Viton / FKM / FPM / Fluorosilicone

Viton is a trade name for a type of fluorocarbon rubber developed by DuPont specifically for the aerospace industry. The ASTM in the USA uses FKM as the generic term, but DIN/ISO in Europe and the rest of the world prefer FPM. It is often the most expensive of the three rubber types discussed here. FKM is compatible with petroleum fluids (including dino and synthetic lubricants, pure gasoline, and diesel). FKM is also fully compatible with water and ethylene glycol coolants. Most FKM grades are also a little better than NBR at handling biodiesel and ethanol-blended fuels, although FKM is still not the best choice for ethanol -- and it is a downright poor choice for nitromethane. Its high 400F operating temperature makes FKM a better choice for sealing engine, transmission, and differential oil systems.

Why is it the most energy efficient to change orbit inclination while crossing the equator?

Specifically, it's most efficient to do a plane change at one of the two "nodes" where the origin orbital plane intersects the destination plane. ANASIS-II is destined for geostationary orbit, so its destination plane is the plane of the equator.

Any orbit around a single massive body lies in a single plane. It should be clear that you can't enter an equatorial-plane orbit at any point except a point directly over the equator. Coming from any non-equatorial orbit, there are two points on the orbit where the planes intersect. If you try and do a burn to enter a particular destination orbit from anywhere else, you just push the intersection point a little further around the orbit.

(It's super easy to demonstrate this in Kerbal Space Program, but kind of hard to put into words!) //

A great aid to intuition is to remember one principle about orbit changes: if the engine is off, the orbiter always returns to same point one orbit later.

So for any orbit change, if you want to do only a short burn, it has to be at a point that is common for both the current orbit and the destination orbit. This applies to inclination changes, altitude changes and basically any orbit change. If the orbits do not have a common point, the change requires two burns and an intermediate orbit, such as Hohmann transfer orbit.

Like Russell's answer details, for a geostationary target orbit those common points are always above equator. For e.g. polar target orbit, the points would be somewhere else.

tr '\0' '\377' < /dev/zero > /mnt/a/1

It will abort with an error when the drive is full.

See https://ss64.com/bash/tr.html for syntax/usage of "translate" ("tr").

translate every occurrence of '0' in /dev/zero to char 255 (377 octal) and send output to file named "1" in directory /mnt/a/

Australia’s national airline has said goodbye to an era of aviation that lasted half a century and encapsulated many major moments in the nation’s history. Qantas’ final 747-400 plane has taken off from Sydney Airport. It paraded off the tarmac with an arc of water jet streams to the applause of onlookers eager to mark…