sevenperforce

As would I, but you're much more likely to gain critical acclaim in a stone age society through the avenue of astrology (simply because you'll be able to accurately predict star alignments, planetary conjunctions, etc.) than through astronomy, which wouldn't yet exist. Yeah, this is a big element. Which is why I think that what you encode has to be BIG. If it's big and everyone knows it's been there for thousands of years, it's obviously not fake. How would you signify E = energy, M = mass, C = the speed of light, and n2 means exponentiation? For that matter, how do you signify that "=" means "equals" or that mushing two things together means multiplication? Also, "9.81" is not meaningful unless you can also define meters and seconds. (not to nitpick; this is just a question I've thought about for a while so I'm curious to see what people come up with)

Here's a thought experiment. Imagine you suddenly found yourself transported back in time thousands of years, to an arbitrary stone age or early bronze age civilization (dynastic Egypt, ancient Mesopotamia, druidic Britain, etc.). Fortunately, you quickly learn the language and culture, and in true Connecticut Yankee style you make your ascent to a position of power within the society. You cannot, of course, manage to effect full industrialization since that infrastructure would take a few hundred years to get up and running, but you make enough contributions to agriculture and astrology and military tech that you're sure to be remembered as a great leader. It's at this point that a thought occurs to you...what if you could be remembered as more than a great leader? By now, you've already reached the conclusion that the future you remember is gone forever. You've already changed history enough to ensure that. But you can guess that thousands of years in the future, archaeologists will dig up your civilization, and you want to give them something to really blow their minds. What do you do? You can write down your story -- "I'm a time traveler who came back from the year 2018 and used my knowledge to become powerful" -- but that's hit or miss. For one thing, you can't write in English, because English probably won't evolve in the same way, and if you write in the language of your civilization then you're more likely to create a new religion than anything else. Plus, written texts don't really survive very long, and in any case you can't make predictions about the future, because you don't know the future any more. You do, however, know that certain things don't change. Like the value of pi or the mass of an electron or the speed of light. How would you encode advanced scientific knowledge in monuments or other relics to give future archaeologists the shock of their lives? My own idea, spoiler'd:

Exactly.

I once played around at great length with a gyrojet-styled bullet. Differences were ring fin stabilization in place of spin-stabilization, a pressure-bearing (albeit short) barrel to fix the low muzzle velocity, and caseless propellant. Would have had ridiculously good performance. Would also have been ridiculously expensive.

That's terminal velocity. Because the scale height of Kerbin is so low, air density increases pretty consistently as you drop below 10 km and so terminal velocity will drop as well. But it's a pretty narrow window.

Yep.

I did single-seat cockpit + Twin Boar and managed to get into a 69,000 x 67,000 m suborbital orbit with fuel remaining. Will take quite a while to decay. I may need to set the ceiling at something like 45 kilometers so that there will always be enough drag to bring you down in one go-round.

Critical: George Nield, another ASAP member and former associate administrator for commercial space transportation at the Federal Aviation Administration, recommended NASA look at overall safety, not just of crews on the spacecraft. “Not only crew safety, but also ground crew safety, is an important factor,” he said. “Where are the risks, and how can they be mitigated, and what is the best overall sequence for safety of the whole?”

But what is the treadmill actually designed to do? You said, "The tangential velocity always matches the tangential velocity of the wheels." That doesn't answer the question of what the treadmill is designed to do. It makes a (rather undefined) claim about what happens when the whole system is turned on and running. What is the treadmill instructed to do?

NG upper stage will likely end up acting as a crasher stage for a multi-engined lander.

Local TWR is greater than 2 for most reference designs, simply because lunar gravity is so low, but yeah.

Oh, I thought it was clear -- JEB (or another Kerbal) needs to be the payload.

Tin-tin. Right. 1/5 for half of Martian gravity.

Jeb Kerman has decided he's done with the jerks at KSC, and he's going to get as far away as he possibly can. Unfortunately, he only has a few minutes to scrounge parts from the VAB to build his getaway vehicle. The Challenge: Get Jeb as far away from KSC as you can, using as few parts as you can. Rules: There will be separate leaderboards for 2 parts, 3 parts, and so on, up to a maximum of 9 parts. Feel free to enter into multiple categories. Staging or leaving the vehicle is fine. Part count is what initially leaves KSC; doesn't include launch clamps, etc. You cannot use any arrangement which would conceivably allow you to travel indefinitely. So, no solar-powered rover, no glitchcraft, no RTG-powered paddleboat. Also, distance gained from swimming or running does not count. You cannot leave the atmosphere. Score is based on ground distance traveled in the F3 menu. The kerbal must survive. Good luck!

Everything about SMART reuse. Are there any plans to develop autonomous engine landing and reuse? (the little stubby fly-back strap-on liquid boosters) With the impending retirement of Delta IV and the intended replacement of Atlas V by Vulcan, do they anticipate going to a single-vehicle manifest? How is ACES coming along? When do they anticipate the first orbital cryogenic propellant transfer tests?

Don't have to spin up to 1 gee. Going up to, say, 1/5 of a gee will reduce the load on and length of the tether, and leave you with enough muscle mass to handle Martian gravity, but you'll still be able to jump ten times your body height, so stairs are not necessary. The reference was to an early nuclear thermal Mars mission, where the living quarters would be tethered opposite the propulsion unit. Some takeaways from the Mueller speech: Making engine fly 10x you run into "100,000 mile problems" seals wear out, turbine blades and combustion chamber cracks (I bet!) Raptor's TWR will exceed Merlin 1D's (we already knew this) The methane-fueled Raptor is expected to be twice as powerful as the Merlin 1D, with liftoff thrust of 380,000 pounds (and there you have it, folks) Engine development is on track for next year’s anticipated start of short-hop flight tests of the BFR upper-stage spaceship (looks like SpaceX employees in general are very onboard with BFR)

Wait, so now the aircraft is controlling the belt?

You cannot exactly use a method to derive the total timeframe of production if one of your independent variables is the timeframe of production.

I haven't used KOS, but keep in mind that assuming a decent amount of thrust, you will likely begin your landing burn after reaching terminal velocity. So drag is not a significant part of the equation at that point.

FYI, heating-related speed won't come into play here. It's looking for the density of the atmosphere before you get to it, not after.

"The tangential velocity" relative to what? The ground? The plane? The wheel hub? The wheel surface?

As I understand it, the outer shell of the capsule has been replaced in all cases so far.

Airbrake will be designed to, well, brake. So its drag coefficient will be on the order of 1.5-2. Times its cross-sectional area. Atmospheric density depends on so many factors that it's much easier to just use a reference table. You can calculate density based on pressure very easily, but the pressure equation is more difficult. This might help: http://hyperphysics.phy-astr.gsu.edu/hbase/Kinetic/barfor.html

Sure. Take the cross-sectional area of the fairing and use a drag coefficient of 0.21. More: http://www.aerospaceweb.org/question/aerodynamics/q0231.shtml

Yeah, I get that. Was thinking of something more like a ribbon. Trying to figure out if there is a geometry wherein counter-rotating helical ribbon capacitors would couple linearly to the Earth's magnetic field lines.