YNM

Yeah, sadly that was doomed to be disintegrated not long after landing. But from now on we can expect more audio from Mars, then.

How often are they planning to record audios from the surface ? I'm honestly wondering now if the microphone is actually the one worth more than the cost by a large margin because that's a serious troubleshoot resource if any. Stuck motors ? Check the sound. Stuck mechanism ? Check the sound. Stuck in a rock ? Check the sound of how it got stuck...

Seriously they should give us all the sound recordings as much as possible as well. Sound is one aspect overlooked on robotic explorations I think, while sure it's our eyes that takes in most informations from our surrounding, sounds are the first indication often of what's coming and what might go wrong. Hope if they put a lander to Titan (again) or something they'll feature a microphone again. EDIT : Been there, done that.

And we can hear winds on Mars for the first time. This is amazing. I wish the microphone could remain on all the time, who knows if we ever hear anything remotely odd...

idk, the size of the rocks looks much closer to here I suppose...

Now that's a hover... on another planet 20 light-minutes away ! EDIT : Standalone video uploaded :

"commercial, off the shelf cameras" confirmed, GoPros on Mars

Or the current NASA TV stream link were started so long ago and they don't want to change it. Most of the event livestreams are broadcast earlier on the NASA TV stream than the dedicated stream links.

I honestly wonder if the continued weirding of the conditions down here on Earth would eventually push the precedent for developing the means for living on completely uninhabitable world further, however. While this would still have no effect on the fact that economic incentives of living on Mars itself be close to nil it'd at least raise the incentive on technological developments that'd enable the activity at one point.

Amazing just how many problems can be solved with thinking of the problem in the form of that particular field...

Further search of Draim Tetrahedral / Tetrahedron lead me to these : US Patent from 1989 : Someone have made it in KSP : Old thread of people calculating the orbital parameters on this very forum for various in-game celestial bodies : It does rely on eccentric, inclined orbits, so I guess the "regular tetrahedron" part is definitely not possible, also I think it's impossible to do without having the distances between the satellites to be fixed in any way, shape or form due to the nature of eccentric orbits.

I found a US Patent from 1989 giving that the minimum required satellites to maintain coverage of one hemisphere (north or south) is 3, and they do make for a constant triangle. The 4-satellite whole globe coverage isn't quite as neat however - either that or the visualization is not adequate enough. (original paper, but behind a paywall.) The latter is apparently known as Draim's tetrahedral... so QED ?

Yeah, what I was saying is a pressurized space large enough where you don't need to worry about running out of air immediately in a fire (and also not generating hurricane-force winds through some of the space). Ah, for those you don't need it to be super high. Suppression systems could still be hidden in other features closer to the floor.

Fires can generate intense airflow around it, that's why they can spread very easily in crowded cities both in the past and the present. Also the hab material would most likely include insulation which might contain combustible materials, although I could imagine that the insulation might just be left outside of the proper pressurized space, but then there's a question of what the liners are made of, and where the cables and conduits are and what are they made of, etc etc. Yeah, the aesthetics are definitely not going to be as pleasing as a futurist would like to think. That being said however I imagine if you have enough people to live on Mars for them to complain about the lackluster appearance of the whole place we might need to move something like underground or just straight up a whole transparent dome kind of affair.

Has that ever happened on a submarine ? Depends a lot on the module construction I'd say. If it's an interconnected module and you haven't cut off the burning module from the rest then you'd lose pressure throughout the complex plus the flow of air from the rest of the place will carry more oxygen. (I still insist that no one is going to walk outside just to go somewhere within the colony, except if it's an external thing like solar panels or so.)

I'd like to counter. Fires are dangerous in Antarctica because it is extremely dry (so no moisture to delay the flame), and possibly you won't have anything to extinguish it with (and is very difficult to, as if you were to throw a bucket of water they'd freeze, while if you use non-freeze fire retardant that's a lot of fire retardant), and also it's extremely windy and the fire will jump over to other buildings within close distances easily. Hence why people barely fight the fires once it has engulfed one building, rather they try to keep everything else out of the reach of that fire. Some bases do have very good supplies built in already however that they can somewhat run your typical firefighting scene with water and all. On the ISS the current policy is basically to extinguish all fires before they get out of hand, but unlike a colony they don't exactly have to overlook a large amount of pressurized area. I imagine for Mars colony you'd have some amount of automatic fire suppression, as there's some amount of gravity so you can use liquid fire suppression like one would on Earth. Maybe if it got so large one could go and cut off the affected module. Also probably to deal with the fume you'd have emergency oxygen supplies throughout the habs and passageways like there are on submarines.

Problem with dimensions, I suppose.

I'd say that there might've been something like a bloom of at least extremophiles. I think most of their expectation is just single-celled stuff rather than anything very complex. Depends on your agency I suppose. There are missions that are being extended to more than twice the length of the original mission, ie. Hayabusa2. And if this rover is easier to command and steer around compared to older rovers (it can look after itself rather than having to be plotted all the time) then it'll be a valuable tool to have as long as it's working. Curiosity itself has survived for 8 years, so expect Perseverance to do about the same. The drone however is only designed for 30 days of operation, so I hope they really wait until the time is right to deploy those.

I think (under my terrible understanding of GR via friedmann equation) the point @K^2 was making is that if you insert energy somewhere without much energy then you should bring the same energy out of it. This is even true for cosmological purposes I suppose, ie. dark energy to "explain" why the universe is expanding at an accelerated rate...

Good to hear. Hopefully they can optimize what we need for an interplanetary greenhouse (the least material from homebase, the most produce and nutrition value). I'd say that fire on Mars is as bad as fire on the ISS. If there are fire suppression system on the ISS then there'd be fire suppression system in a Mars colony too.

Cygnus separation. Yet another supply for the outpost... I mean, even the Perseverance landing and the press conferences that happens around it were only streamed on 720p. It's partly because they're designed for the payload they were meant for. They aren't an add-on piecemeal upgrade to a design from the 60s anymore. That being said, Atlas V, Delta IV, Ariane 5 (and Ariane 6), FH, HIIA/B (and H3), GSLV, and Long March 5 would like to disagree as they do feature SRBs/LRBs and even co-boosters.

Could also be that they just copied the stream over rather than a dedicated stream (albeit a dedicated link is available but it mostly only goes to allow people to interact through the live comments). At least 720p does conserve bandwidth on my end...

idk why but all of the livestream from NASA on YouTube only maxes at 720p, incl. the NASA TV stream.

Lunar surface isn't exactly 0g / free-fall. Plus those are trusses, which goes into rigid structures. Dishes that doesn't need to move can be closer to non-rigid catenary system.

The dish would be made out of wire mesh, which you can fold down into smaller area. So dimensions aren't a problem. You're kind of right on the amount of material it might need, though. Arecibo have about 85,000 m2 of dish area, while FAST have about 196,000 m2. I'm honestly not sure how thick do we need the wires be for it to be viable, but assuming a wire mesh with pitch size (size of the 'holes' / spacing of the wires) of 6.35 mm x 6.35 mm (1/4" x 1/4") the quoted weight from a fence manufacturer using 0.46 mm diameter galvanized steel wire is 4 kg for 9 m2 of mesh (about 445 g/m2), which works out to 88 tonnes (FAST sized) or 38 tonnes (Arecibo sized) dish. The heaviest mesh I see from this manufacturer is for 5 cm x 5 cm pitch using 4 mm dia. steel wire which makes for ~4 kg/m2 (so 10 times as heavy). We haven't talked about the support structure for the receiver, the jacking for the dish, the observation equipment and data handling (copper cables as well) etc. But it's still less than for a mobile 7 m or 12 m dish antenna array numbering up to a hundred I guess. Not sure how heavy those would end up being as well however... Then again because it's simpler perhaps producing the wire mesh itself could be the subject of space mining/extraction and manufacturing technology testing, given aluminum is aplenty over there. Making wire mesh is kind of easy as well (just straight extrusion then spacing and ERW).