Ultimate Steve

IIRC Dragon 2 is way more expensive than Dragon 1, and it was originally going to be offset due to increased reusability. However, now D2 has to land in the ocean, which means it's going to be harder to reuse. I also recall that there were a few NASA mandated changes that drove up dev cost. Also, there is inflation to account for. That's no small issue. Over the past ten years the USD has inflated by 16%.

If SpaceX has an RUD then they are going to be grounded for a while, realistically. You want multiple options to ship cargo in case of something like that. Or, what if one of the companies goes under? It's about having a backup.

Until 0.10.1 the atmosphere was a solid wall ending at 34,500m.

Ugh, tell me about it... Homework, then Prom, then After-Prom, then MOAR HOMEWORK, then tech week, and soon getting a job... I might have to turn to coffee.

What... WHAT... AAAAAAAAAAA FINALLY!!!!!!!!!!!!!!!!!!!!!!!!1

I wish.

Words are not powerful enough to describe this.

So, I'm a techie for the play (opens tomorrow) and I don't do much, so at rehearsal tonight I made a list of optimizable things and changes. Again, IRL we would probably use the changes for extra capability, but the thread is about lightness. Modern computer systems (duh) Modernize the instruments in the instrument ring and move them to the interstage where the LEM is stored, eliminate the instrument ring altogether. Modern electrical systems - less power hungry, better batteries, etc. Maybe change the interface to a touchscreen system, if the increased power requirements are worth the weight reduction. Update the fuel cells or get rid of them and coat the SM in lightweight solar panels. Lighter docking apparatus - ditch the crew tube entirely. Use the CM as an airlock and do EVA transfer, Apollo was capable of it (at least in later versions). Switch out the current heat shield for PICA-X Upgrade the spacesuits to make them lighter Keep the updated lander improvements but use the extra capability to remove fuel and the corresponding tankage to make the lander overall lighter. Drop the rover and most unnecessary cargo. We could go with a 1 man lander but that's outside the scope of Apollo. Update communications systems. Update Life Support Tanks. MAJOR: Change every single tank and structure except for possibly the S-IVB tank to carbon fiber, or Al-Li alloy as a backup if carbon fiber isn't current enough. Drop one of the three CM parachutes. It is redundant (for a good reason, yeah I'm getting rid of some safety features) and the lighter CM should be able to make do with 2. Make a better LES tower, with improved solids and make it lighter. Change the J-2 on the S-IVB stage to 3-5 RL-10's depending on how light the CSM/LEM end up. MAYBE: Switch the S-IVB to a balloon tank to lighten it, unless the CSM/LM are too heavy for the balloon tank structure. Add some more insulation to the S-IVB to make it last longer Change the whole paint scheme to mostly thermal reflective white MAYBE: Drop the S-IVB ullage motors, use a hot start for the first burn and pressurized gas from the stage on the others. Upgrade all RCS thrusters to modern efficiencies and manufacturing techniques. Update the SPS engine or find a replacement. Switch the cabin atmosphere to O2/N2, yes it adds mass but on the plus side you don't have to be as careful about fire protection. Lighten the boost protective cover, or if doable drop it entirely. Use a hot start for the S-II stage so you don't have to include ullage motors. You can probably get away with dropping the stage separation motors as well if you do it right. Switch to 2 (or maybe 1, but unlikely) RS-25's on the S-II stage. Don't bother with the weird S-II interstage, just leave it attached to the first stage, especially now that the nozzles are smaller and not as likely to strike the sides. Switch out the F-1 engines for less than 20 Raptor engines depending on how light the full stack gets OR use RD-170's if you want to stick with kerolox. If we use the Raptors, switch the stage 1 tankage to methalox. Drop the fins, they aren't needed. Drop the engine covers, the Raptors probably won't protrude out that far. 3D print many small parts and also use carbon fiber for many small parts. MAYBE subchill the propellants, like the Falcon 9 does. Get rid of most of the fuel baffles, they made them way too big because they didn't know as much about propellant slosh as we do now. Reduce fuel and structural margins within reason - as in, we have better computers so we can be more certain, especially the LEM's fuel margin, the computer can land it with less margin. MAYBE lower the first and second stage diameter by a meter or maybe 2. Shorten all of the fuel tanks to the necessary Delta-V requirements and drop engines as needed to preserve TWR.

As far as the nose cone debate, I'm not sure if this is more mass efficient than the nose solutions, but you could stick the whole thing in a fairing.

Well, I typed the explanation for the S-IVB stage engine choice, but then I realized that @Racescort666 was partially talking about the S-II stage... In that case RL-10s are definitely out, and RS-25 is probably a better choice than J-2X for the S-II. I won't do the math on that, though, yet, at least. Below is the math for the S-IVB engine choice, and it took me about half an hour and I need to have dinner and go in half an hour. Note that this choice disregards politics. If we do bring politics and budget into play J-2X would make a lot more sense because SSME's aren't being built and both the SSME and the RL-10 are expensive. Engine Specific Impulse Mass Thrust J-2 421s 1788kg 1033kN RL-10 465s 277kg 110kN RS-25 452s 3527kg 2279kN J-2X 448s 2470kg 1307kN As far as upper stage engines go, everything here seems to be better than the J-2, so any change is a good change. J-2X has the lowest isp of the three replacements but still 27s better than J-2, and a thrust upgrade, but 600kg extra mass. We could rescale it for the same efficiency but lower mass and thrust, but then we're making a new engine (which would be possible but not ideal). RS-25 is the heaviest and has the most thrust, let's say we rescale it to 50% giving 1100kN and 1750kg, which is worse than J-2 mass-wise, although it has better efficiency. And RL-10, if you sacrifice half of your TWR (5 engines, 550kN) gives you about 1400kg in mass for 465s. If TWR is a huge concern, you could potentially use more advanced insulation and split the TLI burn in two. Delta-V calculations, assuming 15t LM, 29t SM, 10t dry S-IVB (I subtracted the mass of the J-2) and 104t of S-IVB fuel... total of 158t, dry mass of 54t. Adding engine mass each time. J-2 - 4382m/s 5x RL-10 - 4820m/s 10x RL-10 - 4756m/s (although 10 RL-10's would not fit as pointed out above, doing comparison for the sake of having a similar TWR) 50% RS-25 - 4666m/s 100% RS-25 - 4576m/s J-2X - 4588m/s First of all, some of these engines have different fuel mixture ratios but hopefully they all are similar enough to be used for approximate numbers. Second of all, the masses shown above are without all the other improvements we are talking about adding, they are the numbers for the original Saturn V and Apollo. So, besides the original J-2, J-2X is probably the worst choice, although still way better. The full scale RS-25 would only be used for being available, as it is also not the best, although it is still great and semi-readily available. However, IIRC it is not restartable. A 50% RS-25 is a better option, and if you are going to the effort to make it that small you might as well add restart capability and remove unnecessary gimbal (lowering the mass) so the actual RS-25 50% Delta-V would be higher, maybe 4700m/s instead. At that point, the RL-10 may look worse due to the TWR problems that 5 present and the space problems that 10 presents (and more failure points, but also engine out capability), however the extra 50-150m/s might be worth the cons, because they are available now rather than the 50% SSME which is not. Plus, I checked, and boiloff between the two split TLI burns on a 5x RL-10 setup isn't actually that bad - Centaur currently boils off at about 17% per day (and they are aiming for 0.1% with ACES so that is definitely improvable), so for 2-3 extra hours in orbit that's a 2% reduction in fuel, and assuming that directly correlates to delta-V (it doesn't but it's close enough) and only half of the fuel mass is effected (the split burn) gives the 5x RL-10 4771m/s, which is better than the 50% SSME. And you might not even need five, given the mass reductions elsewhere and the fact that you have 400m/s more Delta-V than the actual S-IVB you could probably go down to four, or even three if you were feeling adventurous. Again, this is not counting politics. From purely a "MAKE SATURN V SMALL AND LIGHT" perspective, RL-10s seem like a pretty good choice. Back to the second stage, actually the RD-120 might be better than the SSME if only slightly. As far as the first stage goes, not doing all of the math, just a table. Only the Merlin is currently in production. Specific impulse is sea level, as is thrust. Engine Specific Impulse Mass Thrust Number needed (33850kN) F-1 263s 8400kg 6770kN 5 RD-170 309s 10750kg 7257kN 5 (4.67) F-1B 270 9000kg 8000kN 5 (4.23) Merlin 282 470kg 845kN 40 (weighing about 18 tons) Ran out of rows, Raptor - 330s Unknown 1700kN 20 Again, mass reductions are possible. If we're sticking with kerolox I would go with 4 (reduced mass of everything else) RD-170 (Energia core EDIT: side engine) although if you were willing to make the fuel switch Raptor looks better due to the extra efficiency. EDIT: As far as S-IVB hydrolox engines go, there is also Vinci and KVD-1 which have higher efficiencies than RL-10 but also less thrust and more mass, so they probably aren't better. EDIT: Same thing with CE-7.5 and LE-5 for the sake of being complete.

@ProtoJeb21 The eggs, tell us about the eggs

That's the Saturn V's instrument ring, and it weighs just shy of 2 tons. Much of that is the actual ring, but many of those instruments can be made drasticly smaller, and potentially removed entirely. If we were to clear the entire ring out, make it waaay smaller, maybe small enough to fit above in the interstage (in with the LEM) then the ring can be gotten rid of, along with a few (dozen?) cm of fuel tanks across the rocket. The fins can go, too. A long time ago they studied making a second batch of Saturn V's, which would have improved something else, meaning that fins would not be needed - they were originally only there for stability in the event of a launch abort or engine out situation. They are probably at least a ton if not multiple. I cannot find concrete data on the Apollo CSM blocks, but Block II added some systems necessary for lunar operation and made some other systems lighter, so the actual mass was about the same. With modern manufacturing techniques, we could reduce the mass by probably around 10%-ish? Leading to a ~7% overall reduction in rocket size. The spacesuits are probably lighter now, too. The LEM received upgrades in efficiency to carry the rover. If we keep the changes but not the rover, the lander could be scaled back ~5% I think. Engines have come a long way, the F-1's could be replaced by either a large number of or scaled up Merlins, or Raptors if you want to change the first stage to methalox. Option 2 would allow increased S1 efficiency leading to an even smaller rocket. At least on S3, you could replace the J-2 with a few RL-10's, 50s extra efficiency (!) although you would have half the thrust for the same weight (using 5 RL-10's). You could also use improved insulation to reduce boiloff. And lastly, major tank upgrades. I have heard that the tanks as used on the F9 were way too advanced to have been built back then, so that's another couple tons off the whole rocket... Looking at payload fraction, FH has about 4.5%, the same as Saturn V, ish, despite having more tank area per volume (using 3 cores) and having lower efficiency engines, so you can probably get payload fractions up to 5-6%, which is another big chunk off the rocket, more if you switched to methalox on stage one. Short answer: estimated at 20% smaller (but if you tried really hard you could probably (?) do better.

Well, now you've got me curious, if I had time I'd try doing every single one plus a few extras, but unfortunately I"m rather short on spare time; Here is another example pulled from Google about how big these can get:

I've actually considered doing that, doing R&D and construction of Martian habitats (compact in the transfer ship, deployable, easily buildable, radiation resistant, pressure holding, modular, etc), which are something that would be needed once exploration of Mars starts. However, I have four things going against me - I don't know as much about those as I think I know, I don't have any money to start doing work, I have no idea how to manage a business in general, and I'm sixteen so nobody would take me seriously.

Cheesy sci-fi movie title: ProtoJeb The Exoplaneteer and the aliens from the planet Egg!

http://space.skyrocket.de/doc_lau/cz-11.htm Four stages of solid fuel, 2m in diameter, about 700kg to LEO, based on the DF-31. https://en.wikipedia.org/wiki/DF-31 Height of 20.8m. Those blue lines are likely-ish to be the stage lines... Either you can see the four, or the bottom two are one and there is a fourth one in the fairing. Yeah, comparatively we don't know much judged against other rockets, but hey, it's China...

It's stock, there's just a boatload of visual mods installed so it can be a bit hard to tell.

Here is a helpful tutorial: https://www.youtube.com/watch?v=vJGLAy18dBI

This is ESREP, which stands for Eve Self Refueling Exploration Plane. It has yet to actually land on Eve, unfortunately my work in this mission report save is often interrupted. However, during testing it has been shown to be capable of 100km+ hops on a single fuel tank, but slides when full of fuel due to wheel glitches. It is powered by a mammoth and two vectors and as the name implies is fully equipped for self refueling. EDIT: I have a few more planes and SSTO's for Laythe but they aren't really any different from anything you'd find on Kerbin, for most intents and purposes you can take your Kerbin planes to Laythe and they will work just fine.

I certainly do not mean to bug anyone or request a specific patch, but does anyone know if any of the releases work with 1.2.2? I would love to spice up my RSS install if possible.

Nice, are you planning to build a launch tube for Rockot?

ProtoJeb already sounds like a superhero name.

Reading the link, appears to be a suborbital liquid fueled (ethanol/LOX) sounding rocket with a payload capacity of 20kg, powered by a 12kn pressure fed engine, payload section recoverable, designed to facilitate launches within 3 months of applying. I'm reading the user's guide, I will edit this post if I find anything else of note. EDIT: They are lending out scale models, apparently. Height: 9.9m Diameter: 0.502m Wet mass: 1t Dry mass: 0.7t (wow, pretty bad mass fraction) The engine gimbals, and roll control is provided by cold gas thrusters, which may or may not be fed from the same helium that pressurizes the tanks. Maximum planned acceleration: 5g 4 minutes of microgravity, but only about 2.5 of that is very high quality microgravity. Payload must fit into a 300cm cube. About half of the cylindrical section of the rocket can be advertised on. They can mount onboard cameras. No word on price, though. I'll try my luck with their email, but the odds I'll get a response are very low.

Gah, I'm late for rehearsal because I had to watch this again.

*jaw drops* I wish I could make one rocket engine a day...