventually I got back to prograde. Any sharp maneuver near the surface, however, would disturb this, leading to a stall and a rapid crash. So this landing took many, many attempts. Better landing gear placement and more wing area in general will be a priority going forward, if not resorting to parachutes for landing. Here is one such failed landing. Here is the Skydancer assuming the Starship belly flop position. I managed to set it down here, and was braking, when all of a sudden - Also it is just now occurring to me that the "Came in a little hot" flight status message might be customized or randomized, I will pay closer attention to that going forward, as in KSP 1 there wasn't much reason to look at that menu, so I wasn't really paying attention to this one. Remembering how well this thing handled water landing, I set it down gently on the very edge of the shore (or accidentally overran the beach and ended up in the water, I don't remember) and finally landed intact! The engine was then lit to push the Skydancer over to the HydroHopper. And Bob Kerman is greeted, of course, by Bill yawning. "I could do that in my sleep!" he said. The two exchanged hugs, laughs, and jokes, before entering the Skydancer and preparing for takeoff once more. Another side note, wow. That cockpit is incredibly detailed, I guess as futureproofing for when IVA gets added. That's going to be so cool to sit in there when it is added. I wonder when someone's gonna get a VR mod up and running. Not that I own a headset, but I will borrow someone's at the earliest opportunity to experience that. Bob, not really missing Laythe, and Bill began the takeoff procedures and began the takeoff eastwards. Triumphantly, the Skydancer lifted off, but all was not well! No matter what Bill did, the Skydancer just wouldn't climb! They considered aborting and attempting a landing before they hit the high dunes in the distance, or even attempting a dangerous slow turn towards the ocean for another water landing, before finding the root cause of the problem: The RAPIER's thrust limiter was still set to 44%! I don't remember exactly why I set it to that, but my best guess is that it has been set like that all the way since the initial Kerbin ascent, where I would have messed with thrust limiters to keep the shuttle-like asymmetric launch vehicle balanced. After the thrust limiter was corrected, the Skydancer soared like a rocket into the sky. Ascent from that point proceeded without issue, although top speed was a bit lower than expected due to a combination of different performance expectations held over from KSP 1 rules of thumb, and my not great ascent profile. Jool rose over the horizon. And orbit was entered. Unfortunately, the game may have also glitched here, I think this is similar to the KSP 1 bug where the craft still thinks it is landed. I don't remember the details as it has been five months, but I think I was prevented from time warping. Either the velocity would drop to zero when I tried, or it wouldn't let me, so the rest of the rendezvous had to be performed with the jetpacks. More lovely EVA boots goodness. The docking adapter for the HydroHopper was detached, and the ISS Infinity was all by itself now. I don't remember if I transferred both Kerbals, I will have to check before flying home. The ISS Infinity still sits in Laythe orbit ready for whenever I have the time to fly it home. This is, however, where the 0.1.3 sceenshots end. A quick comparison: 0.1.3 clouds 0.1.5 clouds (Not exactly a fair comparison as one is much further away but the point still stands). Blackrack is a wizard. KSP 2 seems... A lot more emotional so far than KSP 1. Mood music, more stunning and emotional visuals, more expressive Kerbals, and that EVA magnetic boots thing I still can't figure out why it makes me so emotional... Having done a decent amount of software dev work for a college project, I understand a fraction of what the devs are going through with squashing all these bugs with interacting systems. I can't deny that the launch and a good chunk of the PR surrounding the launch was quite suboptimal, putting it lightly, and the fixes took longer than I expected, but most of the bugs I encountered so far on this mission are either fixed or imminently being fixed. In that time, graphics and performance have both improved somewhat for me. There's still a long way to go, but I think that, as long as they don't get rug pulled by the publisher, this game is going to be just fine.

Well, I got TOTM! Last time I got TOTM was probably with Voyage and the whole month went by without me posting, but this is a lot lower stakes and somehow I have some time so ehh whatever I'll post the stuff I had done a few months ago. This is all still either on 0.1.3 or 0.1.4. Performance has improved for me since then although I think I'll need to buy an SSD to appreciate this game properly as scene to scene load times are still very long for me. Every good mission needs a mothership! This is the ISS Infinity, which will carry everything to Laythe. Well, it would if it wasn't for the curse of wobbly rockets! After a quick revert and some extra struts, the Infinity was once again ready to go. Booster sep. And, orbit! Tied for first place in my KSP 2 feature list is the magnetic EVA boots. The other item in first place is Blackrack's new atmospheric retouches, it makes the game so beautiful (none of that will be in these 0.1.3 or 0.1.4 screenshots though). I know they aren't particularly realistic, but they just add a certain something. In KSP 1 I could EVA fly around the ship and look down at the planet below and think "Wow!" but something about also being able to stand on the ship while doing that makes the whole experience several times more impactful. I don't remember if it was this mission, but I have definitely teared up looking down at the planet while attached only by using magnets. I still can't pinpoint the root cause of why standing on something is more impactful than floating, but it is something I will continue to consider. Next up is the launch of the Skydancer, sans pontoons, as we are now going for a land landing. Boosters flexing on us, the showoffs. I was eager to test out the new to me at the time vacuum engines, unaware of how little thrust they actually had. My brain saw the isp and went "OOOOOH MONKE LIKE ISP" and did not take into account the notion that maybe I did not have enough thrust to enter orbit. The good news is that it can survive re entry just fine! A side note related to ISP: Once KSP 2 gets stable enough to do grand tours and low mass challenges like in KSP 1, I am very excited for the relative buffs of the ant and spider motors relative to KSP 1. When you get down to incredibly light stuff, ISP almost ceases to matter as the next largest engines are several times heavier. For some reason, the devs decided to buff the Ant, already the best engine for the job for small stuff, from 315s of vacuum isp to 330! I am unable to find any gimbal information, but some part of me thinks they may have also added gimbal, but I'd have to check, don't quote me on that. Xenon tank mass ratios were also buffed and I think they have the same mass ratio as liquid fuel tanks. In KSP 1 the mass ratio was awful, this will also help low mass missions a lot, although with the lack of EVA construction for the forseeable future, lack of reliable propellors, and less knowledge of aero exploits, the record will remain significantly higher for a while or maybe forever. Still, a lot of interesting buffs to small craft to think about. With that mostly unrelated tangent out of the way, the replacement Skydancer launched, with one of the next size up engine instead of two of the smaller ones. It made it to orbit without issue and will proceed to Laythe under its own power. Next up is the HydroHopper, on a much more conventional launch vehicle. Launch went without incident. The captain (It might be Jeb, I don't know. EVA suit nametags would be an interesting thing to have to make keeping track of Kerbals in screenshots a lot easier for mission reports. However, we can't just send an unbalanced ship to the depths of space! (Although with time warp under acceleration and lack of persistent rotation, you might actually be able to do so now) To counteract the imbalance, a probe was launched to - Aaaaaaaand it flipped because small fins. Attempt number 2! A probe was launched with the aim of descending into Jool's atmosphere. Second stage was Poodle powered. The probe approached and docked to the ISS Infinity without incident (A side note, if possible I would love LF+O multi directional RCS thrusters. They would probably have to be heavy to not disincentivise normal RCS use but I don't like how I have to spam the single direction vernors for multi axis control. The ISS Infinity is now ready for departure! With time warp under acceleration, this should be a breeze! Unfortunately, I then ran into this bug: And didn't notice it was happening until I had burnt a lot of fuel. KERB says that this will be fixed as of 0.2, hopefully they caught all of the causes! But for the meantime I had to execute some corrections and sit through a painstakingly long burn. I had also designed this ship with the ultra low thrust but crazy isp vacuum engines, so this was pretty painful. The same procedure was executed with the Skydancer and its crew of just Bill. I can't wait until this whole time warp system works in combination with this maneuver system, because I love what they are trying to do with the non impulsive maneuver planner. Should lead to significantly less pain for new users going interplanetary once it is completely functional (and also supports maneuvers for fuel you don't have or thinks you don't have). Off to Jool! The Skydancer is the first to reach Jool. It also experienced the "Eye of Jool" bug, which I think but I'm not sure is either fixed by now or will be fixed in 0.2. I recall reading about it somewhere but I can't find it right now. Clouds were off to preserve performance, less of a problem in 0.1.5. Laythe normally looks cooler. Turned clouds on for the actual landing though, and another magboots shot! Also showing off another bug that is fixed/is being fixed, the extendable nozzles retracting upon save load. The Infinity followed in short order. Both ships abused Laythe's atmosphere and the lack of re entry heating to enter into Laythe orbit with minimal fuel expenditure. The hydrohopper was undocked and sent down to the surface. De orbiting it in the right spot to reach Bob and the nearest shore with the rather limited amount of fuel on board took several attempts. This thing does not fly very efficiently. I bet Bob was very happy to see this after bobbing up and down in the Laythean ocean for several years! An interesting (but inconsequential and not worth it) feature would be ocean currents that work under time warp, if you get stranded at sea, after a few months or years you might wash up somewhere. I don't advocate for this being added, as it would be complicated and more of a hinderance than a help in most cases, but it is interesting to think about. Bob, very glad to see a ship, swam over to it. The HydroHopper took off into the sunrise towards the nearest patch of land, which fortunately was flat enough to land the Skydancer at (not very hard, KSP 2's terrain seems to be a lot less vertically exaggerated than in KSP 1, AKA I miss the ridiculously steep peaks to the west of KSC). With plenty of fuel remaining after a pretty spot on earlier landing (again after several attempts), Bob set the HydroHopper down near the shoreline. And at long last, the first Kerbal set foot on Laythe.

Is a weekend launch a possibility or are they not allowed to do that, I forget? Every day after Saturday the 18th until Monday the 27th is wide open, but Friday could be complicated if it happens in the evening. If it goes up on Friday I hope it is before 5:40, I work then. Sadly it isn't a job where I can have my phone out (bus driver).

I've played some more but I bit off more than I could chew this semester and haven't been able to post it. When I do have free time I usually just want to go back to bed these days.

May I ask if there has been any progress on wings deforming upon save and load? This is probably one of my biggest hangups at the moment, being able to use a craft long term without it getting krakened and the feeling of history that comes with doing so is important to me. In general I'm glad to see that progress being made.

Yeah, I'm recalling what a headache it seemed to be when that happened with Falcon once.

A bit off topic, but this is definitely going to show up in fanfiction and it's going to have it's own lore. I cannot recall a more visually distinct and interesting graphics glitch in all of KSP history.

(Rant deleted by me) TLDR: Life is very full right now, I don't even have enough room for life, much less project intrepid. It might come back some day. I am very exhausted and know that this next year will probably only be harder. I am very glad that people still like my stories after all this time, thank you for expressing that, but please be patient. It is just as hard on me not being able to make more as it is on you not being able to read more.

A few million dollars plus a few years of engineering salaries (for just one of these satellites) is quite the crowdfunding campaign and I'm dubious that anything beyond a cubesat designed and built by unpaid volunteers could be reasonably done for the purpose of amateur astronomy, at least with the kind of money that is likely to be collected.

My understanding is that during steady state observation, Starlink is essentially invisible. Not sure how far that invisibility will last against a 10 meter telescope, I would love to see data on that. While maneuvering (especially right after launch) they are still very bright though, that's a harder problem to solve.

I don't think the issue is that the FWS has a say. I think the main question is why they are being brought in now and not earlier. An item with a four month lead time should have been started four or five months ago, so why did it slip through the cracks until now? Is this a "Surprise! We, the FWS, need four months to review this and we didn't tell you until now!" situation or a "We, the EIS guys, did not include the FWS stuff in the requirements" situation, or an "Oops, we, SpaceX, forgot to involve the FWS until now" situation? I don't know if I can assign blame until I know if this is a SpaceX thing, an EIS thing, an FWS thing, or something else.

Case in point: https://www.faa.gov/newsroom/faa-closes-spacex-starship-mishap-investigation Update from SpaceX website: Interesting, primary cause of failure was fires in the engine bay, N-1 style. From what I saw, the primary problem was suspected to be in the hydraulic system, by the public at least..

Man, and to think I thought we had a chance at Mars in 2024 when young me saw the IAC 2016 presentation... How young and naieve I was. A preliminary design review of depots in Q3 2025 does not bode well for HLS.

I don't have a source for this but I seem to remember seeing that the "50% by X date" sort of thing is designed to prevent spectrum hoarding. As long as Blue is making a good faith effort to utilize the spectrum, being a few years late shouldn't be a huge deal.