DerekL1963

Ahh... the sunk cost fallacy rears it's ugly head once again. Alongside the broken window fallacy... Only if you reduce the size of your payload. Which just brings you back to the same starting point.

No idea honestly.

We got bored one patrol and started thinking about exactly what would be required to convert the 'Hog* into a spaceship - and found something surprising (though it shouldn't have been in retrospect): The reactor** (and pretty much all of the rest of the important and desirable machinery onboard) absolutely depends on the presence of gravity to operate correctly. To convert her into a spaceship would require significant engineering and rebuilding. * SSBN-655 - the USS Henry L. Stimson, known to her crew (for reasons lost in the mists of time) as the Henry Hogbody or simply the Hog. ** Because of the pressurizer.

True - but it does allow you to take advantage of the trade secrets laws. The big downside there however is that (unlike patents) if someone indepently comes up with the same ideas, you have no legal recourse. That being said, SpaceX's secret sauce almost certainly isn't technology, but implementation details... Which are not impossible to reverse engineer. I know at least two people, one of whom is writing flight code for a rocket business you'd recognize*, who could create and implement the requisite algorithms and control laws. (Implying that if I know two, there's probably hundreds or thousands in reality.) The same thing for the engines and the related valves, rocket plumbers aren't exactly rare (I know several). Etc... etc... Propulsive rocket landings aren't new after all. Nor is hovering under rocket thrust. Amateurs have done both. Though they (briefly) used a parachute for stabilization, Armadillo Aerospace demonstrated the basic concepts six years ago - and the idea wasn't new then. (ISTR Armadillo demonstrating the same basic idea, absent the shutdown of the motor, circa 2004.) SpaceX's big secret could very well be that there isn't a secret. * For reasons, I cannot divulge who or for who. Sorry.

In terms of nuclear weapons fizzle means nothing more than failing to reach the designed yield, regardless of the cause (and there are numerous possible causes). With a yield of 110kt, Castle Koon is still considered a fizzle because it was expected to have a 1 megaton yield. (The primary fired at full strength, but due to a design flaw the secondary failed to properly ignite.) The Castle test series was something of a mess, with not only the largest fizzle ever - but multiple devices that exceeded their planned yields (including the infamous Castle Bravo).

5 launches/yr at the beginning (426/5=85 days between launches), increasing every 3rd year until I hit 10 launches/yr. Slow at the start, then ramping up as my simulated infrastructure is built out. As always, YMMV.

Though my cadence is slower, this is exactly what I do - set up a repeating alarm.

Since you're reporting in progress - I'd say "Mission Reports".

One common mistake I see even experienced players make... they start with a vehicle that's too big and keep making it bigger to attempt to overcome the inevitable problems, which actually ends up making things worse.

Ah, that happens. I'm with you on simple, robust, and "good enough". But what constitutes "good enough" also depends on what's acceptable to the relevant regulatory bodies. We're not going to orbit from any first world country without a launch license. Though if you have an inertial system... why do you need a sun tracker in the first place? An amatuer effort is generally stuck in a strange place... Not enough money for pro gear, but often also not enough money for a R&D program to develop a suitable replacement on a reasonable timeline. And almost never enough for "innovation".

Accurate to arc minute tolerances and capable of withstanding the vibration and acceleration of a launch with an acceptable (.95+ at a minimum) degree of reliability? Just because the concept is simple, that doesn't mean the design and execution is equally simple. The algorithms and the math are the easy parts. The hardware is the hard part. The hardware is almost always the hard part.

Certainly. Minmus and beyond.

That's a pretty sophisticated system - and it may lock you into a single payload and a dead end program. That's certainly a valid choice, but one that should be made deliberately rather than bumping into it by accident.

Seems to me you could put the guidance on the second stage. That way you could either get better performance out of the third, or for the same payload reduce the weight of the third to increase the performance of the overall vehicle.

True. Space Planes can be excused under the Rule Of Cool if nothing else. But the questioner is new and maybe unaware of the nature of his full range of options, so I wanted to make sure they were clear.

Meant to comment on this earlier. While there's no overwhelming reason not to use a space plane (though the thin atmospheres on Duna and Laythe raise the difficulty), there's no engineering reason why you have to. Both of them can easily be tackled with an ordinary ballistic lander.

I'd say that you should, as stueben recommends, head over the Challenges subform and dig into the Grand Tour challenge. (The Grand Tour is pretty much what you're proposing.) If you want to scale back the challenge (moderately, from "almost impossibly difficult" to "insanely difficult") you can also dig into the Jool-5 challenge. You can also start with your own mini-challenge by doing this first with the Mun and Minmus to get a feel for the problem.

That doesn't make what Nibb said wrong. That increase in first stage mass is cheap - it's all tankage and fuel. (And setting aside that the mass savings from a smaller first stage are partially offset by the mass increases in all stages to allow for horizontal carry and to withstand the stresses of the drop.) But this discussion isn't just about the physics. It's also about the costs, particularly the elephant in the room - the launching aircraft. (Estimated at $300 million six years ago for Stratolaunch, almost certainly much higher than that in reality.) That's long been the basic economic problem for air launch systems, the economics only make sense if you're launching a significant number of payloads. Otherwise, you end up with Pegasus, one of the more expensive civilian launchers rather than being one of the cheapest. (Another part of this is because air launch doesn't save any man hours in the launch campaign, in fact it adds to them.)

Since I didn't question either how easily either could be done, or claimed some other solution would be able to start producing so easily, I completely fail to see your point. No offense, but while you quoted what I wrote - but did you actually read it? You're the one that introduced costs and used them to dismiss solutions other than your preferred one - while not actually producing any cost estimates for your preferred solutions. You cannot have it both ways. You can't claim your solution is cheaper - and then fail to justify that conclusion. Since you made no technological or mathematical comparisons... You just rejected other solutions and went into deep detail on your preferred solution. Again, what you claim to want to do and what you actually do are at odds.

The trick is to jettison in the right direction... retrograde in the first instance, normal or anti-normal in the second.

Not really, no. Lunar mining (for example) is dismissed in a few lines as being "too expensive". Boosting from Earth is equally curtly dismissed ("requires too big [expensive] of a rocket"). Comparisons of technology are noticeable by their absence. Yet, you dismiss all technologies that aren't your favored solution as "too expensive" without providing any justification for the claim. You can't have it both ways. You can't claim to be comparing the "objective" merits of various technologies when you only discuss one technology. You can't bring in costs for solutions that aren't your favored one and then dodge the question of the costs of that solution. (And your readers in this case are the denizens of the KSP Science & Spaceflight sub-forum. We're interested in the details, not so much in high level handwaving.)

o.0 I've read that half a dozen times, and I still can't parse it. If you're not comparing the costs (which you brought into the discussion), then what exactly are you comparing?

On orbit refueling always comes out looking cheaper because the cost of the propellants delivered on-orbit is basically handwaved away. This article? Really no different - while is waxes scornfully on the cost of launching into orbit, it doesn't once touch on the costs of developing, building out, or operating and maintaining the system.

Wouldn't even know how to do it honestly...

I'm working on this little beast and have encountered an oddity with the helicopter controls: They'll let me tilt the rotors forward and gain speed - but not backwards to put the brakes on.