PakledHostage

That funnel-web video is impressive! I had heard of them but I didn't realise they were quite that big. Probably because the Aussie who first told me about them described them as a "small spider". It is all relative and what you are used to, I guess... She had an unreasonable fear of bears, but at least bears don't hide in your shoes.

I would trap it and toss it outside but Michigan is probably too cold for that at this time of year... Do you have a heated garage you could take it to? Or you could just accept its presence. Détente. I had a basement bedroom when I grew up, and I once had a spider living in a corner for about a year and a half. It did its thing; I did mine.

I don't have time to work it out right now (I am supposed to be working), but I am interested in Z-man's point about vacuum Isp vs. the Isp that K^2 calculated for the bottle at something close to 1 atmosphere pressure. I think it is a relevant point. Also, maybe we could get a better estimate of the total delta-V if we can find a video that shows how empty the bottle is when it is finished expelling liquid.

The equations on my MathCAD spreadsheet.

Just for reference, I worked out the rough amount of delta-V that it would take to lower an object's PE from the ISS's orbital altitude. NORAD posts the current orbital elements of the ISS as: This means that the ISS is currently orbiting at roughly 420 km altitude with an eccentricity of 0.0005920, or about ±2 km. Assuming a circular orbit about the Earth at 420 km altitude: - Lowering an objects PE to 300 km would take about 35 m/s delta-V. - Lowering an object's PE to 200 km would take about 63 m/s. - A 100 km PE would require about 94 m/s delta-V. - A 0 km PE would require about 123 m/s delta-V.

I think that is a really interesting idea. Pilots have the option of landing overweight, but the aircraft must be inspected for structural damage after landing. It isn't that onerous an inspection but it must be done before further flight, and a more detailed inspection will be required if the initial inspection finds any warning signs. Also, fuel dumping systems aren't always installed. When they are, dumping usually takes place in airspace that has been designated for the task. Swissair flight 111 had been heading towards such an area when they crashed. They were under the mistaken belief that their problem wasn't urgent and were going to dump fuel in the designated area rather than land overweight or seek permission to dump fuel anywhere. As the situation became more dire, they were given permission to dump fuel before reaching the designated area, but by then it was a moot point.

But that is kind of besides the point. Turboshaft engines are susceptible to foreign object damage as well. The A-10 is arguably the most highly regarded CAS aircraft, despite any vulnerabilities that it may have. It represents a strong counter-argument to Dragon01's belief that turboprops make better CAS aircraft than jets.

Erm... What about the jet powered A-10 "Warthog"? It is probably the most formidable CAS aircraft out there.

The one-off Scaled Composites Pond Racer was a noble attempt to build an aircraft that was faster than WWII fighters for use in the annual Reno Air Races. The Pond Racer was commissioned by Bob Pond because he was concerned that each year at the Reno Air Races, valuable and historic aircraft were being crashed and destroyed. It crashed in 1993, killing the pilot. No replacement was ever built.

I remember that we even discussed it on these forums and that you were involved in the discussion, but I couldn't find the link. I looked for it earlier this evening. Do you remember when it was? Maybe it was before the April Kraken attack?

rpayne88 already gave a good and knowledgeable correction to Seret, so I'm going to tackle the point about UAV safety. As Nibb31 pointed out, airliners are not as automated as UAVs for safety reasons, not because it can't be done. The accident rate for UAVs is very high, even though most of the UAVs that achieve the dubious honour of being included in the statistics are operated and maintained by professional military crews. An NBC News story cites a reference that claims that UAV's have an accident rate 30 to 300 times higher than general aviation aircraft (i.e. private pilots flying mostly piston powered aircraft). Autoland systems on airliners are "mainstream", but they are only safe because they are monitored closely in real time by human crews. The ground based and airborne segments of the system also continually need to be tested to remain qualified. But even despite the demonstrated risks, it makes sense to design Skylon to fly itself. It is much more "cutting edge" than an airliner. If they succeed at all, the margins are going to be very slim. It is likely that attempting to man rate the system, at least initially, could make the difference between success and failure of the project.

Not quite. They cannot take off on their own and the auto flight systems do not have control of the flaps or landing gear on any of the Boeing or Airbus aircraft that I am familiar with. Autopilots also cannot interact with ATC. An autopilot is just a tool to reduce workload. It allows the crew to focus on what humans are good at but the pilots still need to manage the autopilots through the various phases of a flight.

No kidding, eh? I am surprised nobody has jumped on 8? Citation needed.

Thanks, everyone, for your help answering user's questions. And to you, cake>pie for your efforts. Feel free to use the changes you made to my mod for your own purposes but please don't distribute it. It does not sound like your derivative work is significantly different from my original project to warrant being its own mod. I will consider incorporating your ideas in a later revision (with appropriate credit given) if there is enough demand from the user base. And with regard to the accuracy/availability of navigation solutions outside the orbit of the navsat constellation: It is probably because of how the algorithm calculates whether a satellite is located above the horizon or not. I admit that I hadn't actually considered that case when I wrote it. I will fix it in the next update. P.S. Navigation solutions are intentionally restricted to only work within the same SOI as the navsat constellation. This is for the sake of realism and in keeping with the limitations of existing real-world GNSS technologies.

But it can also be very pleasant if the sun is shining. Especially at the end of a long Edmonton winter. And that, I think, is why Kerbin Dallas Multipass' use of the phrase "subjective temperature" is so appropriate. Wind chill temperature is subjective, while a wind chill factor is less so because it doesn't have any implied physical meaning. It is more like an extra dimension to the temperature that gives useful information but isn't as prone to misunderstanding or as volatile a fuel for exaggeration.

No, instead of putting all of our eggs in one basket we'd spend the money on dozens of robotic missions and do far more valuable science in the process. The benefits of developing that technology would help solve some of the problems that humanity faces here on earth too.

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I think at this point you can safely go to bed. The Kp index is still stubbornly low (i.e. less than 3) and it'll have to get over 5 for you to have much of a chance of seeing it. The NOAA ovation site also isn't showing much activity currently.

Not really. The idealised tables and empirical equations that define wind chill temperature make assumptions about the surface temperature of the body that is being cooled. This is why they talk about the effect of wind chill on exposed skin. The convective heat loss of someone standing naked is obviously different than that of someone wearing a heavy parka because the difference in temperature between the air and the surface of the person is smaller when wearing a parka than it is for someone standing naked. The heat transfer rate isn't a linear relationship either because the convective heat transfer coefficient is also dependent on the air temperature in the boundary layer. You can get away with having an exposed face at -40°C if there's no wind, but it will be darn uncomfortable or even dangerous to have an exposed face at -30°C and exposed to 20 kph winds (roughly -40°C wind chill temperature). This is why it makes more sense to use a wind chill index than a wind chill temperature. It is less likely to be misinterpreted as having any physical meaning or to be used as an excuse to exaggerate. You're in Portland, but I wonder if that is also true in places like North Dakota or Minnesota? It would be important to know how severe the conditions are before venturing out, so I am surprised that the National Weather Service doesn't include any sort of wind chill factor in its weather reports in places where it matters?

For reference, the ISS location at the time of stage 1 burnout:

There was a story on the CBC this morning about how the media has been over dramatising the recent period of cold temperatures in North America. I don't know how many time's I've heard the phrase "polar vortex" (usually said in an alarmed tone) in the news in the past week... It got me thinking about how wind chill factor has been distorted in recent years. When I grew up on the Canadian prairies, wind chill factor was quoted in Watts per square metre. When Environment Canada said it was 3000 W/m2, you knew it was extreme and that you had to cover every last bit of exposed skin. Maybe even wear ski goggles if you had to be outside in the wind for long. Media outside of public broadcasters would usually "translate" the Environment Canada numbers into an equivalent temperature, so eventually even Environment Canada capitulated. Now everyone reports wind chill factor as a wind chill temperature. Trouble is that people don't seem to know anymore what it means when the wind chill factor is reported as "-1 000 000 °C !!!!". People believe that it actually is that cold. I have even been asked how car thermometers are calibrated so that they don't read -40°C when the ambient temperature is -20°C and you're driving at 100 km/h. My question then for this forum is: What (if anything) can we do about it? Does it matter? Or is it another example of the dumbing down of our society? Maybe W/m2 is too technical for most people but what if we were to drop the units and call it an index? It is an idealised number anyway. The idea of using an index that is less prone to misinterpretation and exaggeration appeals to my engineering sensibilities, but maybe I'm the one who should lighten up? What do people do in countries outside of North America?

About 1630 UTC now on the 9th and so far nothing... Solar magnetic field direction data (Bz) from the Advanced Composition Explorer spacecraft isn't currently favorable for auroras and the NOAA's Kp index remains stubbornly low. Here's hoping things improve and we get a good show? It is supposed to stay cloudy for the foreseeable future where I am, but maybe someone will be able to get some good photos and post them to this forum? Current NOAA ACE spacecraft data plot Current NOAA Kp Index plot

The University of Fairbanks Aurora forecast says it reaches us on the 9th of January.

Another good site for monitoring current aurora activity is: http://helios.swpc.noaa.gov/ovation/#

I will take that as a compliment. Thank you.