MarvinKitFox

True, atmosphere tends to have too low density. Oceans though.... ripe for the "burning" All you need to do is pump in a bunch of muons. If you have a sea of "heavy water".. i.e. deuterium replacing a significant part of the hydrogen, then a single muon will trigger several *hundred* D-D fusions before expiring. But no natural planet has that high a percentage of Deuterium. However, if you put in enough muons, so that you get a significant percentage of H-H collisions where *both* of the H are under the influence of a muon at that time, then you get fusion at dang nearly any temperature. Even down to deeep cryo temperatures! So, simply pump in enough muons into a water ocean to replace 1/1000 of a percent of the electrons in that volume with muons, and the whole thing will fuse. First the H-H will fuse at room temperature, heating the whole ocean up to the low millions of Kelvin, then at those temperatures you will see muon-catalysed fusion of Carbon, Oxygen, possibly even Nitrogen. Do this to just a 5km sphere of ocean water, and you have the needed 2e32J explosion to rupture the planet! (Ok, so you still need to be able to generate several **kilograms** of Muons, and send them off to your target at high relativistic speeds (needed to keep them fresh, Muons have a short half-life), but that is still very much easier than having to supply the needed 2e32Joules of energy yourself, whether as energy in photons, or 60 billion tons of antimatter, or whatever...)

Once a reactor is shut down, the problem is greatly simplified. A shutdown, intact reactor is only really dangerous as a gamma source. And that gamma flux is 10^6 or more weaker than the operating levels. Remember that, as a rough rule of thumb, each 1mm of lead shielding will halve the gamma passing through it. (varies by gamma energy, of course) A ship could park a few tens of meters away, and its normal shielding against space radiation will keep it safe. The nuclear rocket itself will almost ignore the residual radiation, as it already has shielding to handle millions of times that output. Maintenance becomes problematical, of course. The reactor core and casing will become so radioactive as to quite preclude on-site work by human or electronic-operated tools. You would need to use long, mechanical devises, etc... Better design it to never need maintenance. In most cases, reactor radioactivity is only a problem when there is a possibility of some actual material passing from it to the environment. The nuclear thermal reactor is almost the exception to this rule, as under operation it output ludicrous amounts of radiation, *and* one simply cannot afford to encase the core in a thousandth of the shielding you would normally want to, due to mass/weight restrictions.

Right there is all the heat shield you will need. Re-enter, put your perigee at about 40km. Fly backasswards. Your engine is quite capable of absorbing this level of heat. Shtuff that is mounted towards the outside of your rocket may tend to explode off, just bear with it. Keep your orientation as engine first, rocket body a bit closer to horizon than flight path, so you get a decent lift element without incurring max heat on the weaker parts.

Hydrogen does permeate through most materials, but for more-or-less unpressurised LH2 the amount is utterly negligible as to loss of fuel. You do need to worry about just what all the hydrogen is doing to your fittings (embrittlement, etc..) but simple thermal boiloff is a cause of fuel loss several magnitudes bigger than permeability losses. Just keep your fuel rods well separated, and keep them away from the delicates. Silicon and carbon-based lifeforms (computers and Kerbals) seem to be allergic to the effects of too much radiation.

Nerva technical docs: http://fas.org/nuke/space/nerva-spec.pdf the more relevant bits are around page 64 Some info derived from: http://www.calculator.org/property.aspx?name=radioactive%20dose%20equivalent https://www.osha.gov/SLTC/radiationionizing/introtoionizing/ionizinghandout.html http://www.kayelaby.npl.co.uk/atomic_and_nuclear_physics/4_7/4_7_3.html Power levels: The radiation output scales almost linear with reactor power output. Nerva was designed around a 4Gw reactor, final plans were for a 7.5-8Gw design. Yes, Hydrogen is an **excellent** shield against neutron radiation, especially as only a miniscule amount of it will get changed into anything radioactive. H->Deuterium->Tritium is needed, very unlikely. Tank heating is a factor you will have to work around, but it is by no means unsolvable. In space, if there are no friendlies within several kilometers to the side or rear, a nuclear thermal can be made quite safe to operate without needing any explicit shielding. Just put your H2 fuel tank in front of the reactor core, then your water+foodstuffs+inert supplies, *then* your delicate crew and electronics. The Aerojet Nerva spec allows for shielding sufficient to limit crew exposure to under 10 rem per hour of thrust. Where a Nerva-style nuclear thermal is dangerous is when operating under full thrust, and for anyone/anything that is near it in a direction where you can not afford to slap in several tons of shielding. Such as to the rear!

Using a nuclear thermal rocket in the earth's atmosphere is quite insane, as: 1) if anything, but *anything* goes wrong, it can spew its guts all over the landscape. This is the very definition of Bad. 2) Backscatter from the surrounding atmosphere would require shielding in all direction for any crew or electronics on board. Using a nuclear thermal rocket in space has great potential, although still a bit risky. 1) The radiation flux around your motor is intense* . You need to be several hundred meters away, or you need to impose many tons of radiation barrier between the engine core and anything delicate. (like pilots, electronics, plastics, steel girders, etc) Yes, i said steel girders!! Just what do you think happens to a steel beam exposed to a longduration intense neutron flux? 2) If it blows up, and *any* of the core debris could hit earth at any time in the next several millennia, you will have a bad day. This kinda means you need to operate the thing only outside of Earth's gravitational influence, **including** any earth-orbit-crossing orbit track! Note that an unfired Nerva-class motor is reasonably benign, you have neatly packaged fuel that can even be in a reentry-safe housing. The danger is that after your motor has operated for several minutes, the whole motor + casing + superstructure becomes intensely radioactive due to the ludicrous unshielded neutron flux that is a basic part of the operation of this sort of motor. Definition of "Intense" as used here: At full operating thrust, the engine emits a fast neutron flux of about 2 * 10^14 neutrons per square cm per second, at a distance of 3 meters outside the unshielded motor casing. Even ignoring the gamma flux, this is a 100% lethal dose of neutrons in 1/8600 of a second!!!!!!!!! Or a lethal dose in ONE SECOND at a range of 300m

I believe the poster's problem is that his rocket is staying above the 260m/s max speed allowed for parachutes, even when in freefall near the surface. Advice: 1) land in the ocean, or at highest shore/grassland/ice regions. The altitude of any other terrain leads to too-thin air for speed reduction by drag alone. 2) Use a much more draggy vehicle for reentry. A naked MK1 capsule is draggy enough. The same capsule with 17 batteries, 8 instruments and a partridge in a pear tree is simply too heavy! If you have a lengthy vehicle, try forcing it to go sideways during the last freefall. If you have landing gear, deploy them. Try to induce a rapid spin/flutter in your descending vehicle. This may *look* uncomfortable, but sure induces a lot of drag! 3) Consider re-entry with a functional engine, and flying engine first. The engines are almost as heat-resistant as an ablative heatshield, plus you have the ability to use thrust to brake you below that critical 260m/s limit. Also, with use of a bit of thrust AT landing, you can afford to load *way* less parachutes. 4) Once you get them, drogue parachutes allow deployment at much higher speed and altitudes, and Airbrakes even more so! Have fun!

To answer these in sequence: *As has your posting. *Yes. 5 minutes of googling brings up 3 separate references to exactly this. Just because you cannot conceive it, does not make it inconceivable. *You have a low boredom threshold, and a very pessimistic outlook on life. *You have a low boredom threshold. This is usually caused by a low imagination activation. Stop finding fault with the world, and start finding the FUN in the world. KSP is a GAME! You are supposed to be having fun. It is a wide-open universe full of rich opportunities, new discoveries, and daunting challenges. But in the end, it is up to you to *decide* to enjoy it.

I do something like this, but only for the first 100m/s or so. That engine loses a lot of ISP in the thicker air, and crowding mach-1 while in the lower atmo is just counter-productive. That said though, I do not see how they manage such high efficiency. I can trivially get 146LF left, but even with 10 retries I never exceed 150. Now if only I was allowed to sell off that unusable Monopropellant, the unneeded fins, and the surplus oxidizer. Ah well! No official entry until I figure something better.

New-ish game, 1.0.5. Mods alarmclock, KER. Nothing that should change gameplay. Jeb is piloting a very basic airplane, that is taxiing around the KSC base. Problem is, it allowed me to quicksave while still on the ground, and rolling at some 35m/s (well below flying speed). As I then exited the game to try figure it out, his death is saved in persistent. When this save is loaded, the whole plane instantaneously explodes! Log says multiple collisions with terrain. Visual shown plane falling *below* surface by about 2m, then shredding. Looking at the .sfs file, it shows state as "flying". Ok, so thats why it allowed the save. But on load, he falls through the ground before the wheels realize that they should support the plane's weight. How do I fix this? Preferably without editing the save file, but that will do in a pinch. How do I avoid it in the first place? Didn't the game use to refuse a save while on the ground, or with collision very imminent?

Fortunately, these would be designed by someone that has a clue what he is doing, not you or Newton. Newton's law does dictate that the *momentum* resulting from an explosion would have to be symmetrical , but there is no such limitation to the *energy* distribution.

Back in the days I did this: This adventure ends with a non-parachute, non-wing landing, falling from Eeloo, "landing" in KSC just near the launchpad. Landing speed 134m/s Damage to Kerbal: nil Damage to spacecraft: one of 8 arms broke off.

When you overhang the launchpad.. On ALL sides at the same time! Or when you build a Futball stadium on top?

Poor Eduard, aboard Helios III He was swinging a safe (he thought) distance past the Sun, doing science-y stuff in a low solar flyby before returning home. Apparently he miscalculated the solar heating flux. First to blow was the nuclear engine. Then, as the heat slowly crept up, he started losing instruments to apparently random thermal explosions. Not all at once though! Only about one part blowing up per 5 minutes, as the solar heat slowly cooked his ship. booom. This is Eduard, aboard Helios III. Can anyone hear me? overheating. The Sun is cooking my ship! there goes the Goo experiment . . . booom.. solar panel #3 . . . . bam bam booom... that sounded like a cargo bay, and the RCS fuel units. . . . wham.. just the capsule left, maybe if i orient it so the heatshield faces the sun? . . . . boom boom WHA......signal lost.

For purpose of ENTERING a SOI the radius is a teensy bit less than for purpose of EXITING the same SOI. A difference of a few tens of meters If you are skimming part a planet's SOI, you will either hit the SOI and stay in it for several minutes, or miss it altogether. It will *never* flick you in and out in a small few seconds. (tested with a 10-ton ship, burning a single ion drive for as short a duration as I could manually manage, when 10 minutes from SOI entry. The displayed velocity did not change even in the 0.01 digit on KER's display.

Well, this little adventure in my youth did come close to it...

My compromise for this situation: I have disallowed revert, quicksave, quickload etc... BUT, I do allow manual save (not load) at the Space Centre screen. If i then encounter a situation where loading is *really* needed, I can. Simply close the game, locate the savefile.sfs and rename it to persistent.sfs reload the game. This allows disaster recovery, but only at the expense of some very significant personal effort required. I.e. not to be used frivolously but still available for when the fit hits that shan.

I hope the loading time is just teething problems? Waiting 10-15 seconds between pages is a bit tedious.

[quote name='SlabGizor117']I agree that this will help but I promise the joints between those parts are ridiculously unstable and [COLOR="#FF0000"]I know that's the main problem[/COLOR]. KJR won't completely eliminate that problem though.. Will it?[/QUOTE] I've highlighted your mistake for you. The problem is not weak rocket body, the problem is excessive applied bending forces. Fix the way you design and fly the rocket, and you will find that the rockets are miraculously "stronger"

The only change? You also changed from KSP beta 0.25 to Kerbal Space Program 1.0.x, which in terms of aerodynamics is as big a change as going from Wright Brothers Flier to Spitfire, and expecting similar flight behaviour.

The most *correct* measurement is relative to the stationary point that is the center of the current SOI. This is not the most convenient!

If you can cook one meal in one hour in a kitchen with one stove, how many meals can you cook if you cram 73 stoves in there? *not* 73 Your constraints for mining are 1) electricity and 2) temperature. By adding a mountain of extra heat generators without increasing your heat removal at all, you have merely ensured that you are overheating all the quicker.

And right there you show that you do not have the faintest clue what forces are involved. You need to sit back, throw away old preconceptions, and think about what forces are involved in aero. Hint: Go skinny, not squat. Yes, bigger turning forces on a long vehicle, but also much greater turning moment. Allows you to react in much slower time. Go Nose-heavy, not tail heavy. You want drag to pull you straight, not push you off-prograde. Aim very very close to your *surface* prograde vector. I.e. start turning very early, and turn very slowly. Not so early that gravity-induced sideslip becomes a problem though. Steerable engines are awesome for control, rather than extra RCS, for when you get into the high atmosphere.

Dres: A minimalist technique whereby a vast void of emptiness is made to appear even larger by inserting a single speck within the void, thereby accentuating the utter uselessness of the region. example: The famous "loneliness" by Vadim Skapenko

1) put wheels on straight 2) put wheels on solid 3) less weight per wheel 4) Center of mass must be *just* forward of the rear wheels.