Listy

Employees don't even have to leave en masse for problems to occur. The potential risk of Kompramat provided by said 'law' must have foreign intelligence services licking their lips in anticipation. (And maybe some domestic competitors too). It goes without saying that it's not just SpaceX that's at risk - any tech company or defence contractor in the state is potentially exposed.

Apparently someone at NASA did comment in the media at the time that the RTG would 'probably keep a few fish warm'.

The RTG's NASA uses are quite well shielded by layers of iridium, graphite & ceramic to protect it in the event of a launch mishap. The one on Apollo 13 could not be deployed on the Moon & subsequently survived a very fast unplanned reentry & is now sitting intact at the bottom of the Pacific. They put out a decent amount of heat, so curling up to an RTG might be a good way to stay warm on those cold cold Martian nights

This paper describes the various camera systems on Perseverance in great detail. The cameras being used during the EDL stage are all wired into a central data storage unit on the rover via USB & the wires will be cut as each stage separates (ending communication with that camera). The down looking camera on the skycrane will work right up until the rover touches down & the rover tether is cut, so we should get good pictures of what the sky crane landing process really looks like. I guess the risk of interference during landing ruled out using a wireless link for any of these cameras, although if the Mars copter onboard successfully flies it will send images & other data back to the rover via radio.

I wondered about this as well. After I had panels put on my roof I soon noticed a dip in electricity output twice a day at roughly the same time. I realised the shadow from a small vent pipe was passing across part of one panel and then another panel a bit later, and it caused the whole string of panels to decrease their power output. I had to cut the pipe a bit to resolve that. There are options for shade as well - most modern panels have bypass diodes, and you can get optimisers or micro inverters for each panel that bypass shaded panels/cells as well, so I suppose the ISS array must be designed in a way that compensates well for the effect of shading. I'd assume the old arrays are more trouble than its worth to replace entirely, especially if they are still productive. Not sure how they'd be disposed of either.

The panel trusses have a gimbal mechanism so one side tracks the sun, keeping that side fully illuminated. It looks like the new panels will permanently shade parts of the old panels, but they are much more efficient, so it will cancel out - the original panels could generate up to ~220kW when installed , but that has now dropped to 160kW over the last 15-20 years. The new panels generate an additional 120kW, and will bring power generation back up to 220kW, so it appears about 60kW is being shaded / lost. I suspect they probably can't increase power output much above the original 220kW as the ISS solar charge controllers (or whatever the ISS equivalent is) won't be designed for it. The difference in size between the two arrays neatly illustrates the improvements made in panel efficiency over the last 20 years or so.

I recall reading earlier this year that at least one of the leading vaccine candidates (I think the German BioNtech/Pfizer one) was screened against a library of about a dozen different SARS COV2 viruses with modified spike proteins, and it produced a satisfactory antibody response against those mutants. Also, (fingers crossed) if the current COVID spike protein is about as efficiently infectious as it can get, then it might be that any variants that do slip the vaccine net are also slower spreading. Judging by the flu season we've just had in the Southern Hemisphere (or rather, haven't had), I'd be inclined to think that flu is a lot less infectious than COVID. Many countries struggled through the winter months trying to deal with COVID, but influenza just never became widespread (even in vulnerable places without significant flu vaccination programs), despite the season being well underway by early March. Here in Australia, there hasn't been a single flu death since late March, and only a few hundred detected cases, despite record levels of testing. The fact that cases are popping up occasionally shows that it is still in the community, but vaccinations, social distancing & enhanced hygiene is keeping it suppressed. Rhinovirus on the other hand, is just spreading merrily as if nothing has changed this year, even in the city of Melbourne, which endured a 12 week lockdown over winter. Heaven help us if we ever encounter a pandemic rhinovirus ...

It's a grim comparison, but AF447 fell belly first into the Atlantic with a roughly similar vertical speed - about 55m/s...

I'm pretty sure my sports socks are alive, and they thrive on a healthy diet of sweat Sphagnum peat moss was widely used (& still is a bit) for wound bandaging and for nappies/diapers due to its highly absorbent and antimicrobial properties. I'm pretty sure it's dried out when used but some mosses can be revived after long periods of being dry, so it could be considered alive perhaps.

He's not very consistent with his tantrums either - didn't say much at all when the Shanghai factory was closed for 2 months

As well as N for any base, you sometimes see other codes like 'W', (either A or T), or 'S' (meaning a G or C) in sequence readouts. The various nucleic acids codes in use are listed here. DNA / RNA sequencing can be a bit messy at times.

I think the PCR tests will be the mainstay of diagnosis & quarantine / contact tracing efforts, as it's cheap, fast, high throughput and can be (and are being) 'home brewed' if/when imported reagents cant be accessed. The limiting factor is access to labs with real time PCR machines etc. That's where antibody tests will be very valuable, although by the time you show an antibody response, you're either in hospital or past peak infectivity, so contact tracing will always be a week or more behind the virus as it moves through a community. A quick and reasonably accurate viral antigen fingerprick / saliva test would perhaps be better, but I don't think good ones exist yet. If it was cheap enough it could be used to complement temperature checks at high risk areas like hospitals and aged care centers. I wonder if Russia is being 'helped' by demographics - compared to western Europe, the Russian population is young and skews female, and this virus (like many others) is roughly twice as fatal in males than non-pregnant females, regardless of age or health status. (I'm not sure if pregnancy is a risk factor with covid, but it certainly is for influenza - in past flu pandemics pregnant women have tended to be the highest at-risk group.)

Some early serology tests had very high false positives of 5-15% - too high to be useful, and it's unfortunate that people rushed to publicise pre-prints involving these tests (and small numbers of participants, just to make things worse). Even the validated tests still have false positive rates of ~0.5%. Much better, but it will still meaningfully affect your data if you are looking at a population with low infection numbers of say 1-2%, and utterly useless for population testing in countries like Australia or China where daily infection rates are 1 in a million or less. Some preliminary findings from large seroprevalance studies in France, Spain, & the UK were released in the last week and all showed infection numbers of about 5-7%, or about 8-9 million people out of 160 million. With roughly 100,000 deaths in those 3 countries combined, I think that means a likely infection fatality rate of about 1 - 1.5%, which is broadly in line with most calculations over the last 4-5 months. The interferon therapy is interesting. I know someone who had covid-19 in early April, and statistically speaking, she probably should be dead - she's in her 80's with a significant co-morbidity (a nasty lymphoma - hospital is how she got infected). But she's still here, virus free and doing well. I believe one arm of her treatment plan is interferon-alpha, but I don't know if it was being administered in the days/weeks before her infection. n=1 of course ...

That's eerily close to how it's being done! This from an Australian journalist staying in an apartment in Beijing - "Up to four guards man the only entry to my compound. They take your temperature each time you walk in and check you're carrying an "entry/exit" pass issued only to residents ... In recent months, temperatures have become like intangible keys. As long as you're below the fever threshold, you can enter compounds, supermarkets and cafes..." . They're also doing the whole SMS thing - the Alipay cash app sends you a traffic light warning on your phone every day, green is OK, orange for self-isolate now, & presumably red is for anyone infected. Police check your status everywhere you go. https://www.abc.net.au/news/2020-03-08/coronavirus-quarantine-in-beijing-no-fun-bill-birtles/12032244

For some idea of the scale of testing undertaken in China, the WHO joint mission report on COVID in China noted that: "By 23 February, there were 10 kits for detection of COVID-19 approved in China by the NMPA, including 6 RT-PCR kits, 1 isothermal amplification kit, 1 virus sequencing product and 2 colloidal gold antibody detection kits. Several other tests are entered in the emergency approval procedure. Currently, there are at least 6 local producers of PCR test kits approved by NMPA. Overall, producers have the capacity to produce and distribute as many as 1,650,000 tests/week." While it doesn't say how many people are actually being tested in China, I'd suspect a decent fraction of that 1.6 million kits per week capacity was being utilised, perhaps less so now. It's worth noting that the current tests being used around the world do not have the sensitivity to reliably detect COVID19 in an asymptomatic person, the false negative rate is high until about the time when symptoms also start to show. For a true idea of how mush asymptomatic transmission occurs, we'll have to wait for widespread serological testing later in the year. However, given the gigantic scale and thoroughness of the contact tracing & quarantine program in China, and the fact that most cases (between 80-100% according to the WHO report) could subsequently be traced back to contact with a person/s who were either symptomatic when contact occurred, or became symptomatic within a day or two, I think the case numbers & percentages seen in China might be close enough to 'real'. If widespread asymptomatic community transmission were occurring I think we'd be seeing more 'random' cases in China still, but most of the ~100 cases reported each day now are apparently occurring either within families in self-isolation, or among people returning from overseas.

https://jalopnik.com/gm-debuts-new-ev-platform-it-pioneered-two-decades-ago-1842094994 Indeed, they came up with a skateboard platform dubbed 'Autonomy' about 20 years ago and then promptly shelved the idea. Realistically, battery tech was not ready for widespread use in vehicles at that point, but it feels like they (and the whole auto industry really) have allowed Tesla way too much of an EV head start now

yes, 'corona' means crown in latin. It's worth noting that the per capita case load in South Korea is now higher than China, and Italy & Iran are not far behind.

The good news about Coronavirus is that not everybody gets sick: https://jamanetwork.com/journals/jama/fullarticle/2762028 The bad news about Coronavirus is that ... not everybody gets sick.

Mobile payment platforms are the norm in China, cash payments are a rarity in cities & increasingly in rural areas too: https://daxueconsulting.com/payment-methods-in-china/ It can make life tricky for western visitors who are used to cash or credit cards, and get stuck having to try to download an appropriate payment platform when they want to buy things from a shop after arriving. Mobile phone surfaces are also regarded as significant reservoirs of disease, so if Coronavirus can be transmitted via surface contact (I think the evidence is currently inconclusive), cashless payments might reduce, but not totally eliminate transmission risk.

Vikram lander found - most definitely not in a single piece! https://www.lroc.asu.edu/posts/1131

Somebody tried: http://theworstthingsforsale.com/2018/11/26/the-bluetooth-fork/ There is no piece of technology, no matter how old or simple, that can't be made worse by sticking bluetooth on it and connecting it up to the internet!

Saw the Starlink-2 train pass almost directly overhead tonight. Was able to see about 30 of the 60 satellites during the ~10 minute pass - the sun had only recently set so the sky was still quite bright. Most satellites that I saw were spread out with 20-30 second gaps between each one that I could see, but there were a few clumps of 3-4 close together still. Most seem to be slowly spinning/tumbling at the moment, with brightness varying from invisible/very dim to fairly bright (4-5 reached Sirius level bright) over about a 10-20 second period.

The big challenge for Starlink if it really does want to expand beyond serving rural westerners, is that mobile internet in the developing world (in Asia at least, which is by far the most affluent and populous 'developing' region) is already pretty fast, almost ubiquitous, and insanely cheap (cents per gigabyte cheap). Plus, you don't need to buy and carry a special base station around with you. The idea that there are billions of people just waiting to get online in the developing world but can't because there's no phone line nearby doesn't reflect today's reality - everywhere in the world, most people almost certainly live within the range of a phone tower these days. Today it's much more likely that people who remain offline either see no need for the internet, or they can share a phone with a family member who does have internet, or its simply unaffordable - in which case, they won't be able to afford Starlink either. Telecommunication companies outside the west also tend to be fairly young and a lot more dynamic than the dinosaurs we are used to - much like a certain upstart rocket company that's popular around here in fact . Certainly in Asia, if Starlink comes close to being competitive, those companies wont just sit still - they'll respond by dropping prices even more, and rolling out thousands of new phone towers faster than Elon can chuck satellites in the sky. If that happens it will be a win for consumers, but it might not be a win for Starlink.

I wonder how far south the typical catch zone will be for a sun synchronous launch? If there's no boost back involved then somewhere in the southern ocean roughly between Wellington & Christchurch? Mahia peninsula is already on the fringe of the roaring 40's, and a number of Rocketlab launches have experienced weather delays so far. The chopper pilots will be earning their pay trying to catch a spent rocket in a 50 knot westerly.

If a lunar base is ever established, it also sounds like NASA & SpaceX would both be keen to get a better handle on how best to stop everything nearby (habitats, rovers, equipment, astronauts etc) from being turned into a sieve every time a rocket lands or takes off nearby and starts flinging dirt around at 3km/s in an environment where there's no air to slow the debris down. http://www.planetary.org/blogs/guest-blogs/2014/0419-forensic-ballistics.html " The exhaust of the Shuttle’s solid rocket boosters pulled several thousand bricks from the wall of the launch pad’s flame trench, slammed them into each other, creating many thousands of fragments, and blew them as far as a kilometer from the pad."