Starman4308

Looking at the atmosphere curves, SRBs are indeed a joke at Eve; their zero-thrust point is just 7 atm compared with the 12 atm of the Vector and Mammoth. The Vector and Mammoth have identical Isp curves, at 315 sec in vacuum, 295 sec at 1 atm, and 0 at 12 atm. The Aerospike shines relative to this, going from 340 to 290 at 1 atm, 230 at 5 atm (Eve surface level), 170 at 10 atm, and tailing off to 0 at 20 atm. Engines from the Eve Optimized Engines mod fare better, although they're almost horribly over-specialized for taking off in high-pressure environments.

Or mod that senselessness to oblivion! The efficiency formula is this: Eff = EB * (SBB + [SEF * EE]), where EB is EfficiencyBonus, SBB is SpecialistBaseBonus, SEF is SpecialistEfficiencyFactor, and EE is ExperienceEffect. EE ranges from 0 (no specialist), 2 (1-star engineer), to 6 (5-star engineer). So, to make ISRU be less insane, I'd tweak SpecialistBonusBase up (I have it pegged at 0.75) and SpecialistEfficiencyFactor way down (I have mine at 0.05). Alternately, set UseSpecialistBonus to false to turn that mechanic off completely. The MM patch to do it would look something like this: // Modifies the listed parts: @PART[somePart,anotherPart] { // Modifies a module named ModuleResourceHarvester // The ,* at the end says "modify all such modules, not just the first one" @MODULE[ModuleResourceHarvester],* { // Modifies the following variables to be at the set values. @SpecialistEfficiencyFactor = 0.05 @SpecialistBonusBase = 0.75 } } Otherwise: been constructing a couple large lunar stations. The propellant tank module in the foreground masses about 40 tonnes, with Real Fuels, completely empty. I finished configuring fuel cells for my installation; I independently came up with an EC-per-kilogram value that matched TaranisElsu's quite closely when I checked his water-splitter configuration, and I proceeded to nerf it; water splitting in fuel cells takes twice as much EC per kilogram water, and burning hydrogen/oxygen produces half as much EC as TaranisElsu set*. *Based on the 50% efficiency of proton-exchange membranes, though I'm not sure whether I want these fuel cells to represent a PEM cell or a SOFC (solid-oxide fuel cell). It still is by far the best option for powering my lunar ground stations overnight; 400,000 EC requires 20 tons of batteries, but I can get nearly 1,000,000 of EC for a measly 400 kg of hydrogen, oxygen, and fuel cell. I'll still probably send the nuclear reactor that I also spent a long time in Excel trying to configure; I need a surprisingly thin, 23mm lead cap for the 1.25m 300 EC/sec nuclear reactor. Thanks to all of you who helped out with info on shielding nuclear reactors; for all that I'm discovering how ridiculously effective fuel cells are, I'll still need a nuclear reactor when I send Kerbals to the outer reaches of the Ciro system. Finally, my new wallpaper from the Niven landing:

I think the point is to have it map out the surrounding terrain to help the parent rover navigate, and with how slowly unmanned rovers go, a 3-minute hop is more than enough for that purpose.

Two things: First, you're mis-reading the delta-V map a bit. On the way back from Minmus, you don't need to spend 930 m/sec again. On the way out, it's necessary to burn for 930 m/sec to turn your circular parking orbit into a highly elliptical transfer orbit; on the way back in, you can just let atmosphere brake you back down. In addition to that, the delta-V guide is a rough estimate, and it's entirely possible to get to Minmus for less. The theoretical lower bound is going to be about 4000 m/sec to Minmus and back, and you could convince me it could be practically done for around 4700 m/sec with an excellent pilot and efficient launch vehicle. Also, what Jas0n said; KER is dutifully reading the bad staging you have in the VAB and ignoring the first liquid stage (with the LV-T30 or LV-T45, not sure exactly which), because with the staging as-is, that stage is dropped the moment the engine is fired. EDIT: Also, as a side note, your vehicle has a lot of really unnecessary fuel lines and struts. At most, you need one pair of struts to secure the SRBs to the liquid core stage, the fuel lines attached to the SRB are completely unnecessary (there's no fuel to transfer!), and I'm pretty sure the fuel lines from the side tanks on the lander are unnecessary*. *At some point I should really get back to playing bone stock so I know what is and isn't still true of stock physics; I remember having to edit a line in physics.cfg to make radially attached tanks feed through.

Granted, the SLS is a mistake, but as mentioned, we can't build the Saturn V again without pouring billions into re-establishing production lines for ancient equipment. A few ideas might be reusable, like an updated F-1 engine/fuel hose instead of absurdly expensive repurposed SSMEs, but the Saturn V was a 1960s rocket with 1960s limitations, subcontractors, and assembly methods, and it would be insane to go retro when all the old infrastructure is gone. The best idea I see is to pass on the heavy lift vehicle torch to private enterprise; while lift capacities don't quite reach Senate Launch System levels, they should still fill most planned missions that aren't a waste of time and money. I'm looking at you, manned Mars missions.

There's a good chance that statement has more to do with something misheard than anything in reality. Otherwise, though, maybe they're saying that New Glenn should have more in-atmosphere maneuverability, thus they shouldn't need a retroburn to correct their reentry trajectory to land on the target barge, because New Glenn has enough control authority from control surfaces alone. I doubt that they meant anything like "we magically won't need to fire engines to kill our velocity at the end".

Column second-most to the right is where KER is printing out its delta-V estimate. It goes by stage, showing both the stage delta-V and cumulative delta-V. I'm not sure on where to set KER to show atmospheric delta-V*, but there's probably a toggle somewhere. *Being in atmosphere means that your engines produce less thrust, and since you're still consuming the same amount of propellant, your Isp is dropping by the same factor. Very loosely, you can think of it as atmosphere pushing back on your exhaust gases. First stage type engines like the LV-T45 and Mainsail trade off some vacuum Isp to improve their sea-level thrust/Isp. Overall, it looks like you might not know what delta-V is, which is a very important concept. Delta-V is essentially your ability to use engines to change your current velocity, and is determined by how much fuel you have and how efficient your engines are. You use delta-V to execute maneuvers; if you have no delta-V (no fuel) remaining, you're at the mercy of gravity, atmospheres, and lithospheres. In the absence of gravity: if you are traveling 2000 m/sec to the right, and have 1000 m/sec of delta-V, you can use that 1000 m/sec to: Burn prograde and hit 3000 m/sec right Burn retrograde and hit 1000 m/sec right Burn perpendicular to that vector and achieve a velocity of 2,236 m/sec (2000 m/sec component in the original vector, 1000 m/sec component perpendicular) Delta-V can be calculated manually using the famous Tsiolkovsky Rocket Equation: dV = Ve * ln(mass of full stage / mass of empty stage). dV is your delta-V, Ve is your exhaust velocity, ln is the natural logarithm, and it's important to remember that mass of the empty stage is not just payload, but also empty fuel tanks, engines, etc. Anything that isn't fuel. Now, you may ask yourself, "where is that specific impulse everybody talks about?". That is in the Ve term. Specific impulse is equal to exhaust velocity divided by 9.8063 m/sec^2 (surface gravitational acceleration on Earth/Kerbin). As such, the Tsiolkovsky equation is often rewritten as: dV = Gm * Isp * ln(full / empty) That raises the question of why we use something so silly as Isp instead of just listing exhaust velocity. You can thank me and my fellow Yanks for still not switching over to MKS. You see, early in rocketry, people in the US were using ft/sec for exhaust velocity, while everybody whose nations had converted to sane units was using m/sec. To make things simpler, they just decided to divide by the surface gravity of Earth (9.8 m/sec^2, 32 ft/sec^2), getting a measurement that depended only on the unit of time, and at the end, they would just multiply back by that gravity to get exhaust velocity back. The final major thing to note is what the equation looks like when you flip it around, set a desired delta-V target and ask "how much fuel do I need relative to the empty mass". full/empty = e^(dV / Isp * Gm) You'll notice that's exponential, the tyranny of the rocket equation. For large delta-V, Isp becomes hugely important, because you get to divide dV by Isp before taking that exponent. It also imposes some fundamental constraints and requires staging: for stock (where a full fuel tank is 9x heavier than when empty), the absolute maximum you can get out of an engine without staging is Gm * Isp * ln(9).

Large scientific probes, space tourism, and space station construction & resupply come to mind. I'm skeptical that super-heavies will start to become very common, but with the recent drop in cost, I suspect demand will go up a bit. One thing I suspect will help is that a lot of the recent heavy-lift vehicles and proposed vehicles are based on lighter-weight vehicles with higher operational tempos; Falcon Heavy and Delta IV Heavy are basically three lighter LVs bolted together, I think there's a similar proposal with ULA's new Vulcan booster, the Atlas (and Vulcan) can use a variable number of SRBs, etc.

60 km per sec is quite steep. The Galileo probe hit Jupiter at a mere 48 km/sec, and would have liquefied any human onboard. From what I've gathered, ordinary LEO rated shields would have just exploded on contact, and I'm not sure any RO part would've sufficed, nevermind liquidating the Kerbal cargo.

Glad to hear it. I'll probably be tinkering with the life support configs soon; I pretty much completely forgot about the existence of fuel cells, so if I mod those to use hydrogen+oxygen instead of LF+O as resources, crack the output water back to hydrogen+oxygen during the day, and either mine hydrates or send water to replace what the astronauts went through for life support, I have a second backup system in addition to the nuclear reactors I'll be sending. Also, "you are only allowed to give 25 likes each day". I visited the SpaceX thread.

Thanks for the link; I really had thought hydrazine would be too toxic to muck about with for a cubesat. Maybe then, they ship you just the empty propulsion system, and you pay the payload integration team to fill up the hydrazine tank before putting it on the launch vehicle?

Depends how much delta-V you have. The cheapest option is a bielliptic transfer; at periapsis, burn until apoapsis is nearly at the SOI edge. At apoapsis, flip your orbit, then burn back down at periapsis. The slower you go, the easier it is to change direction, and for large plane changes (of > about 85°), it's cheaper to push apoapsis to near escape velocity and back again than try to make your plane change immediately.

I know it's been a while, but I have an excuse. The cable repairman held up a severed piece of cabling, as an Aztec priest might hold up the still-beating heart of one of his victims, a tribute to our collective masters. As he chanted the divine words and made the sacred motions to patch a line to my apartment from the main box, the heavens themselves quivered, and then stilled, as once more gigabytes of inane arguments, memes, and silly cat videos flowed through. Augustus Servicing Mission 1: Partial Success The first mission to service the Augustus telescope was a partial success. While the optics and gyroscope were replaced, the crew failed to add a docking port, as the servicing vehicle, clumsy with the transfer stage still attached, drifted too far away from the Augustus telescope while operations were in progress. Project LTHab: These Stations are Fully Supplied and Operational The lunar space stations have been fully assembled. In addition to the core and ELSIE modules, a pair of standard lunar landers have been docked, as well as the enormous propellant supply depot, affectionately named the "cat-tail" for its appearance when still attached to the booster. While sent completely empty, it should be possible to fill the hydrogen and oxygen tanks with surface hydrate mining operations, send hypergolic propellants from Gael, and manufacture a small amount of methane from the onboard Sabatier reactor as a byproduct of recycling carbon dioxide to oxygen. Unmanned Niven Landing A lightweight lander has been successfully deployed to Niven, making crucial measurements of atmospheric and surface conditions. As is the standard for landings on worlds with poorly measured atmospheres, the Niven lander used a combination of a heat shield, hypergolic engine optimized for sea-level operation, and a parachute. In surveying the surface around the landing site, Icarus was spotted just over Ciro. Key to future exploration is the detailed measurements of the Niven atmosphere on descent; it's Karman line appears at 91 km, and at the landing site, atmospheric pressure was 0.083 atm. The relatively thin but deep Nivenian atmosphere suggests the possibility of aerobraking; while velocities are high enough that any probes must have thermal shielding, it could save significant amounts of mass in propellant and engines, particularly for lander missions that would use a heat shield in any event. Project HIGGS: High Impulse Gas Giant Survey The HIGGS project has two aims: first, to characterize the two inner gas giants, Otho and Gauss, and two, as a technical demonstration of nuclear power and propulsion for high-impulse missions. No less then three technologies are being field-tested for the first time: cryogenic ZBO (Zero Boil-Off) tanks with active radiators, nuclear-thermal engines, and radioisotope thermal generators for power. While Otho could be reached solely on the launch vehicle, with all of the liquid methane working fluid for the "Shiba" engine reserved for deep-space and near-Otho maneuvers, the Gauss mission required the use of the Shiba for the last few hundred meters per second. While an interesting trajectory that would brake around Catullus twice was investigated, eventually mission designers decided against entering to a retrograde orbit: the final trajectory will pass by Catullus once on the way in, perform a relatively small propulsive maneuver at perigauss, and begin science operations. Geminus Lander A lander festooned with solar panels for operation at Gratian's distant orbit landed successfully at Geminus, inserting directly into Geminus orbit instead of first capturing at Gratian. Vehicle Design Notes Not in-character as the Gael Space Program, just noticing a few design patterns I've used. First, a couple missions to the Gratian system have used a Gigantor solar panel on one side of the service module to approximately counter-balance the main communication dish, which becomes superfluous once in range of the Gratian relays. You can see it on the Geminus lander before the service module is discarded. Second, you may notice a lack of failures for the most part. There's been a few cases where I've had to revert-to-launch because I forgot some silly part, or the staging was messed up, or I forgot to lock the gigantic empty fuel tank and the launch clamps filled it up, or I forgot to change the RCS ports from using hydrazine to the bipropellant used by the main engine, but rarely do I have a failure beyond launch. Part of it may be simple, self-contained unmanned missions, and another part may ironically be all the things that TAC LS, Remote Tech, and Real Fuels force you to consider. You have to consider which antenna, so you have to consider your power supply, etc. Generally speaking, my failures end with a facepalm, revert-to-launch, and a whimper, not with an earth-shattering kaboom. Third, I've noticed my recent crop of landers for atmospheric planets could use additional capacitors to help power science transmission from their atmospheres; the stock atmosphere sensor, in particular, goes through EC at a ridiculous rate, meaning I can't extract all the science I want. It can also mean very long recharge periods to finish transmitting surface science. In the case of the Gratian lander I'll talk about next time, very long recharge periods. Finally, no, I did not notice that the lunar propellant supply depot modules looked like giant cat-tails until after they launched.

A pack of Zachtronics games are on sale, games like Shenzhen I/O. I figure this forum will be enriched for those who would find a game about assembling microcontrollers fun. Scott Manley has a video series about Shenzhen I/O here (and yes, that's how I know about the game): If you want a taste of what Zachtronics games are like, there's a few of them free online; I'm pretty sure I know more about the low-level engineering of computers thanks to "Engineer of the People".

If you have a high level engineer aboard and are careful not to stray too far from ore concentrations, you can also use ISRU to generate more fuel than it takes to power the drills and ISRU unit. Completely unrealistic, but it's hardly the only absurdity. What is surprisingly realistic is that 0.625m nuclear reactor from USI; it's not that much lighter than actual reactors sent to space. I still prefer the Near Future aesthetics, but the lightest NF reactor is about 0.33 tons.

To be fair, it does add a bit of operational flexibility; if, say, you eject the pod from the service module and want to tweak your reentry a bit, it's nice to have that RCS available. It's why I often slap a couple of the linear RCS ports onto Mk 1 pods and a ring of quad-ports onto larger capsules. I will, however, grant that with many types of staging design, it probably overall reduces available delta-V; it just adds a bit of delta-V that isn't gone even after service module separation. Part of what ameliorates things for me is that Real Fuels drops the mass of the parts significantly (11 kg for the linear ports, 15 kg for the extra-light quad blocks added by KW Rocketry), so there's less lost by adding the RCS ports. It doesn't help with the heavy, low-Isp hydrazine, but it's a tradeoff I'm willing to make for a small amount of last-second maneuverability.

I do it so I can let MechJeb (or a kOS script I wrote) handle the burn. Routine burns like circularization at apoapsis are utterly uninteresting to me, so I just let an autopilot handle that for me.

It's a pretty dang impressive mission, that's for sure. As I understand, the three LISA satellites will be using tiny thrusters to keep station with test masses contained within a vacuum inside them; the outer satellite shields the inner from any non-gravitational forces, and uses minute thrusts to keep station and make sure they don't bang into those test masses. All so that they can serve as multi-million-kilometer detector arms for a laser interferometry experiment to detect gravitational waves.

It continues to amaze me how much scientific equipment can be carried onboard such a tiny little satellite. I'd be curious to know when you expect the tether's electrostatic drag force to be exceeded by atmospheric drag in de-orbiting Aalto-1. I suppose one major advantage of the electrostatic tether method of de-orbiting is that you don't need to carry any sort of propellant; the usual suspects for small motors (hydrazine, hydrogen peroxide) are right out due to either being unstable or hilariously toxic. I suppose a cold-gas thruster might work, but you typically need a pretty heavy pressure vessel to contain that, and overall it just seems like an electrostatic tether is a far better option for nanosatellites unable to carry their own propulsion.

In my experience, roughly on par with each other, though I prefer the aesthetics of the NF reactors. Don't forget the NF reactors have an optional top node that can be activated from the part menu.

What you presented is extrapolation, not necessarily sound logic. The takedown of OpenIV was done because it allowed cracking into protected assets. This does not imply they are evil and hate fun or creativity. It implies they care more about maintaining their EULA and business strategy than about mods. They are almost certainly indifferent, not evil. For KSP, attempting to crack down on mods would be a disaster. Numerous copies of DRM-free KSP exist, and given the much higher fraction of PC players, more of their customer base would raise a fuss. Furthermore, it would anger the primary development team, who can perfectly well quit and denounce Take Two at the expiration of their current contract. Nor do mods threaten their likely business model as did OpenIV. It would be far too much hassle to add DRM or microtransactions after the fact; I doubt they'd bother. And now most of what I'm saying was said better by @Snark. I blame typing on a mobile tablet.

Sources please! No, seriously, a few GTA mods getting taken down doesn't even imply GTA modding will disappear, nevermind KSP mods.

It completely depends on which direction you enter and exit the SOI. That is the whole point of gravity assists: you have the same Eve-relative velocity going in and out, just in different directions. When you enter Eve SOI, your Sun-relative velocity vector is Eve's velocity vector, plus your Eve-relative velocity vector. When you exit, your Sun-relative velocity vector is Eve's velocity vector, plus a new Eve-relative velocity vector of the same magnitude but different direction. So, if you're using Eve to brake into Moho, what you want to do: Enter Eve's SOI from behind Eve, go around the front side, and go back out from behind Eve. Let's say you have an Eve-relative velocity of 2 km/sec, and the gravity assist does a perfect U-turn. Eve orbits at roughly 11 km/sec. So, before the intercept, you have 13 km/sec of velocity relative to the Sun. After Eve turns you around, you now have 9 km/sec of velocity relative to the Sun. In practice, you're not going to get perfect U-turns, but the theory remains the same: speedy thing goes in, speedy thing comes out, but in a different direction.

We have a full-fledged space simulator with a large, varied solar system and numerous modes of exploring that, plus a wide variety of mechanics such as CommNet, full treatment of thermal effects (reentry heating, insolation, etc), space center upgradeability and destructability, and ISRU to flesh things out. Do not confuse "I want this thing" with "this is necessary for it to be considered a full video game", particularly when it's been primarily developed by an indie studio who had to do a lot of behind-the-scenes work to make it function. Krakensbane, writing a patched-conics solver, thermal treatment, non-souposphere aerodynamics, all of these are non-trivial projects that aren't flashy but make the game what it is today. Squad is a business, not a charity. As it is, they have been remarkably patient and helpful, doing things like giving out free DLCs after a mistake in the wording of their EULA, ensuring much of the code is made public for modder accessibility, etc. I see so much vitriol spewed about the Unity engine, and I've yet to see convincing evidence that other engines would even do a hugely better job of dealing with rigid-body dynamics on hugely interconnected vessels. The GC issue might go away, but that would be its own nightmare trying to chase down every possible source of a memory leak. In general, switching engines would basically entail rewriting the entire game. It is simply economically infeasible. KSP is perfectly playable after version updates... unless you mod the game, in which case you should learn to be patient and wait for mods to update while continuing to play the old version. You mod at your own risk. EDIT: It was brought to my attention that at least a small subset of players do have issues with updates even bone-stock. I wish the best of luck to those people; sometimes you get some strange things happening. Um, you do remember that Take Two has Squad on contract for development, and better sales of the DLC give Squad more leverage to bargain for a higher-paying contract, right?

Augustus linked a technical document in this thread: Overall, I am hugely in favor of the idea; it's past time we studied the ice giants in detail, and I think a big, flagship probe mission to planets we've never orbited before is the perfect way for NASA to point out that their mission continues to be relevant and that NASA still has purpose, even when certain Senators decide that they'd like NASA to be a jobs program for them. While I don't have RSS installed... I might try a similar mission profile in my own career; drop a probe at Nero using a parent orbiter as relay.