Thank you.

So the idea is to use these in RTGs to replace the thermocouples used now?

Would it make sense to use them e.g. as the back face of solar panels, or as an extra layer on a spacecraft's radiators? Or is the power you can get from lower-grade heat sources too little to be worthwhile?

The USA and USSR have launched a few dozen spacecraft with RTGs, out of more than 12,000 satellites launched in total. That's not "many".

No. The N-1 suffered from these problems:
1. lack of testing on individual engines. The engines were not built to be restartable. They used e.g. pyrotechnics to open valves, meaning that valve could only be opened once. They tested NK-15 engines by building a batch of 6, testing 3, and if those tests were successful, putting the remaining 3 on the rocket.

2. lack of testing on individual stages. This was because the Soviets didn't want to spend years, $ and thousands of tons of concrete to build the huge test stands that would be needed for such tests. They did their stage tests by launching rockets.
They used the same strategy for Proton, which went into successful service after 14 test launches with lots of explosions.

3. lack of money. The USSR space budget was 1/20 of the Apollo budget.

4. lack of support from the leader of the Soviet space effort, Mishin. This meant N-1 development was not pushed, but allowed to languish.

5. lack of quality control. One launch failed due to welding slag entering an engine.

6. many engines on a stage, with no way to test the behavior of that engine cluster on the ground due to #2.

SpaceX has none of these problems. Yes, they've blown up a lot of rockets. 0 of those failures were in any way similar to the problems seen on N-1 launches. In contrary: those tests show SpaceX has designed Starship to operate reliably with 33 engines, demonstrating engine-out capability and resilience to violent engine failures.

Starship development is similar to N-1 development in the early use of launch tests. For Starship, this has not replaced stage testing on the ground. It just gives early access to a flight regime that cannot be tested on the ground: reentry.

Patience.

The flex is that so far, the refurbishment of just the launch platform for SLS has cost about as much as the entire Starship development.
Now, Starship development hasn't finished yet, but it's clear that SpaceX has a better handle on making access to space cheaper than NASA does.

Antennas aren't perfect. A directional antenna is more sensitive in one direction than in others, but does not provide perfect isolation. So a jammer radiating into the antenna from the side can still work.

For Starlink this gets more complicated because they use a phased array, the antenna elements of that array cannot be directional, so the jamming signal comes in at close to full strength and has to be separated from the satellite signal by the processor.

For everyone in the manufacturing chain, there's a difference:
- cost: what they pay to design and build, or procure a widget
- price: what they'll sell that widget for.
The difference between the two is their margin, ie the profit they made on the sale.

Did that help clear things up, or should I include some insults for you?

It's not surprising to me people aren't bothering to learn to read analog clocks any more. They stink. They force you to count ticks or estimate the distance between digits, adding up clues until you get to the time. Digital clocks are much easier to read.

Analog clocks are a fossil from a bygone era. Better solutions have been able for decades.

Thanks, I needed a good laugh today.

And yet you ended up with "one nation under God".

A: The cost of the lessons!

Ride ends but the car signals it can't move? Message the last rider "you forgot to close the door, we'll bill you $1/minute until you fix this".

There are perfectly viable commercial alternatives. I learned home improvement from Tim Taylor, and I've only died 42 times so far.

I compared to wafers because semiconductor wafers are made from a single crystal of silicon which has to be grown gradually, just like these CZT crystals.