I can imagine the following scenario:
Propellant tanks are pressurized, bursting the burst disks. Very shortly after, the valves to the combustion chambers are opened, and Super Dracos fire. Later, valves close, Super Dracos shut off, leaving fuel and oxidizer in the tanks. Now the helium pressurization lines and the tanks are at equal pressure. Sloshing causes fuel and oxidizer to travel up these lines (with no pressure differential to prevent it) and eventually meet, causing a small explosion which breaks the helium pressure pipe. Now that this is at low pressure, the rest of the oxidizer and fuel escape and combine.
However, I can also imagine lots of things that might make this impossible - but I don't know if these things are true or not.
Perhaps the Super Dracos always fire until propellant exhaustion.
Perhaps after firing there will always be gravity acting in a direction to prevent propellants from reaching the gas pressurization lines.
Perhaps there will always be enough He flow to prevent backflow.
Perhaps they are going to use burst disks and check valves, but didn't say so.
Woo hoo! A soccer legend replied to me!
So I can put "Hello world" on Github, add a "sponsor me" button, donate $5k to myself and get $10k in return?
Until I read this, it had not occurred to me to wonder whether epigenetics happens in bacteria, or just in eukaryotes.Wikipedia to the rescue:
"While epigenetics is of fundamental importance in eukaryotes, especially metazoans, it plays a different role in bacteria. Most importantly, eukaryotes use epigenetic mechanisms primarily to regulate gene expression which bacteria rarely do. However, bacteria make widespread use of postreplicative DNA methylation for the epigenetic control of DNA-protein interactions."
Alas, I don't know whether this all means the new bug will work less well due to misbehaving epigenetic mechanisms.
Antibiotics don't depend in any way on the genetic code of the bacterium, so it should make no difference initially to antibiotic resistance. However because its code is incompatible with other bacteria, it can't gain or pass on antibiotic resistance to others. So the antibiotic situation is better than nature. If you wanted to use bacteriophages (viruses which infect bacteria) to control them, an approach which is currently rare but might become common, you'd need a virus engineered for this bacterium, you wouldn't find a natural virus that could do the job.
If I were making such a critter I'd eliminate some genes that synthesized something important, then provide that something important to my bacteria colonies as a nutrient*. Then if any escape, they won't be able to survive in the wild. (I'd also use an appropriate level of bio-hazard containment. And I'd expect that some independent safety committee has OKed this research. However, that is all supposition - I have no direct knowledge of the safety precautions in this instance.
* Vitamin C is this for humans, except for the 'not present in the wild' part. Most animals can synthesize their own, but humans need to get it in their diet.
Changing the genetic code of a virus would make it a non-virus.
This works in a bacterium because you can change both the code and the interpreter at the same time.
I'm on the fence on whether BFR will work for orbital launches (but I really hope it will). However I don't believe the "Earth to Earth" mass transportation idea will work any time before, say, 2050:
The safety challenges are enormous. Reentry (for such a large vehicle, and without ablative shields) and propulsive landings leave much less margin for error than even current spaceflight. Compared to current commercial aviation, it is many orders of magnitude more dangerous.
The noise of launch means spaceports will need to be over a hundred km from any large city.
Airliners operate in almost any weather. If you're selling a super-fast transportation link, it won't go down well if 20% of flights are delayed for hours for weather. So now liftoffs and landings have to be able to happen in high winds and rain.
They have a lot of catching up to do. Rocket Lab did the same - started with a sounding rocket, and moved on to a small sat orbital rocket - but they launched their sounding rocket in 2009. Although Rocket Lab is the most prominent, and the only one I'm aware of to have launched satellites commercially*, there are dozens of other companies aiming for this small sat launch business. Vector Launch is one which is probably very close to achieving an orbital launch. If it takes Interstellar Technologies 5 years (which seems optimistic to me) to go from sounding rocket to orbital launch vehicle, they'll be entering a crowded market, in which there are competitors who have already paid off their R&D investment.
Having said all that, I wish them luck. Rockets are cool, and I'm happy to see more of them.
* Falcon 1 and Pegasus could be counterexamples, depending on how you count things, and I think there may be an Israeli company also.
It isn't just drug companies supplying dollars that make drug trials happen. Patients participating in the trial risk their health on unproven treatments, for the purpose of improving medical knowledge. It is unethical to suppress the trial results.
When an airplane lands in crosswinds (i.e. wind direction is not parallel to the runway) its nose is pointed at an angle to the runway. When it touches down, the plane needs to abruptly swivel so the nose is pointed down the runway, as now it is being directed by wheels rather than wind. In strong crosswinds, this operation looks really freaky. Here are crosswind landing videos.
Here we have a plane with landing gear much much further apart than any ordinary plane. I wonder whether this makes it harder to do that abrupt swivel? If so, the plane will have much greater restrictions on crosswind landings.
When the engine is driving a generator, you can optimise the engine and generator to operate at whatever torque and RPM works best.
If the gasoline engine is supplying electricity to a hybrid, it doesn't need a very wide RPM range. It can run at optimum RPM at all times except briefly when starting up and shutting down.
For cars and cell phones, energy density matters a lot. For stationary home and industrial scale installations, it matters much less. Are lithium ion batteries still the best choice for such applications? (For the purpose of this question, I'm only considering batteries. I am aware that there are many other industrial scale electricity storage technologies proposed or in use.)
In principle, once you have the continuous communication anywhere in the world, you can program the transponders to start churning out black-box type telemetry whenever a dangerous anomalous condition is detected in the plane (e.g. stall, upset, fire.) So it is a somewhat separate issue, rather than a completely separate issue.
Such emergency uploads aren't going to eliminate the need for black boxes: the bandwidth won't be available to transmit everything, and sometimes the vital clue is something that happened 30 minutes before the crash. (And sometimes the interval between detecting 'something is wrong' and total destruction is a few seconds.)
Type louder, please.