The Tech Forum

[chaotic neutral observer]

This type of generator is interesting at a theoretical level, but I don't see it being very practical.
The researchers currently report 25 mW/m², and think they can improve to 0.5 W/m².  In comparison, a solar panel can give you 200 W/m².

And, as with solar panels, this technology requires a clear sky. If it is overcast, the sky temperature will be higher, and reduce the available temperature difference. This approach requires the ground to be warmer than the sky to work.

[Brother Mythos]

True, the power generation is not impressive. But, I do find the technology interesting.

This article caught my eye because I remember well the big industrial search, of years ago, for energy to be harvested from waste heat.

[Faust]

Solar Panels require some rare materials. If this is just simple LED diode it could have applications in power scavenging or when doing it over long empty distances like empty highway regions

[chaotic neutral observer]

Solar Panels require some rare materials. If this is just simple LED diode it could have applications in power scavenging or when doing it over long empty distances like empty highway regions

Today, you can get a 25 mW (rated) solar cell that measures under 2 cm² for $2.57 (in quantity).
500 mW brings that up to ~$10.

Even if you consider that the actual power out of these solar cells is likely to be below the rating, I would say the cold sky thermoelectric approach is optimistically a couple of orders of magnitude behind the point where it would be competitive.

RTG's are only viable because there is a huge temperature difference involved.

[altered]

This is ridiculous. I have no idea how it can possibly work. I fucking love it.

[Brother Mythos]

"Lockheed Martin Selected to Develop Nuclear-Powered Spacecraft"

As per the article:

"Lockheed Martin [NYSE: LMT] has won a contract from the Defense Advanced Research Projects Agency (DARPA) to develop and demonstrate a nuclear-powered spacecraft under a project called Demonstration Rocket for Agile Cislunar Operations (DRACO). The project will represent a rapid advancement in propulsion technology to benefit exploration and national defense.

DARPA partnered with NASA's Space Technology Mission Directorate on the DRACO project, as both agencies will benefit from this leading edge technology. The in-space flight demonstration of a nuclear thermal rocket engine vehicle will take place no later than 2027."

Faster, Farther, More Agile
Chemical propulsion engines have long been the standard for spaceflight, but for humans to travel to Mars, they will need much more powerful and efficient propulsion. Nuclear thermal propulsion (NTP) engines offer thrust as high as conventional chemical propulsion with two-to-five times higher efficiency, which means the spacecraft can travel faster and farther and can significantly reduce propellant needs. They also enable abort scenarios on journeys to Mars that are not possible with chemical propulsion systems."

I haven't hear much about NTP in recent years. So, it will be interesting to see the rocket engine this R&D project manages to build.

Here's the link:   https://news.lockheedmartin.com/2023-07-26-Lockheed-Martin-Selected-to-Develop-Nuclear-Powered-Spacecraft