monophonic

"Day" and "rotation" are not synonymous, and use of the latter does imply sidereal day. That is where @farmerbens question becomes interesting. Indeed if the Earth did not rotate at all around its axis, we would have negative one days in a year. Negative to account for the opposite movement of the sun. If Earth was tidally locked to the Sun, so we had no day/night cycle, Earth would rotate one full rotation around its axis in a year. Add to this the 365 and a bit days we observe, and the answer is indeed one more rotations than solar days. Or 366.24219*360°=131 847,1884°.

Not just a Space Agency either. The Broglio Space Center was an active launch site from 1964 to 1988, and it is still in use as a monitoring and control site. It is also currently being considered for reactivation for launches. Granted the site is operated by the Italian Space Agency, but Kenyan governement is wise to have their own organization looking after them. Plus they have the perfect claim as the real world owner of the acronym KSA. In my eyes that is all the reason a country needs to have a space agency.

We have discovered cultures of bacteria living on the outside of the ISS. In the friggin outside of the ISS, in the vacuum of space. They don't need tardigrades to protect them. They will laugh at the tenuous CO2 atmosphere of Mars. Who knows how many perfect "vacuum" "resets" you can get before something like that exists in your dome? I bet not that many. This might be the same thing you are saying, but let me elaborate anyway. I don't know if it is even possible to draw a meaningful line between adaptation and speciation on asexually reproducing organisms at all. Isn't the standard line between species at whether the individuals can produce offspring that can themselves reproduce? You can't apply that test when the reproduction involves only a single individual.

If your pay slip says NASA, then yes. If your pay slip says anything else, you are a consultant to NASA instead.

There is a lot more science than that in internal ballistics of a gun. Which goes to say the opposite, using black powder in a gun designed for modern propellants, is an equally bad idea. Like, barrel burstingly bad. But I'm not really an expert on this (either), and we are getting off topic, so I'll leave this at that.

It isn't really about how much weight can angle iron hold. It could even resist pushing down into soft soil, if it hits a rock, or a root, or has any semblance of a foundation beneath the undergrowth. There is another angle iron visible at 0:52 in the BBC video. Could have been brought by the investigators, or could be a remnant from some old construction, like a fence. Latter case a foundation would be likely. See how lopsided that propping is? The support point is full one third to one side of the diameter. Round things like that are very difficult to get balanced even when you have perfect placement. Any deviation from absolute perfection and the ring will pivot to the side. Granted having the low side dig into the soil does help, but I'm still doubtful it could keep a half ton ring in place like that. 50kg? Probably as long as the wind stays calm and no-one tries to lean on it. Add to that how flimsy that ring looks, sagging like that at the sides where it is unsupported. It really does look like pressed sheet metal rather than extrusion or machined part. You can see the structure well at 0:36. Even the teething is visible on the inside of the ring. The black colour could be some sort of coating, and there are visible remains of other likely non-metal materials. How it would have looked like in an intact assembly is anybody's guess with what I have here. Anyway, I am certain that there is an engineer or three out there somewhere, who could tell at a glance what exactly that part is called, what is its inventory code, and what it is for. I am equally certain their bosses will not be keen on letting anyone outside their company know any of that.

The way it's propped up in those pics, I say there is no way that thing weights anywhere near half a ton. So my bet is on the Ariane adapter.

The biggest issue I have with quantum theory is, if my highschool textbooks' definitions are to be believed, it is not even a theory at all. It is an observation. A very thorough and comprehensive observation by now, but it can not even try to answer why things happen the way they happen. There are all the interpretations of quantum theory, like multiverse, the one with the wave functions collapses, and whatnot. They could be theories, if there have been any experiments devised that could prove or disprove them. Without those experiments, they are hypotheses. (In multiverse there are infinite universes where that is the correct plural, btw.)

All it comes down to is the non-delivery clauses in the commercial crew contract. Boeing will go whichever way costs less, whether that is pushing through with the currently contracted launches, or canceling Starliner and paying whatever fines they must. Now I do not know what sort of penalty clauses the contract includes, so it very well may be the cheaper option to break it. Even free, knowing how some governement contracts in my country are...

ASRAAM, AIM-9X and probably Python use imaging infrared seeker heads. At least Python is purported to be capable of choosing which part of the target aircraft to attack. I presume such functionality would use pre-AI image recognition technology. This is, as mentioned above by a few posters, a short range technology. However some anti-aircraft missiles do now combine radar and infrared seekers into a dual method solution. These include RIM-66M Standard Missile 2 Block IIIB, and Stunner missile of Israel's David's Sling system. However, at least AIM-9X has been proven to still be at least somewhat vulnerable to simple flare countermeasures ( https://en.wikipedia.org/wiki/Ja'Din_shootdown_incident ). Below is a QF-4 target drone as seen by ASRAAM seeker. Image sourced from a post at f-16.net ( https://www.f-16.net/forum/viewtopic.php?f=18&t=7883&start=18 ).

Thanks! That sounds like a kerbal design all right. I did go through all the links, but all I saw was the black image. I have no account of any kind though, so might not need to be verified to see.

Well, they could use Vulcan for the cargo Starliner (Starhauler?) launches. Of course that would require work to integrate the capsule with the launcher, but not needing to crew rate all that should help some. Also, unless Boeing has already decided to cancel Starliner after current contract, that work is in the engineering roadmap anyway. Whether that can be done in time for launches in 2025 is another question though...

I'm not sure I follow your vectors correctly here. As I understand this, the advancing blade generates more lift while the receding blade generates less. This tries to tilt the rotor sideways, not back to vertical. This effect increases with the airspeed. A helicopter compensates with the cyclic so the receding blade has a higher angle of attack than the advancing blade. A multirotor does not have cyclic control. Are you trying to imply that in a two rotor situation the drone would settle to a drift perpendicular to the line between the working rotors? Also, are you sure the restoring torque you mean will try to restore the rotor axis back to vertical in the world sense and not perpendicular to line of movement? Because the latter is unlikely to be exactly horizontal, and likely to deviate even more from horizontal as the small imbalances cause disturbances. Even a small downward pitch will lead to a crash unless corrected by active measures, and a small upward pitch will lead to a large downward pitch when dropping air density leads to a rotor stall. There is a reason full size helicopters are not considered stable even in a perfect weather. A small multicopter is a lot more susceptible to the atmospheric disturbations, that will disturb even a full size helicopter to a crash, if not actively stabilized by pilot or electronic controls. Also, I realised it isn't possible to arrange the (quad) rotors so in a two rotor situation the remaining rotors would spin the opposite ways. Doing that would couple torque control with rotation about a horizontal axis, which is not conductive to a stable flight. So we end back to needing a minimum of four (fixed) rotors to stay aloft.

Two out of four leaves no control over rotation around the line between the two working rotors. May be survivable in a high school textbook (ignore all other physics) scenario, but you don't need much imbalance in weight or air resistance of the two dead rotor arms, or turbulence in the air to get the airframe rolling uncontrollably. Yes, someone needs to mention the CH-47. Those have control over the rotor to rotor line by varying the blade angles on either side of said line. Cyclic control could make two engine situations survivable, however the cost and complexity would be exorbitant. Technically doable, though. RC helicopters existed already in the 80s, probably earlier. Even if the rotor could run in reverse, you would lose all torque control in that situation and start rotating wildy around the vertical axis. Another unsurvivable scenario right there. You simply need at least four and an even number of fixed rotors working to have control of the flight attitude. You can replace one rotor by adding tilting on another, but the total number of moving mechanisms stays the same. Plus you complicate the math, add to the count of different parts required and one rotor needs to be connected via a moving joint. All things conspire to make four rotors the optimal number.