sevenperforce

I can't imagine anyone surviving 200 C for ten seconds.

If all you have are the sausage casings, with no sausage filling shipped from Russia, then all you really have is an effective enema. EDIT: Shocked that the filter allowed enema.

Well, I would say that if a patient were to breathe an inert gas at close to boiling temperatures for a quarter of an hour, the chance that they will die of the coronavirus becomes extremely slim. As this is the leading institute of emergency medicine, I'm sure they know what they do. It's 92° Fahrenheit, not 92° Centigrade. It's also a mixture of oxygen and helium; I would assume at higher than ambient GOX ratios. Nitrogen reacts with certain amino acids and changes the blood pH while helium does not. Presumably the virus has a narrower allowable pH range than humans. It is a very good idea.

I guess you can get true known positive and known negative by individual microscopic exam?

It's particularly bad when you don't have any good way to actually test the tests.

We really are flying blind in so many ways with this. The strong genetic dependence of hACE2 expression would provide a basis for widespread genetic resistance to SARS-CoV-2 pathology. Its role in hypertension, for example. Concentrations of genetically-restricted populations would also explain a wide range of tested asymptomaticity.

Falcon 9 has now surpassed Atlas V for the number of successful launches. Detractors can argue that the supposed cost savings of reuse have yet to materialize, since SpaceX isn't showing its internal financials. But it's hard to argue with the time savings of refurbishment and reuse. There's no way they could have hit this launch cadence using only brand new Falcon 9s. It's why RocketLabs is seeking to do the same thing...not to cut costs, but to increase cadence.

To get into circular orbit with the ground-tangential speed of Earth's rotation, you'd need to be much higher than geostationary orbit. Earth's surface rotates at 460 m/s; even the moon orbits at more than twice that. Not even sure you could do it inside Earth's Hill sphere. Imagine a carnival carousel. You're on a bike, freewheeling and holding onto the edge as it carries you around. A rope attached above you extends out 30 feet to another biker, also freewheeling as the carousel carries him around. You want to join the other biker, so you pull out a section of rope, tie one end to the edge of the carousel, and then slowly begin to release it. Unfortunately, you will NOT drift out slowly and radially to join the other biker; rather, you will fall behind because he has much more angular momentum than you do. You'll have to pedal to increase your speed as you move away from the carousel even though your angular speed remains constant.

I have several very young kids in close quarters so I suspect we are at an exponentially higher risk for intra-household transmission. Biggest factor IIRC is the size of the initial dose, because that impacts antibody production. Not sure which way this goes, tho. Some data from roughly a week ago in NYC may prove instructive. Look at the third column: cases per 10,000 for age group. Let's assume, for the sake of this analysis, that there's no age-dependence on susceptibility to infection, only on susceptibility to pathology. Let's also assume that the disease is infectious enough that all age groups have a roughly equal chance of exposure. Neither of those are strictly true, but there's a fair chance that they cancel each other out, Fermi-wise (those more vulnerable to infection are less likely to be exposed, all other things being equal). These assumptions suggest that total cases are roughly equal across age groups and so the third column actually reflects the percentage of symptomatic cases. If the actual number of cases is at least 210.4 per 10k across all age groups, then you recalculate the estimated number of cases and estimated hospitalization rate. Moreover, death rate as it stands is rather useless; what you want is the death rate per actual hospitalization: NYC COVID-19 Cases AGE EST. CASES (min) SYMPTOMATIC HOSPITALIZATIONS EST. HOSP RATE DEATHS DEATHS/HOSPS 0-17 36,818 5.5% 190 0.52% 3 1.58% 18-44 70,648 56.2% 4,304 6.09% 284 6.60% 45-64 43,258 87.5% 10,182 23.54% 1449 14.23% 65-74 14,717 89.2% 6,147 41.77% 1511 24.58% 75+ 11,477 100.0% 6,853 59.71% 2935 42.83% Taken in aggregate, this suggests 176,918 cases and 104,158 symptomatic cases, for a symptomaticity rate of 59%. That number will drop with serological testing, but it is reasonably close to the 48.3% symptomaticity found on the Diamond Princess. If the true symptomaticity rate is 48.3%, then the actual odds of COVID-19 putting you in the hospital in the 18-64 aggregated age group (i.e., most American workers) is 10.4%, and your odds of death from hospitalization is 11.9%. That's a pretty damn small bowl of Skittles.

One of the things we have to make sense of is the number of healthcare workers who are getting infected and dying, including those in low-risk groups. A possibility is genetic susceptibility to infection alongside genetic resistance to the disease's pathology. If anyone should have gotten it outside the healthcare industry, it would have been me -- I am in one of the most internationally-trafficked cities in the world and I was riding the metro daily until it shut down. I've had tightness in my chest and an occasional dry cough for weeks. Yet if I had it, there's a 100% chance I would give it to my wife and kids, none of whom have shown any signs of illness. If I had to wager, I'd say all of us have it (or have had it) and are simply asymptomatic or nearly so. Here in the US, DJT Junior was panned in 2016 for comparing Syrian refugees to poisonous Skittles, but this is a situation where the metaphor is perhaps more apt. The elderly and those with pre-existing conditions are at high risk, but even among the low-risk groups there is evidently a significant portion of the population with an elevated risk of severe health outcomes. It doesn't matter how young or healthy you are, or whether you are a healthcare worker, or whether you take all kinds of precautions; one of the Skittles in this (relatively small) bowl of Skittles will put you in the ICU, and have no way of knowing which one. And that's one of the terrifying things here. (statistically, "you have no idea which of these hundred Skittles will kill you" is equivalent to "you have no idea whether you are one of the 1% of the population who is deathly allergic to Skittles")

Amazingly the first COVID-19 death in the US has now been dated to February 6. https://www.sfchronicle.com/health/article/First-known-U-S-coronavirus-death-occurred-on-15217316.php [snip]

That's kind of like saying that an English longbow would scale up well, so long as you had a giant to bend it.

Voltages required are far too enormous to be workable, and contrary to the inventor's claim it would not scale well at all due to the required energy density.

Yes, you can design in static roll stability, but without this the aero corrective forces are not proportional to the angle of deflection from the passively stable orientation. It all comes down to angle of attack and the position of the lift vector. In a conventional aircraft, which flies close to prograde, the angle of attack is low and the lift vector is behind the center of mass, pointed dorsally. Roll is independent of yaw and you can roll without much if any rudder input. Once you are at a high angle of attack, like the Shuttle or a similar spaceplane, roll and yaw become coupled because your lift vector points both dorsally and forward. If you roll left, the lift vector tugs your nose to the left. When you have a lifting-body spaceplane like the Shuttle Orbiter or the X-37, designed to enter within a very narrow aerodynamic regime and then glide to a landing, you can constrain the vehicle's pitch to the envelope where yaw and roll are coupled, and thus you need only the split body flaps to handle everything. If I remember correctly, the Orbiter's horizontal stabilizer and rudder/speedbrakes were completely out of the airstream during re-entry and only became useful during glide. This was the original planned design for the BFR as shown in the 2016 IAC. However, this only works when you can constrain your lifting-body envelope to some very narrow parameters. If you intend to re-enter with varying cargo weights or on various worlds, you need much more flexible pitch control. On a vehicle that flies completely with body lift at an extremely high angle of attack, like a skydiving Starship, roll and yaw become uncoupled again and your roll no longer impacts your yaw at all. The good news is that at high enough angles of attack, you can rotate around the yaw axis with very little torque because there's no corrective aero force, just like you can rotate around the roll axis with low torque during level flight.

Yep, changes to heading are 100% a matter of controlling yaw. A conventional plane uses roll and yaw in combination to change heading, but when you are using body lift, you use pitch to control the magnitude of the lift vector, roll to control sink rate and translation, and yaw to control heading. With a conventional plane there is no aero resistance to roll. With a body lift regime, there is extreme aero resistance to roll but none to yaw, so RCS is fine. You just don't want to be in a situation where you are burning RCS continuously to oppose aero correction forces.

Controlling yaw with just two flaps in the coronal plane, actuating ventrally or dorsally, is impossible. You can control roll easily, though. Lift the left flap to decrease drag and roll left, and vice versa. Lift both to decrease aft drag and send the center of pressure forward of the center of mass, pitching up; extend both to increase aft drag and pull the center of pressure aft of the c enter of mass, pitching down. The reason for four flaps is that you actually can control yaw aerodynamically. Order the forward flaps to roll left and the rear flaps to roll right, and you'll yaw left. If you only have two flaps, you can't nudge yaw without a high AoA, but there's no barrier to using RCS for yaw with low AoA.

I was inspired by @QF9E's excellent re-creation of Apollo 15, complete with all the fancy bits and little-known configurations, so I decided to attempt to do the same with Apollo 17. My rocket is currently upwards of 300 parts and only getting bigger, which is now rather astounding. I've read almost the entire Saturn V User's Guide. Some interesting facts I've learned in the past week that will be reflected... The iconic conical fairings on the base of the S-IC first stage were blown before retrorockets were fired. On Apollo 15 there were only 4 retrorockets on the S-IC and no ullage motors on the S-II interstage, as they determined that no propellant settling was needed. However, the low separation caused S-IC to blow up, so they added back the four missing retro motors, but still had no ullage motors for 16 and 17. The steering motor on the nose of the LES was deactivated for aborts which took place after pitchover. During nominal missions, an umbilical was retained between the Command Module and the LES so that they could trigger the abort motor if the jettison motor failed to pull the LES and its fairing clear of the nose. This was never used. Rather than deploying experiment packages via rover, the crew of the Apollo 17 mission deployed five remotely-triggered explosive charges to be monitored by the seismic monitors that had already been laid down in previous missions. The mission deployed two experiments at the landing site: a gravimeter (that failed) and another seismic monitor. Their rover carried a gravimeter on board to take measurements as they buggied around. It also carried an electromagnetic emitter that was monitored by instruments on board the descent module to determine the composition of lunar soil. There was only one reaction wheel on the Apollo 17 Saturn 5, in the sub-sat, and it was only activated after deployment. There were 12 RCS thrusters on the CM that never fired until SM jettison and then handled pitch and roll independently. Four of the 16 RCS thrusters on the SM were set to fire continuously to depletion after SM jettison to push it away from the CM. The LM had 16 RCS thrusters on the ascent stage that were used along with the descent engine during descent and landing, partially depleting the maneuvering tanks on the ascent stage. The S-IVB third stage had two solid ullage motors and 8 RCS engines, 6 of which were used for roll, pitch, and yaw and 2 of which fired continuously to keep propellants settled. The S-IVB third stage had batteries, two solid-state antennae, and two hydrogen tank vents. After the CSM performed transposition, docking, and extraction of the LM, the S-IVB stage used RCS to point and then vented the hydrogen tanks to push it into a lunar impact. It impacted more shallowly than any other stage, at 55 degrees. The center engines on the first and second stages were fixed while the outer ones gimballed. And much, much more!

I really do wonder from this if they are going single-flap-pair. Midbody wings with vertical flaps might be enough, with RCS. Similar to a return to the IAC2017 version.

This would work if you had a single bolt, but not with a triangle of bolts.

Start with a permanently-welded nut on the skin of starship and a tile manufactured with an internal bolthole. Double-sided bolts come in two sections that can be current-welded together. One section is screwed into the welded nut; the other into the tile. Place and current-weld, permanently joining the two bolt-sections into one. When you need to remove the tile, you smash it and unscrew each bolt from the underlying nut.

Unfortunately the most recent antibody tests don't work. https://www.propublica.org/article/he-spent--500-000-to-buy-coronavirus-tests-health-officials-say-theyre-unreliable

I think this has been addressed before but air cannot be magnetized without being ionized. Ionization either requires extreme voltages or extreme heat.

Perhaps the tiles are not removable? I would have imagined that the tiles are removable, but maybe they are only designed to remove if they need to be replaced, in which instance you just smash them anyway.

That's what I originally assumed too, but... https://insideunmannedsystems.com/going-bladeless/

High-res closeup of the bolted-on TPS tiles shows no visible fillers or caps whatsoever: I wonder how they did it.