cubinator

I might do some math in a bit regarding the actual heat transfer (math below), but qualitatively in the meantime: Have you ever seen someone dunk a bouquet of flowers in liquid nitrogen for a few seconds, then take them out and shatter the flowers like glass? It's that cold. I've frozen wet ice cubes together in an industrial freezer at somewhat survivable temperatures in just a few seconds - I think on Titan you'd have a hard time even drawing in your first unprotected breath as your mouth and nose freeze shut. Disclaimer: I just googled around for some heat transfer coefficient values and eyeballed a fairly low fluid velocity arbitrarily The heat transfer rate is going to depend on the heat transfer coefficient and the temperature difference. For air, I'll say the heat transfer coefficient is 25 and the temperature difference is 21 degrees (assuming dealing with surface body temperature of 25 degrees). In that case the heat transfer rate is 525 W/m2. For Titan, I'll assume the heat transfer coefficient is 1.5 times that for air (not really sure of the exact value) and the temperature difference is 205 degrees. In this case the heat transfer rate is 7687.5 W/m2, almost 15 times more. For water, with a temperature difference of 21 degrees and a heat transfer coefficient of 5000, the heat transfer rate is 105000 W/m2. So water seems to be quite a bit better at wicking heat than Titan's air, but let's see how much of a threat it is anyway. Water (which you contain a lot of) has a specific heat capacity of 4.186 J/g*degree C. So if you have 1 mL of water in your mouth spread over an area of, say 10 cm2 or 0.001 m2, at a temperature of 310 K, the temperature would need to be lowered by 37 degrees to reach the freezing point and begin to form ice, corresponding to an energy of 154.88 Joules. At the heat transfer rate we calculated earlier for Titan's air, and taking into account the smaller area, if you drew in a breath at 2 m/s or so, the water in your mouth would reach 0 degrees Celsius at t=20.15 seconds. Ok, so that's not complete instant solidification, at least in your mouth. For comparison with my example from before, liquid nitrogen apparently has a heat transfer coefficient of 300 to 800, around the same as air. That means that indeed, imagining dunking stuff in liquid nitrogen is a decent analogy to what would happen to it on Titan. And while we've found out that swishing liquid nitrogen in your mouth *might* not *instantly* freeze some of your spit, I think we can be absolutely sure that for no amount of time would it be pleasant. Furthermore, your eyes are more exposed and likely a bit cooler than the inside of your mouth, so we can be sure that should your face be exposed to the atmosphere you would have significantly less than 20 seconds before your eyelids start to freeze. You might be blinded around the same moment you realize there's no oxygen in what you're breathing - a frightening scenario. Anyway, it seems that Titan is definitely very dangerous to expose your face in, but if you should accidentally expose some skin out of your jacket, say, with your glove loose around your wrist, you might have up to 20 seconds to get your glove back on before you start getting serious frostbite - and beyond that, there is no mercy. All of this assuming you don't touch a rock with your bare hands, wade in the shores of Kraken Mare, or encounter a gust of wind in your totally rad wingsuit, any of which would make things much, much worse.

I may be wrong on this, but it's also possible at least some of the crew went to bed.

Discussing roll orientation of the lander...

I dunno, it's basically a bunch of companies independently having a 'first try' at landing on the Moon, isn't it? If if was one company that had had five tries I'd see it differently. I hope the congress critters can see past that too. Well, I don't think the lander they'll be trying with is going to be "small"...

The air pressure is no problem, people withstand way more when going underwater in submarines or diving. The temperature is cryogenic (like liquid nitrogen range) so you need to keep yourself insulated and avoid skin contact with the air, as it will start freezing your flesh solid on contact. Since the air is more dense than on Earth, it'll also be more effective at transferring heat out of you. You also need your own breathable air supply, of course, and make sure your airways are sealed against the atmosphere, because the methane is quite poisonous. Water is probably what most of the ground is made of, so if you dig some up and warm it up you can probably do whatever you need with it. If you're keeping your habitat comfortably warm, then you should make sure the part of it that's sitting on or right above the ground is not conducting any of that heat. The first problem would be that it would not be efficient. The second would be that it would start melting the ground...and your habitat would start to sink. If you've got so much hot air inside your habitat, though, you might consider one that allows itself to lift into the sky as a balloon.

Cylinders and spheres are not only for following streamlines in-atmosphere, they are also the best structural shapes for pressure vessels. So we won't see a complete absence of them in space.

It flies, but barely. Ditch the wings when flying slow over the drop zone.

Here is a half-decent full run of the song! https://drive.google.com/file/d/1eJNyOO_gWe2kSr3xCTyLc6531jMTuNi1/view?usp=sharing Played on my Conn 800 at home.

Re: high volcano walls: Run a ski/cable lift down the side.

Iclicked this.

The science they manage to squeeze out of these things years and decades after the missions they were designed for is truly inspiring. Voyager is in a unique place for us, the farthest that we've ever touched, and it will be missed when it finally disappears into the void. I hope they can keep in touch with it for a few more years, before its final endless mission.

I like the independence of being able to go wherever I want, whenever I want. Actually putting in the work to make the car not hit stuff can be more of a chore.

I feel like it'd have a hard time doing even that when the throwaway launch has the same price tag as 20 Falcon launches.

I'm guessing June.

Missions requiring large numbers of launches in close succession Rocket can only fly 0.5 times per year at best Costs much more than Apollo for a rocket with less performance

Good luck with that part. I've been at it for longer than it takes to get from Earth to Mars.

I really hope we keep our stupid wars confined to Earth...

Hope they fill that thing with plenty of bungees or a lot of astronauts are going to end up on long rides from one side to the other.

I really like the Duna theme from KSP2, so I made a transcription and have been learning to play it on the organ. I still have a lot of practice to do, but I was too excited not to share what I've done so far. Here you can listen to the first part of the song: https://drive.google.com/file/d/1cpgTPePGYnc_AJlgKJP5_gztEZmb2feu/view?usp=sharing I can play pretty much all of the parts individually without trouble (yes, even THAT part!) but putting them all together and tightening it up to the point where I have the brainpower available to think about stops and the character of the sound will take a while. I envision myself making a proper recording on a nice pipe organ somewhere in town once I've learned the whole thing.

Amazingly, I transcribed essentially the entirety of the Duna theme in one evening tonight - minus a small part of the arpeggio, which I worked out on a previous day. It seems less complicated after looking at it for a while...but I'm sure it will feel even more complicated when I have to play it with both hands and feet.

Good observation. See how the dark patch in the sand stretches outward away from Ingenuity? I think that's likely where the blade hit the dirt and scooped it up. I wonder if Perseverance's microphone would have been able to pick that up...

Having your shirt pulled off and a huge hole opening near your seat might change your mind on whether to consider whether you're "allowed" to move away.

I wish the TWR display in the VAB would show its value when it's below 1. Currently if I have a ship with TWR < 1 it's not possible to tell how close I am to making it viable, or at a glance if it could launch from another body.

I think they should just make the deltaV bar red to indicate where the fuel is projected to run out, and put a little "/!\" sign by that spot. Especially when the game fails to determine that my full tanks have any deltaV at all as soon as I toggle engine groups.

Made plans to be in the center of the Moon's shadow in April. Now for the cloud gamble to play out....