Ultimate Steve

Here's my 7:39 or 7:42 run depending on how you count, in a ship I call the Pluto I as it kind of looks like a Project Pluto missile. My strategy was to try to get as close as possible to the Rapier speed limit of Mach 5. Mach is higher lower down due to the higher temperatures, so the lower you go, the faster you can go, but then you run into heating issues. I attempted to make a decently thermally resistant craft using creative though not excessive node routing, without going into straight up total thermal/aerodynamic occlusion tech. There is an additional bonus from flying low, the total distance traveled is shorter because the world is round. The vehicle in question. The Vector is responsible for rapidly accelerating the vehicle to about 1000m/s, which makes our time faster, allows the Rapier time to spool up, negates the need for landing gear, and gets the Rapier into the regime it works best at, avoiding the transonic doldrums. After it is out of fuel, the Vector is jettisoned. The fuel tanks and engine are shielded from aerodynamic and thermal forces due to being in a fairing, and the forward fairing, heat shield, and intake are routed in a way where it is pretty aerodynamic and the heat shield takes the brunt of the heating, while still allowing the intake to work, though this is a little cheesey. The first challenge is clearing the mountains and not going too high. The next challenge is heat. If you wanted to, you could probably do the run without the elevons with a redesign, but the elevons are the limiting factor right now because you can't stick them in a fairing. 2-3km seemed to be the sweet spot, but I had to constantly manage throttle to keep the elevons from melting. A few runs were ended because of this. Due to the adjustments required and the 1 degree resolution of MechJeb, at one point I tried 2 elevons in the middle to act as adjustible wings with the deploy function, but they melted very easily and were removed. I was able to keep a cruising speed of roughly 1820m/s for the whole thing, up to 1830 at times, with the elevon overheat indicator between 99 and 99.5%, although the average was definitely slower as I frequently cut the throttle in a panic when the heat rose too high, and dipped down to the 1700s for a while, taking some time to recover. The Pluto I is slowed down by blowing the fairings. I blew them a bit early here, so early I had to go to full throttle and pull all the way up to just barely reach the runway. The parachutes are deployed in 3 stages. There's a drogue, which allows you some amount of engine control if you over or undershoot (the sideways runway is a very small target in this axis), the first main, which lets you pick your landing site for good (engine control can't do much after this point), and the other 2 mains, which were supposed to be deployed right above the ground to cushion the impact. Unfortunately, I came in too fast and deployed both of them early to slow down, so there were several seconds of falling. Touchdown at 7:39. Stable on the ground at 7:42. This design can be improved perhaps down to 7:10 with better piloting - I did a very conservative approach and slowed down way too early. You can probably pass over the runway at full speed at 7:00 (no slowing down for landing). There's not much better you can do with the Rapier alone without doing actual thermal exploits and I don't think that's within the spirit. I suspect that this design is near a local maximum, and that the optimal design for the challenge is a gigantic booster pancake that goes high enough to avoid heating and drag.

This could either go here in the MSR thread (wait hold on, do we have an MSR thread?), but since we are talking MSR already I thought I'd bring it up, as the subject matter is both MSR and Red Dragon/SpaceX related. https://news.ycombinator.com/item?id=26274117 That's an old post from someone who was working at NASA around the same time as Red Dragon was being proposed for Mars Sample Return. While it is an anonymous personal account and should be taken with at least a few grains of salt, if true, the contents are interesting. The OP discusses how company and government politics and not internal cancellation prevented Red Dragon from happening. I recommend reading the whole thing. TLDR, if the person who made this post is to be believed: SpaceX proposed (or planned to propose) Red Dragon 3 times The first attempt (2013) was not a sample return and was shot down by NASA/the government (rumor) Falcon 9 had only flown 4-7 times at that point depending on when in 2013 we are, SpaceX was very much still the underdog NASA didn't want a crew rated capsule to be seen going to Mars and propulsively landing when Orion couldn't do any of that The main rumor is that some higher ups in the government (think shelby types) threatened to withhold future CRS and Commercial Crew and other contracts (which SpaceX was very much trying to get) if Red Dragon happened The second attempt (2014 or 2015, post uses both years) was a sample return but was shot down by JPL JPL is protective of their role in planetary exploration JPL had previously scheduled their missions to assure a steady stream of funding JPL did that with MSR as well, the fact that it is 3 missions is part of that MSR going to anyone other than JPL would be a severe threat to JPL's prestige and funding JPL tried very hard to discredit Red Dragon via numerous (often underhanded) methods OP notes that neither proposal was actually submitted, and posits that there aren't many other reasons why you would prepare a proposal and not submit it OP doesn't know much about the third attempt (2016) Obviously it didn't happen This is when SpaceX pulled the plug and decided to go all in on Starship (ITS at the time)

Given the MSR news... I'm not saying this is a good idea and I'm not saying it will happen, but proposing a manned Starship mission to complete Mars Sample Return is a completely on brand thing for SpaceX to do. Would be quite the plot twist but the 21st century of space exploration has been filled with so many plot twists already that I doubt anything would surprise me at this point.

The guys making the Delta IV had to exert so much mental fortitude to resist calling it "Phoenix" after its pyromaniac tendencies, so that the superior joke of there being a Delta V could happen someday, only for there to never be a Delta V.

Really? Where specifically? Lorain County Ohio

I saw it! Clouds covered nearly the whole sky in Ohio, but they were thin and high enough that we could see right through them. Pictures coming later maybe. Was really cool watching the sky change colors, especially right before totality ended, like a really fast sunrise but in an unusual spot!

In the recent presentation Elon says they are not working on Mars propellant production yet. This almost directly contradicts Tom Mueller's claim that he spent his last 5 years at SpaceX working on ISRU. One if the negative nancies on the Discord is saying this proves that they stopped working on ISRU after Tom left. I don't want to accept this but this is the only way to reconcile both sentences if we take both statements at face value.

There were also slides showing up to date thrust numbers and such. No isp or dry masses, sadly, but might be able to reverse engineer some of those numbers from telemetry.

I don't know, actually. I felt it working but it could have just been placebo. I haven't done any rigorous testing on it, I'll add that to the list of things to do.

Ultimate Steve's Kerbol System B-Sides Hello everyone! The Kerbol System B-Sides mod is a set of Kopernicus configs to adjust the stock system to provide interesting navigational, piloting, and engineering challenges, while ramping the characteristics of each world up to 11. This mod is inspired by the B-sides from the game Celeste. Each level in the game (except the last one) has a B-side, an optional non-canon remix of the level with increased difficulty, largely keeping the same theme, expanding on what made the original challenging. There are also the C-sides, which are even harder than the B-sides. This mod was created because I found that the stock Kerbol system had gotten a bit too easy for me. Rescales and hack gravity challenges really only increased one or two dimensions of what made things difficult, and the planets were still largely unchanged. Planet packs are largely based around stock difficulty, and RSS/RO/RP-1 can get to be a bit too much sometimes. When I first started playing KSP, everything seemed impossible. Then I gradually learned how to do everything, to the point where I now know you can do a grand tour in under 8 tons. I used to plan for weeks how I would get to Duna, and I would be so elated when I finally got there. Now, I just simply go to Duna. This mod aims to restore those senses of impossibility and accomplishment while still remaining possible with stock parts (probably). The difficulty tuning is roughly based off of the Mun being a bit easier than stock Tylo. Not every world is scaled exactly like this, but that is the general idea. Brief Descriptions Without Many Spoilers (for those who would rather discover the challenges themselves) All of the details More Pictures Known Issues (I am accepting help) Development Outtakes Installation Install Kopernicus Planetary System Modifier and its dependencies via CKAN. Install BetterTimeWarpContinued via CKAN. It isn't strictly necessary but it will make ion burns far less painful, and will eliminate any problems from vanilla time warp limits still being applied on smaller bodies. Install the latest version of Sigma Dimensions from GitHub (https://github.com/Sigma88/Sigma-Dimensions). The version on CKAN is not up to date (was made for 1.3.1). I'm unsure if the version on CKAN will work, it's best not to chance it. Install the Kerbol System B-Sides mod from GitHub (https://github.com/UltimateSteve99/KSP-B-Sides) (License: MIT) (Also has source code) by unzipping the folder and copying the contents of GameData to your installation's GameData folder. A mod such as J2X antenna is also recommended as the stock antennas likely won't work when Eeloo is at apoapsis. Kerbal Joint Reinforcement is also recommended as rockets can get quite large. Other legal stuff: Some code was taken from the Kittopia Dumps. As far as I can tell, the Kittopia Dumps license allows that, and I think that's all I need to say, if not, let me know. Advice This mod is not meant to be played in career mode, things will probably not work (some biomes may become inaccessible, etc). It is recommended to play in sandbox mode, but science mode is likely doable by increasing the rewards sliders. Everything is balanced around an experienced player using stock + DLC parts. Every world is intended to be possible, though some of them get quite difficult. I have playtested a bit, but I haven't tested everything. If you find a bug, or if you think something is balanced incorrectly, let me know! While each world is surmountable in a bubble, the sizes of the rockets necessary to launch them, even in pieces, may exceed reasonable limits. If that is the case, I will rebalance things. Where are the C-sides? The C-sides will be worked on once every B-side world has been conquered with stock+DLC parts. Visual and informational mods are allowed, MechJeb parts are allowed, bigger antennas are allowed, the only two physics mods allowed are BetterTimeWarpContinued and Kerbal Joint Reinforcement. If Eve, Jool, or Tylo end up being impossible, I will rebalance them to be more reasonable. Let me know if you do anything cool in this mod, or if something is broken/way too hard!

Material lifetime curves are unpredictable and vary based on lots of things (material, temperature, stress, amplitude, cycle count) and are usually empirically tested for rather than calculated. I don't think you can extrapolate rules of thumb like that. I'm not the most knowledgeable about this (Haven't even finished Aero undergrad, I guess you could say I technically specialize in command and data handling and spacecraft communication and not propulsion or structures), but I don't think rules of thumb can be applied like that to something so complex. There's going to be three types of wear that I can think of. Creep, fatigue, and wear. Creep, deformation under constant load, is like if you took a blob of silly putty and hung it from something and watched it stretch. Any well designed propulsion system designed for long term reuse, jet, rocket, or otherwise, will (if I am being sensible and know what I'm talking about) not operate in the creep regime. You can operate above the creep limit for a short period of time and have things not break. Non reusable rocket engines such as the RL-10 will do this to enhance performance, as they only need to run for a few minutes. In this case, reducing power can drastically prolong engine life, taking it from a few minutes to practically forever (or until something else fails first). I can't imagine that Merlin has this problem. From what I remember, for a given temperature there's a sharp cutoff where creep doesn't occur. Increasing stress beyond this point will quickly decrease time until failure. The engines that do this, I'm pretty sure only do this with the nozzle/maybe combustion chamber and not the turbopump, as you can't have a precision component like that changing size throughout the burn without causing major problems. I could foresee a future in which "emergency power" is available to reusable rockets, where an engine can slightly increase in power for a few minutes to compensate for other losses, at the expense of the rest of that engine's operational lifetime. Then there's fatigue, weakening due to repeated cycles of stress, like if you took a paper clip and bended it back and forth repeatedly until it broke. Some metals are susceptible to this at all stresses, some metals have an endurance limit where you can do an infinite number of cycles as long as you remain below a certain amplitude. The alloys in jet engine and rocket engine turbines are crazy stuff and the graphs for them probably aren't available online, but the factors in the equation are stress amplitude and number of cycles. Rocket engines haven't yet gone through a lot of macro cycles (startups and shutdowns), and many graphs aren't even available for numbers below 1000, so macro cycles probably won't be an issue. Micro cycles, like a slightly unbalanced turbine spinning, or something vibrating, could be an issue if the stress is high enough or they are using a material without an endurance limit, as those things go through a lot of cycles. Fatigue failure of rapidly spinning jet engine components has been a major cause of aircraft crashes, but reducing power would indeed dramatically prolong the life of the engine... However, this timeline is generally measured in years, today's reusable rockets have total runtimes measured in hours. And then there's wear, either by friction or slow burning chemical reactions with the hot propellants, or through other means. I'm not well versed here, and I'm not sure if any rocket engine has run long enough to properly characterize these phenomena in these environments. The above phenomena generally manifests over very long engine runtimes (think months), reusable rocket engines currently have runtimes measured in single digit hours. It isn't impossible for it to run fine for 10 minutes and then fail on minute 11 due to fatigue or creep, but I would be very surprised if that is what's happening. It would require either devious new failure modes almost nobody has run into before (e.g. flammable titanium, solid lox) or unbelievable stupidity for the leading experts in reusable rocketry to aim for something that runs for days with thousands of cycles to fail in 5 minutes 2 or 3 cycles in (excluding those tests where they push it further to see how high they can go and where it fails, like those tests where they push Raptor to ridiculous chamber pressures). I don't think Raptor has a massive widespread reliability problem right now, we haven't seen many failures that weren't related to the fuel feed system. But if there is a widespread Raptor reliability problem, it almost surely isn't directly the fault of the design being too close to fatigue or creep limits. Merlin did indeed have fatigue issues early on, a few came back with (presumably fatigue) cracks at the beginning of the reusability era, but I haven't heard anything about them in years (likely pre block 5), and to my knowledge, they have long since been fixed and didn't ever cause a failure (although IDK if we ever found out the exact reason behind the CRS-1 Merlin failure).

Beautiful vehicle, a marvel of engineering and an excellent first step towards rapid reusability and a sci-fi future, that we stuck with for decades and never got followed up with a second step. The bulk of the troubles people tend to have with it is the gap between what it was billed as being able to do and what it actually did. Most of its turnaround, reusability, and cost goals were never reached. I'm all for aiming high, but you can't get something that ambitious right on the first try. Going from Apollo to 2001: A Space Odyssey in one step was never going to work, but they tried to get close with the one try they were allowed. We ended up with something that was promising but not particularly revolutionary. Instead of iterating on the shuttle (well, they did minor iterations), we kept the same design for 30 years and never committed to properly funding replacements or upgrades until after it was gone. This was however largely a funding/political problem, though.

Grammatically, full duration can be both in reference to the test duration and the mission duration. It can mean both things. Maybe there should be different terms for the two, I don't know. Simply saying full duration is shorter, and we have seen that saying in 2 places. Twitter/X and in mission control speak, both of which are places where brevity counts. I think Exoscientist might be concerned about SpaceX deliberately and maliciously using this ambiguity to mislead. Maybe a dumb investor would fall for that, but nobody in the know would see "full duration" next to a video 20 seconds long and think "gee, I should buy a mission from them because they are firing the upper stage for a full 8 minutes/their upper stage is so powerful, it can enter orbit in 20 seconds!" Now if they were specifically claiming full mission duration, that would be cause for alarm.

Hmm, looks like they did. Memory is a weird thing.

I wasn't aware that they could safely fire the Vactors at sea level.

Is this speculation credible? We do know they had to at least have enough propellant on board for the prop transfer demonstration, the contract specified at least 10 tons and they probably had more left, as they had planned to relight an engine for a few seconds, though they cancelled that due to bad angular velocity. That's not a lot but it is a lot more than zero. On IFT-2 they had too much propellant (likely a re-entry constraint and they didn't want to vent it in orbit for whatever reason) and venting it caused the failure. I don't remember if they dumped on ascent during IFT-3 or not, but if they did it would give the illusion of Starship barely making orbit. Or maybe they found some other way to burn fuel (Gimbal Raptors all the way out for cosine losses, early stage separation, etc) to not have to vent stuff at all. If this speculation is true, V2 Starship is right around the corner and the V1 ships being a little overweight probably isn't the end of the world.

@Exoscientist on the Artemis thread, you were talking about how to best utilize Starship to carry payloads to the Lunar surface. I had originally written this for that thread but right as I was about to post it, the mods said to stick to Artemis stuff, so I'm posting here instead as no Artemis payload is as large as the numbers I'm working with. As I'm about to post this, I just realized that, for some reason, I had jumped to cost per ton of cargo to the surface rather launch than cost per mission. If you are thinking cost per mission, you can ignore the rest of this post as I may have made a bad assumption. Under the new assumption of a single launch of an Apollo-style mission, then yes, the launch costs of a fully expendable Starship with reasonable assumptions (as described in scenario 3) would be lower than the launch costs of a fully reusable Moon-and-back Starship, but then you have to make the expendable Apollo-esque hardware cost less than what the difference would be, which would be a challenge. Nevertheless, I spent too much time on the cost per ton analysis to throw it all away, so here is that analysis: There are four valid mission profiles I can think of: Single launch expendable Starship + Super Heavy Single launch expendable Starship, reused Super Heavy Several refueling launches, 1 expendable Starship that stays on the Moon Several refueling launches, 1 reusable Starship that comes back from the Moon And I am unsure which two mission profiles you are comparing. I have analyzed three (was originally two) of them below: The expendable Starship and expendable Starship+Super Heavy analyses were effectively combined into one optimistic one using the everything expendable payload numbers but the just Starship expendable cost numbers. Even with the incredibly optimistic numbers for the expendable version and more pessimistic numbers for the semi-reusable version (normal numbers were used for the fully reusable version if you didn't read the analysis), refueled Starship always was capable of getting more cargo to the Lunar surface than single launch expendable Starship. For cost, discounting the crazily optimistic zero cost zero mass hydrolox lander I had included for comparison, the analysis, heavily weighted in favor of expendable Starship, gave a cost per ton of 1.6 million dollars per ton to the Lunar surface for expendable Starship and 1.27 million dollars per ton to the Lunar surface for reusable tanker, expendable lander refueled Starship. I used the most outlandish numbers we have and semi-reusable still came out cheaper, so I can only assume Exoscientist was comparing to fully reusable. I did the third (fully reusable) analysis mostly to compare to semi-reusable. The optimism level is what I would call realistic as when I tried to use the pessimistic numbers, Starship couldn't return from the Moon at all, even to the Gateway orbit (starting from LEO at least). I found it interesting that with the cost numbers used, it is cheaper to expend the lander even with the pessimistic numbers (for starters, that 150t dry mass could be stripped down as that was originally chosen assuming it would come back but it ended up not being able to to the analysis was swapped to expendable). I didn't expect this to be the case. Fully expendable vs fully reusable wasn't my intention when creating the third analysis, but for completeness, expendable only just barely edges out reusable in cost per ton with all of those ridiculous assumptions (1.6 vs 1.8 million per ton) and in reality, reusable would almost surely win, but having to conduct fewer launch operations might make it an attractive option (if the numbers were actually physically possible). I'll also reiterate that the 800m/s elliptical orbit is a number I chose from thin air because it sounded alright, I'm doubtless of by at least a hundred or two m/s from the optimal, it is possible that fully reusable beats the hyper-optimistic fully expendable profile with a more intelligently chosen parking orbit because it is only off by 13% or so. TLDR, with current cost numbers and my assumptions, unrealistically optimistic expendable is barely cheaper per ton than realistic reusable. Unrealistically pessimistic reusable-tanker expendable-lander beats both of them by a significant margin, also leading both in payload per landing. With these assumptions, it makes sense to use expendable Starships for cargo, but reusable Starships to transport crew back and forth (and to return samples) are not that much more expensive.

That's got a lot to unpack. If my take is worth anything, I offer it. My dispute is that Starship was never really expected to be reliable three flights in. Arguably, in terms of flight count, it is doing better than expected. Starship is arguably aiming a lot higher than any other rocket in history. They want a cheap, reusable, rapid turnaround platform that can refuel in space and send people to the moon and Mars. That was widely considered a pipe dream upon announcement in 2016 and still is by many. Nobody thought they would get it right, let alone the first try. SpaceX knew this. You can't make something that revolutionary and expect it to be perfect the first time around. The space shuttle, a much less ambitious system, put a LOT of effort into doing things right the first time, and just barely succeeded (the mission anomalies section on the STS-1 Wikipedia is so long that I don't want to go through it here). The Littoral Combat Ship program is another example of this, it tried to incorporate a laundry list of revolutionary technologies at the same time, and now a lot of those brand new ships are being decommissioned because they don't work. SpaceX understands that you can't do something that revolutionary and have it go right the first time, so instead of putting all of their eggs in one basket, they built not just iteration, but rapid iteration, into the design process. The Space Shuttle was crew rated from the start, and each vehicle was so expensive that any design changes you make can't be done by scrapping and rebuilding, they have to be built into the vehicle. Thus, if you found out something was wrong with it, your options for fixing the problem were rather limited. The LCS program is working on an improved second batch of ships, but they are coming along fairly slowly. This focus on iteration also allowed them to be a bit riskier with their design decisions early on. Ideas that might work were actually tested, as the worst that could happen was waiting for the next vehicle to be done. While exactly how risky is the best amount of risky is a topic of contention, they have learned a lot about what is needed vs what isn't needed, and disproved some assumptions nobody has really challenged since the beginning of the space race. The end result of this is that immediate success is not the expected outcome. Three failures is eyebrow raising but not necessarily the end for any other conventionally developed rocket. Falcon 1 failed 3 times before succeeding and look where SpaceX is now. The Firefly Alpha failed twice before its first success (then promptly failed again) (admittedly 2 partial failures which placed the satellites too low to last more than a few weeks), and nobody is saying Firefly is dying. As for how many failures it takes to doom a rocket, Astra's Rocket 3 failed four times (six if you count suborbital tests) before getting to orbit. It then proceeded to have 2 more failures and 1 more success, failing on 3/5 of its customer serving launches before going bankrupt. That is what is required to doom a rocket if you don't have strong financial backing. 3 failures before succeeding is not that unexpected for any normal rocket, much less the most ambitious rocket in history which was intentionally developed in a way where more failures than average were expected. My dispute is with the idea that Starship can only barely go to sub orbit, and with the idea that there is a meaningful engineering difference between a vehicle that can reach the type of sub-orbit they are doing and an actual orbit. Had IFT-3 been a Starlink deployment flight it likely would have succeeded in deploying Starlinks. It made it to the planned trajectory (the only difference between it and orbit being a few seconds at most of engine burning time), and opened the door. It was later unable to control itself and was destroyed on re-entry, which is something that nearly every other rocket does by default. IFT-3 showed that Starship is capable of doing pretty much everything a baseline expendable rocket can do, the only issues were in space restart (which not all expendable rockets do) and long term attitude control (which not all expendable rockets do). The only reason the mission profile wasn't 100% of the way to orbit rather than 99% was likely because they were concerned about their ability to restart the engine and wanted to prove they could do that before needing to. This profile allows them to collect re-entry data even if the engine fails (or would have if attitude control didn't fail), and avoids another Long March 5 incident - a few years back on the early Long March 5 launches, the core stage makes it all the way to orbit on purpose and passively de-orbited. As the landing site was unknown, it caused a bit of a panic as it was big enough for parts to reach the ground. A larger and more robust vehicle already designed to survive re-entry would be far worse. I do know why they are shooting for orbit (or near orbit at least), they have proven they can do the prerequisite steps and are ready to test out re-entry and in space operations. My dispute is with what the expected fix duration is. May I ask what you are comparing this to? Seems pretty fast to me. There are two parts to this, turnaround time between launches and development time. Starship had 212 days between flights 1 and 2, and 117 days between flights 2 and 3. That includes the time needed to fix everything both physically and regulatorily. For Saturn V those numbers were 147 and 261 days. For the N-1 it was 132 and 723 days. SLS has yet to have a second flight after 493 days. While this sample size is too small to determine much, the numbers are in the same order of magnitude. Comparing to other things SpaceX has done, Starship is very fast. Falcon 1 took a year between 1-2 and almost a year and a half between 2 and 3. Falcon 9 was 7 months from 1 to 2 and a year and a half between 2 and 3. Falcon Heavy was 14 months between 1 and 2, and about 2.5 months between 2 and 3. On the development time side of things, Starship on average is taking about twice as long as expected using the targeted timeline from the Q3 2016 announcement. The details are quite cluttered so are in a spoiler. A 2x schedule slip isn't unusual. SLS was funded in 2011 and targeted a 2016 debut, taking 2.2x as long as expected. JWST design started in 1999 targeting a 2007 launch. While there were a lot of redesigns, taken at face value this is a delay factor of nearly 3x. The state of Falcon Heavy was nebulous for a long time, but was mentioned in 2008, and by 2011 they were targeting a first flight in 2013. This is a delay factor of 2x to its first flight in 2018. I'm tired of doing math but I remember a time where New Glenn, Ariane 6, Vulcan, and H-3 were expected to be online in 2020. Just now in 2024 we finally have 2 of those. Maybe the reusability program is taking longer than expected? Falcon 9 is probably the closest thing we have. Falcon 9 did 13 low altitude tests (grasshopper and F9R dev) plus 9 various full up landing tests before successfully landing a booster. So far, Starship has done 5 low altitude tests, 5 medium altitude tests, and 1 full up ocean landing test, for a more ambitious vehicle. The booster has done 1 fill up landing test and no hop tests. It is difficult to gauge how far along we are in comparison, but in terms of test count, they appear to be getting closer to flight readiness with fewer flights. Assuming it takes 12 flights to get to a successful booster catch and land landing of the ship, that's 23 Starship test flights compared to the much simpler Falcon's 22. My dispute: Every space agency/company advertises their rockets as the future of space travel. The shuttle was billed as a low cost rapidly reusable space tug, the SLS was supposed to be NASA's low cost flagship rocket for the next several decades, Rocket Lab and Astra were talking a hundred flights per year... On the positive end, Cygnus and Dragon were billed as low cost shuttle replacements and worked. The shuttle was indeed the future of space travel, covering several decades for better or worse. And Falcon 9 nearly reached 100 flights last year. But more relevantly, any moderate cost low refurbishment fully reusable vehicle is going to be the future of space travel. I am not convinced that in 50 years we are going to throw away our rockets after one flight like we are still doing, even with Falcon's second stage. Starship and Terran R are the only two rockets seriously aiming for that future, and of the two Starship is by far the closest one. If any rocket can claim to be the future, I think we have a winner. I won't go too much into detail because this is probably going to get moderated if we go much further, but I do frequently have major concerns about what could happen if Mars is run the way SpaceX is run. Even just how SpaceX is run. A friend of mine has a final interview there tomorrow and I am both excided for and concerned for her. I can see people accepting a high stress high reward environment like that for a couple years without a family (I will likely apply there soon, admittedly I am a bit behind on the graduation job hunt), and obviously the first Mars missions will be high stress, high risk, high reward positions crewed by professionals. But long term, Mars has to be a place for everyone. Musk isn't the only one that would be involved with the colony, though, and will likely be dead before a Mars colony gets going. For what it is worth, while it may not be fully convincing, he has condemned the tweet you are referencing as the most foolish thing he has ever said.

Speaking of, what's the plan if the rover dies? And how did Apollo manage this? For contingency you would have to remain within walking distance on one tank of oxygen (or whatever else the limiting factor is on those suits) anyway. Seems like you would want two self driving rovers or a simple backup apollo style rover strapped to the main rover.

I'm reading "A future Starship" as, like, a Starship, the only similarity to Starship-Superheavy being the name. To me this doesn't read like "We are going to send Starship to colonize Alpha Centauri", instead reading like "If everything goes well, eventually we might be able to go interstellar with a different design ." Which is still more than a little crazy, but I kind of admire that they don't plan on stopping at Starship. I've said it before and I'll say it again. They could have stopped at Falcon 9 and made bank and be remembered as heroes. Instead they are working on a Mars colonization rocket. That sounded almost as crazy back in 2016 when they announced it. Granted, they aren't gonna get there on chemical fuels, so unless Musk has a stealth fusion startup we don't know about yet...

I'm hoping for interstellar to offer some new worlds with new navigational, piloting, and design challenges. Eve used to be the final boss of KSP, with Eve, Tylo, and Moho perfectly representing the design, piloting, and navigation triad, but after enough times going there and back it kinda doesn't feel that challenging any more. I forget what it was called, but I'm looking forwards to that new super Tylo they have teased, and that binary system. I am a little bit worried that all the sci-fi technology they are going to add may remove a lot of what would have been a challenge, but inevitably I'll fall back into going for the low mass records and it won't be mass optimal to use any of the super heavy advanced engines. The grand tour record in KSP 1 is under 8 tons at this point, and there's been talk of pushing it low enough that we might not even need the Rapier any more. Speaking of which, when KSP 2 gets stable and polished enough for the low mass leaderboards to take off, the meta is going to be interesting. The ion engine was nerfed a LOT in KSP 2, you can't really use it to land on most of the small bodies like you could in KSP 1. Without a high tech lightweight replacement, we're going to see a lot of ultralight liquid fuel craft with opportunities for per body customization (although without EVA construction, this is docking port constrained), which should hopefully lead to a more interesting design than "Use the same ion lander for everything except Duna, Laythe, Tylo, and Eve."

Some thoughts. Booster: I think Exoscientist is referring to the downcomer crushing issues they were having a few years back? It is possible that the tail end of the boostback burn produced high enough acceleration to crush something and cause a leak or loss of pressure. It was more or less confirmed that IFT2 Booster RUD was caused by Raptor LOX starvation. There was one Raptor ignition failure on boostback, which we don't have the specifics behind, but was probably a Raptor issue. It looks like they were planning on starting all 13 for landing, which is bonkers, but only 3 ever lit up I think? Going from memory. My read on this is that there was a grid fin control issue (either software or hardware) that caused extreme oscillations leading to bad startup conditions for Raptor. Neither of those hypotheses are Raptor's fault, though. It is possible that Raptor doesn't play nice with impinging transonic airflow. That's the only "Raptor's fault" scenario I can come up with. Ship: Upper stage was near constantly venting/RCSing. Two possibilities, one, it was trying to dump as much lox as possible, two, something wonky was going on with controls. I am guessing that they were experiencing severe control issues immediately following SECO. The orientation never seemed to stabilize, not for payload door stuff, or maybe the engine stuff, and definitely not entry. We didn't see what Starship was doing when it was supposed to be firing its engine, but being in an uncontrolled spin is probably on the list of "Do not fire the engine" criteria and is a possible reason why that burn was skipped. Interestingly enough we see no RCS whatsoever after the camera feed was recovered for re entry. This could be because they don't want to fire hot oxygen into the airstream or something, but it is also possible that the main tank was fully depressurized at that stage - maybe there was a leak (would explain control issues if said leak produced torque), or maybe they used up so much trying to steer that the main tank pressure dropped to zero. I'm not completely sure that Starships's RCS is just vents but that's what I seem to recall it being. But in any case, something caused them to not have attitude control at some point in the coast, possibly the entire coast. I cannot imagine that it is normal to enter the atmosphere in a tumble. I am very delightfully surprised that they managed to get live video of the plasma regime! Also no explicit confirmation of successful payload door closing, there was a twang and vibration on the door then the camera cut away for the rest of the flight.

Not necessarily tile loss, the thing appeared to enter the atmosphere in a tumble. There's been some speculation that there was minimal to no control after SECO, that roll may have been coincidental and not commanded, plasma on the silver side is not normal.

Engine relight demo has been skipped.

Prop transfer demo in a minute or two. Engine relight in 15-20. Splashdown in 40.